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Assessment of fore-, mid-, and rear-foot alignment and their association with knee symptoms and function in patients with knee osteoarthritis. Clinical rheumatology OBJECTIVE:Hallux valgus, flatfoot, and rearfoot eversion are well-known major complications of knee osteoarthritis (OA). However, there is no consensus on the association between these foot malalignments and knee symptoms or function. Thus, this study aimed to examine the association between foot alignment and knee symptoms or function in patients with knee OA. METHODS:Female patients aged ≥ 50 years with symptomatic knee OA participated in this study. Knee symptoms and function were assessed using the Knee Society Scoring System (KSS). Hallux valgus, navicular/foot ratio, and leg heel alignment were used as the forefoot, midfoot, and rearfoot alignment indices, respectively. The navicular/foot ratio was defined as the ratio of the navicular height to the total foot length. We performed multiple linear regression analysis to examine the associations between foot alignment and knee symptoms or function. RESULTS:Seventy-eight participants participated our study. KSS symptom score was significantly associated with navicular/foot ratio (regression coefficient [β], -0.30; 95% confidence interval [CI], -109.2 to -20.5; P = 0.005), knee extensor strength (β, 0.32; 95% CI, 0.02 to 0.09; P = 0.004), and age (β, 0.24; 95% CI, 0.01 to 0.32; P = 0.036). KSS function score was not associated with foot alignments but with knee extensor strength (β, 0.40; 95% CI, 0.10 to 0.33; P = 0.001) and body mass index (β, -0.35; 95% CI, -2.82 to -0.66; P = 0.002). CONCLUSIONS:Knee symptoms were significantly associated with midfoot alignment in patients with medial knee OA. This suggests that lower navicular height in patients with medial knee OA may relate with the alleviation of knee symptoms. Key Points • In patients with medial knee OA, midfoot alignment was significantly associated with knee symptoms in patients with medial knee OA; however, knee function was not associated with foot alignment. • Lower navicular height in patients with medial knee OA may relate with the alleviation of knee symptoms. 10.1007/s10067-022-06421-7
The relationship between foot posture index and resting calcaneal stance position in elementary school students. Cho Yongjin,Park Jin-Woo,Nam Kiyeun Gait & posture BACKGROUND:Static foot assessment is commonly performed in clinical practice to classify foot type for prescribing therapeutic interventions. Foot posture index is known to be a reliable indicator for foot position. Resting calcaneal stance position angle is used widely to determine foot posture and manufacture orthoses for pediatric flat foot patients. However, the relationship between foot posture index and resting calcaneal stance position angle in elementary school students is currently unclear. RESEARCH QUESTION:To investigate the relationship between foot posture index and resting calcaneal stance position angle in elementary school students. METHODS:Between January 2016 and December 2017, 208 elementary school students (average age, 10.3 years; range, 8-13 years) were enrolled for this study. All students were examined physically by one practitioner to measure foot posture index and resting calcaneal stance position angle. Age, gender, and body mass index were analyzed for factors associated with flat foot prevalence. This study was conducted as a retrospective comparative study. Associations between foot posture index and resting calcaneal stance position angle were determined by Pearson's correlation analysis. RESULTS AND SIGNIFICANCE:When measured by foot posture index and resting calcaneal stance position angle, the overall prevalence of flatfoot was 29% and 24% in the right foot and 26% and 23% in the left foot, respectively. Resting calcaneal stance position angle and foot posture index score showed moderate correlation in Pearson's correlation analysis (left side foot: kappa value = 0.710; right side foot: kappa value = 0.704). CONCLUSION:There is a moderate correlation between foot posture index and resting calcaneal stance position angle in elementary school students. Thus, both foot posture index with proven validity and reliability and resting calcaneal stance position widely used in the manufacture of insoles can be used as important biomechanical evaluation tools for feet in clinical settings. 10.1016/j.gaitpost.2019.09.003
A Novel Deep Transfer Learning-Based Approach for Automated Pes Planus Diagnosis Using X-ray Image. Diagnostics (Basel, Switzerland) Pes planus, colloquially known as flatfoot, is a deformity defined as the collapse, flattening or loss of the medial longitudinal arch of the foot. The first standard radiographic examination for diagnosing pes planus involves lateral and dorsoplantar weight-bearing radiographs. Recently, many artificial intelligence-based computer-aided diagnosis (CAD) systems and models have been developed for the detection of various diseases from radiological images. However, to the best of our knowledge, no model and system has been proposed in the literature for automated pes planus diagnosis using X-ray images. This study presents a novel deep learning-based model for automated pes planus diagnosis using X-ray images, a first in the literature. To perform this study, a new pes planus dataset consisting of weight-bearing X-ray images was collected and labeled by specialist radiologists. In the preprocessing stage, the number of X-ray images was augmented and then divided into 4 and 16 patches, respectively in a pyramidal fashion. Thus, a total of 21 images are obtained for each image, including 20 patches and one original image. These 21 images were then fed to the pre-trained MobileNetV2 and 21,000 features were extracted from the Logits layer. Among the extracted deep features, the most important 1312 features were selected using the proposed iterative ReliefF algorithm, and then classified with support vector machine (SVM). The proposed deep learning-based framework achieved 95.14% accuracy using 10-fold cross validation. The results demonstrate that our transfer learning-based model can be used as an auxiliary tool for diagnosing pes planus in clinical practice. 10.3390/diagnostics13091662
Biomechanical Comparison of External Fixation and Compression Screws for Transverse Tarsal Joint Arthrodesis. Latt L Daniel,Glisson Richard R,Adams Samuel B,Schuh Reinhard,Narron John A,Easley Mark E Foot & ankle international BACKGROUND:Transverse tarsal joint arthrodesis is commonly performed in the operative treatment of hindfoot arthritis and acquired flatfoot deformity. While fixation is typically achieved using screws, failure to obtain and maintain joint compression sometimes occurs, potentially leading to nonunion. External fixation is an alternate method of achieving arthrodesis site compression and has the advantage of allowing postoperative compression adjustment when necessary. However, its performance relative to standard screw fixation has not been quantified in this application. We hypothesized that external fixation could provide transverse tarsal joint compression exceeding that possible with screw fixation. METHODS:Transverse tarsal joint fixation was performed sequentially, first with a circular external fixator and then with compression screws, on 9 fresh-frozen cadaveric legs. The external fixator was attached in abutting rings fixed to the tibia and the hindfoot and a third anterior ring parallel to the hindfoot ring using transverse wires and half-pins in the tibial diaphysis, calcaneus, and metatarsals. Screw fixation comprised two 4.3 mm headless compression screws traversing the talonavicular joint and 1 across the calcaneocuboid joint. Compressive forces generated during incremental fixator foot ring displacement to 20 mm and incremental screw tightening were measured using a custom-fabricated instrumented miniature external fixator spanning the transverse tarsal joint. RESULTS:The maximum compressive force generated by the external fixator averaged 186% of that produced by the screws (range, 104%-391%). Fixator compression surpassed that obtainable with screws at 12 mm of ring displacement and decreased when the tibial ring was detached. No correlation was found between bone density and the compressive force achievable by either fusion method. CONCLUSION:The compression across the transverse tarsal joint that can be obtained with a circular external fixator including a tibial ring exceeds that which can be obtained with 3 headless compression screws. Screw and external fixator performance did not correlate with bone mineral density. This study supports the use of external fixation as an alternative method of generating compression to help stimulate fusion across the transverse tarsal joints. CLINICAL RELEVANCE:The findings provide biomechanical evidence to support the use of external fixation as a viable option in transverse tarsal joint fusion cases in which screw fixation has failed or is anticipated to be inadequate due to suboptimal bone quality. 10.1177/1071100715589083
Chronic deltoid ligament insufficiency repair with Internal Brace™ augmentation. Pellegrini M J,Torres N,Cuchacovich N R,Huertas P,Muñoz G,Carcuro G M Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Patients with chronic deltoid ligament insufficiency (CDLI) present a challenging situation. Although numerous procedures have been described, optimal treatment is still a matter of debate. While the treatment armamentarium ranges from simple ligament repair to complex reconstructions with or without realignment osteotomies, direct repair augmented with an Internal Brace™ device appears to be an attractive intermediate option. We investigated functional outcomes and complications in patients with CDLI operated on using Internal Brace™ augmentation. METHODS:A prospective study was conducted. Patients were included if they presented medial ankle pain and/or giving way, exhibited asymmetric flexible hindfoot valgus, failed conservative treatment, and had a positive MRI evaluated by an independent radiologist. Patients with stage IV flatfoot deformity, neuropathy and/or inflammatory arthritis were excluded. CDLI was confirmed intraoperatively with the arthroscopic drive-through sign. Patients were evaluated preoperatively and postoperatively using FAAM, SF-36 and grade of satisfaction. Paired t-tests were used to assess FAAM and SF-36 scores variation. RESULTS:Thirteen patients met inclusion criteria. No patient was lost to follow-up, with a mean follow-up time of 13.5 months (range 6-21). Preoperative FAAM and SF-36 scores improved from 58.7 to 75.3 and from 60.2 to 84.4 postoperatively, respectively (p<.01). Two implant failures were observed, with no apparent compromise of construct stability. No patient was re-operated. CONCLUSIONS:Our results suggest that deltoid ligament repair with Internal Brace™ augmentation in patients with CDLI is a reliable option with good functional outcomes and high satisfaction grade in short term follow-up. LEVEL OF EVIDENCE:Level IV. 10.1016/j.fas.2018.10.004
Biomechanical Analysis of the FlatFoot with Different 3D-Printed Insoles on the Lower Extremities. Bioengineering (Basel, Switzerland) Insoles play an important role in the conservative treatment of functional flat foot. The features of 3D-printed insoles are high customizability, low cost, and rapid prototyping. However, different designed insoles tend to have different effects. The study aimed to use 3D printing technology to fabricate three different kinds of designed insoles in order to compare the biomechanical effects on the lower extremities in flat foot participants. Ten participants with functional flat foot were recruited for this study. Data were recorded via a Vicon motion capture system and force plates during walking under four conditions: without insoles (shoe condition), with auto-scan insoles (scan condition), with total contact insoles (total condition), and with 5-mm wedge added total contact insoles (wedge condition). The navicular height, eversion and dorsiflexion angles of the ankle joint, eversion moment of the ankle joint, and adduction moment of the knee joint were analyzed, and comfort scales were recorded after finishing the analysis. Compared to the shoe condition, all three 3D printed insoles could increase the navicular height and ankle dorsiflexion angle and improve comfort. Among the three insoles, the wedge condition was the most efficient in navicular height support and increasing the ankle dorsiflexion angle. 10.3390/bioengineering9100563
Stiffness of the human foot and evolution of the transverse arch. Nature The stiff human foot enables an efficient push-off when walking or running, and was critical for the evolution of bipedalism. The uniquely arched morphology of the human midfoot is thought to stiffen it, whereas other primates have flat feet that bend severely in the midfoot. However, the relationship between midfoot geometry and stiffness remains debated in foot biomechanics, podiatry and palaeontology. These debates centre on the medial longitudinal arch and have not considered whether stiffness is affected by the second, transverse tarsal arch of the human foot. Here we show that the transverse tarsal arch, acting through the inter-metatarsal tissues, is responsible for more than 40% of the longitudinal stiffness of the foot. The underlying principle resembles a floppy currency note that stiffens considerably when it curls transversally. We derive a dimensionless curvature parameter that governs the stiffness contribution of the transverse tarsal arch, demonstrate its predictive power using mechanical models of the foot and find its skeletal correlate in hominin feet. In the foot, the material properties of the inter-metatarsal tissues and the mobility of the metatarsals may additionally influence the longitudinal stiffness of the foot and thus the curvature-stiffness relationship of the transverse tarsal arch. By analysing fossils, we track the evolution of the curvature parameter among extinct hominins and show that a human-like transverse arch was a key step in the evolution of human bipedalism that predates the genus Homo by at least 1.5 million years. This renewed understanding of the foot may improve the clinical treatment of flatfoot disorders, the design of robotic feet and the study of foot function in locomotion. 10.1038/s41586-020-2053-y
Association between foot posture and tibiofemoral contact forces during barefoot walking in patients with knee osteoarthritis. BMC musculoskeletal disorders BACKGROUND:Accumulating evidence indicates that abnormal foot posture are risk factors for knee osteoarthritis (OA). However, the relationship between foot posture and tibiofemoral contact force (CF) during habitual weight-bearing activities remains unclear. This study aimed to determine the association between tibiofemoral CF and foot posture while walking. METHODS:In total, 18 patients with knee OA and 18 healthy individuals participated in this cross-sectional study. Foot parameters were evaluated by Foot Posture Index (FPI), Staheli Arch Index (SAI), hallux valgus angle, calcaneus inverted angle relative to the floor as a static rearfoot posture, navicular height, and toe grip strength. In addition, all participants underwent kinetic and kinematic measurements during a self-selected speed gait. The measurement device used was the three-dimensional motion analysis system with a sampling rate of 120 Hz. The musculoskeletal model, which has 92 Hill-type muscle-tendon units with 23 degrees of freedom, was used to calculate tibiofemoral CF. Partial correlations was used to investigate the association between foot parameters and total, medial, and lateral tibiofemoral CF of the first and second peaks while controlling for gait speed. RESULTS:A significant negative correlation was observed between Walking SAI and first peak medial tibiofemoral CF in control participants (r = -0.505, p = 0.039). SAI was also significantly positively correlated with first peak medial tibiofemoral CF in patients with knee OA (r = 0.482, p = 0.042). CONCLUSIONS:Our findings revealed a correlation between the medial first peak tibiofemoral CF and the SAI. This study indicates that people with knee OA and flatfoot have excessive first medial tibiofemoral CF during walking. 10.1186/s12891-022-05624-y
Foot and ankle functions and deformities focus on posterior tibial tendon dysfunction using magnetic resonance imaging in patients with rheumatoid arthritis. Modern rheumatology OBJECTIVES:Posterior tibial tendon dysfunction (PTTD) affects the support of the medial longitudinal arch and stability of the hindfoot. The purpose of this study was to assess the relationships of PTTD with foot and ankle functions and foot deformities in patients with rheumatoid arthritis (RA). METHODS:A total of 129 patients (258 feet) who underwent magnetic plain and contrast-enhanced magnetic resonance imaging were enrolled in this study. Positive magnetic resonance imaging findings were defined as tenosynovitis and incomplete and complete rupture of the posterior tibial tendon. Foot and ankle functions were assessed using the Japanese Society for Surgery of the Foot standard rating system for the RA foot and ankle scale (JSSF-RA) and self-administered foot evaluation questionnaire. Plain radiographs were examined for the hallux valgus angle, first metatarsal and second metatarsal angle, lateral talo-first metatarsal angle, and calcaneal pitch angle. RESULTS:PTTD was associated with motion in the JSSF-RA (p = .024), activities of daily living in JSSF-RA (p = .017), and pain and pain-related factors in the self-administered foot evaluation questionnaire (p = .001). The calcaneal pitch angle was significantly lower in the feet with PTTD than in those without PTTD (median: 16.2° vs. 18.0°; p = .007). CONCLUSIONS:The present study shows that PTTD was associated with foot and ankle functions and flatfoot deformity. Thus, a better understanding of PTTD in patients with RA is important for the management of foot and ankle disorders in clinical practice. 10.1093/mr/roab084
Do different foot types affect the 6-min walk test capacity of younths with Charcot-Marie-Tooth neuropathy ? BMC pediatrics BACKGROUND:The present study aimed to assess the gait capacity of youths with Charcot Marie Tooth disease (CMT), considering the different foot postures as a grouping variable.  METHODS: The total distance, the predicted distance, and gait velocity obtained during the six-minute walking test (6MWT) were compared between participants with and without CMT. In addition, part of the CMT group completed a 12-month follow-up. The study evaluated 63 participants (CMT group = 31; Non-CMT group = 32) aged 6 to 18, both sexes. Data included anthropometric measures, foot posture index (FPI), the distance (D6), percentage of predicted distance (%D6), and walking velocity(V) in 6MWT. RESULTS:The D6% presented no significant difference between the types of feet in CMT or Non-CMT (p < 0.05, Kruskal Wallis test). CMT presented reduced values of D6, %D6, and V when compared to Non-CMT. CONCLUSIONS:These findings indicate that gait performance was decreased in youths with CMT in comparison to non-CMT. Contrary to what was expected, the cavus foot type did not show lower gait capacity than the flatfoot, suggesting that the types of feet alone did not determine differences in gait capacity within the CMT group. 10.1186/s12887-022-03338-7
Effects of a 4-Week Short-Foot Exercise Program on Gait Characteristics in Patients With Stage II Posterior Tibial Tendon Dysfunction. Kim Jinah,Lee Sung Cheol,Chun Youngmin,Jun Hyung-Pil,Seegmiller Jeffrey G,Kim Kyung Min,Lee Sae Yong Journal of sport rehabilitation CONTEXT:Clinically, it has been suggested that increased activation of intrinsic foot muscles may alter the demand of extrinsic muscle activity surrounding the ankle joint in patients with stage II posterior tibial tendon dysfunction. However, there is limited empirical evidence supporting this notion. OBJECTIVE:The purpose of this study was to investigate the effects of a 4-week short-foot exercise (SFE) on biomechanical factors in patients with stage II posterior tibial tendon dysfunction. DESIGN:Single-group pretest-posttest. SETTING:University laboratory. PARTICIPANTS:Fifteen subjects (8 males and 7 females) with stage II posterior tibial tendon dysfunction who had pain in posterior tibial tendon, pronated foot deformity (foot posture index ≥+6), and flexible foot deformity (navicular drop ≥10 mm) were voluntarily recruited. INTERVENTION:All subjects completed a 4-week SFE program (15 repetitions × 5 sets/d and 3 d/wk) of 4 stages (standing with feedback, sitting, double-leg, and one-leg standing position). MAIN OUTCOME MEASURES:Ankle joint kinematics and kinetics and tibialis anterior and fibularis longus muscle activation (% maximum voluntary isometric contraction) during gait were measured before and after SFE program. Cohen d effect size (ES [95% confidence intervals]) was calculated. RESULTS:During the first rocker, tibialis anterior activation decreased at peak plantarflexion (ES = 0.75 [0.01 to 1.49]) and inversion (ES = 0.77 [0.03 to 1.51]) angle. During the second rocker, peak dorsiflexion angle (ES = 0.77 [0.03 to 1.51]) and tibialis anterior activation at peak eversion (ES = 1.57 [0.76 to 2.39]) reduced. During the third rocker, the peak abduction angle (ES = 0.80 [0.06 to 1.54]) and tibialis anterior and fibularis longus activation at peak plantarflexion (ES = 1.34 [0.54 to 2.13]; ES = 1.99 [1.11 to 2.86]) and abduction (ES = 1.29 [0.50 to 2.08]; ES = 1.67 [0.84 to 2.50]) decreased. CONCLUSIONS:Our 4-week SFE program may have positive effects on changing muscle activation patterns for tibialis anterior and fibularis longus muscles, although it could not influence their structural deformity and ankle joint moment. It could produce a potential benefit of decreased tibialis posterior activation. 10.1123/jsr.2019-0211
The comparative morphology of idiopathic ankle osteoarthritis. Schaefer Kristen L,Sangeorzan Bruce J,Fassbind Michael J,Ledoux William R The Journal of bone and joint surgery. American volume BACKGROUND:Osteoarthritis is the most common joint disease and the leading cause of chronic disability in the U.S. However, symptomatic osteoarthritis at the ankle occurs nine times less frequently than at the knee and hip, even though the ankle experiences greater pressure and is the most commonly injured joint in the human body. This study sought to quantify the shape and coverage of the talar and tibial articular surfaces by comparing the three-dimensional morphology of the ankle in patients with ankle osteoarthritis and in those without arthritis, including a subset of different foot shapes. METHODS:We created three-dimensional models of the joint surfaces of ankles with and without arthritis. We fit cylinders to the joint surfaces, and measured the radius of the tibial and talar articular surfaces, the tibial coverage angle of the talus, and the degree of joint skew. We hypothesized that these measurements would be different between those with and without ankle osteoarthritis and among foot types. We evaluated a total of 108 limbs. RESULTS:The mean tibial and talar radii were significantly higher and the mean coverage angle was significantly lower in feet with ankle osteoarthritis than in all other foot categories. The mean coronal skew in limbs with ankle osteoarthritis was significantly higher than in the neutral and flatfoot groups. The high arched feet had several significantly different skew angles from other foot types. No significant differences in joint morphology measures between neutrally aligned feet and flatfeet were found. CONCLUSIONS:Ankles with osteoarthritis had larger tibial and talar radii, a smaller coverage angle, and larger skew angles than ankles without osteoarthritis. Together, these findings suggest a flatter ankle joint with less stability, depth, and containment and reduced articular constraint and support. 10.2106/JBJS.L.00063
Impact of the Subtle Lisfranc Injury on Foot Structure and Function. Foot & ankle international BACKGROUND:The subtle Lisfranc injury is the disruption of the osteoligamentary complex between the first cuneiform and the second metatarsal, resulting in minor widening of this space that is often difficult to detect with plain radiographs. In this study, we assessed the results after treatment of the different stages of subtle Lisfranc injuries, focusing on their impact on foot arch anatomy and functionality at short- to midterm follow-up. METHODS:A retrospective study including patients treated in our center for a subtle Lisfranc injury between 2012 and 2019 was conducted. Demographic, epidemiologic, radiographic, and clinical data were obtained and assessed, focusing on foot arch structure and foot function, which was evaluated with the American Orthopaedic Foot & Ankle Society (AOFAS) midfoot score and the Foot Function Index (FFI). RESULTS:A total of 42 patients with a mean age of 49 ± 17.5 years were included, with an average of 4.3 years' follow-up (range, 1-8). Stage I injuries according to Nunley classification represented 19% and were treated conservatively. Stage II (66.7%) and stage III (14.3%) injuries were treated operatively, via osteosynthesis with screws (74%), K-wires (19%), or plates (7%). Flattening of foot arch after treatment was observed in 42.9% of patients, with significant increases in Costa-Bertani (12 ± 7 degrees), Hibbs (7 ± 6 degrees), and Meary (3 ± 1 degrees) angles. Other complications included complex regional pain syndrome (28.6%) and painful hardware (23.8%). Secondary joint arthrodesis was needed in 16.6% of patients. Chronic pain was present in 71.4% of patients with a mean visual analog scale (VAS) pain score at final follow-up of 4 of 10 points. Results in AOFAS midfoot score and FFI were 87.4 ± 8.3 and 15 ± 6.4, respectively. CONCLUSION:The subtle Lisfranc injury shows dissociation between the initial relatively mild radiographic changes and important future complications. Chronic pain and foot arch flattening were not uncommon. Overall foot function in the short- or midterm was found to be modestly diminished in this somewhat heterogenous cohort. LEVEL OF EVIDENCE:Level IV, therapeutic case series. 10.1177/10711007211012956
Total and distributed plantar loading in subjects with stage II tibialis posterior tendon dysfunction during terminal stance. Neville Christopher,Flemister A Samuel,Houck Jeff Foot & ankle international BACKGROUND:In subjects with stage II tibialis posterior tendon dysfunction (TPTD), the function of the tibialis posterior muscle is altered and may be associated with a change in total and distributed loading. METHODS:Thirty subjects with a diagnosis of stage II TPTD and 15 matched control subjects volunteered to participate in a study to examine the total and distributed plantar loading under the foot during the terminal stance phase of gait. Plantar loading, measured as the subject walked barefoot, was assessed using instrumented flexible insoles. A secondary analysis was done to explore the contribution of flatfoot kinematics to plantar loading patterns. RESULTS:Overall, there was reduced total plantar loading in subjects with stage II TPTD compared with controls. Accounting for differences in total loading, the presence of clinically measured weakness in subjects with TPTD was associated with reduced lateral forefoot loading. Medial longitudinal arch height was significantly correlated with loading patterns but explained only 21% of the variance in observed loading patterns. CONCLUSION:Subjects with TPTD who are strong exhibited loading patterns similar to controls. Changes in total and distributed loading during terminal stance suggest there are altered ankle mechanics at push-off during the functional task of gait. CLINICAL RELEVANCE:Strength, in the presence of TPTD, may be important to stabilize the midfoot during gait and might be important in rehabilitation protocols. 10.1177/1071100712460181
Anatomic study of the deltoid ligament of the ankle. Panchani Prakash N,Chappell Todd M,Moore Garrett D,Tubbs R Shane,Shoja Mohammadali M,Loukas Marios,Kozlowski Piotr B,Khan Khurram H,DiLandro Anthony C,D'Antoni Anthony V Foot & ankle international BACKGROUND:There is heterogeneity in the literature regarding the anatomy and number of ligamentous bands that form the deltoid ligament (DL). Anatomic knowledge of the DL and its variations are important for surgeons who repair ankle fractures. METHODS:The DL was dissected in 33 ankles from 17 formalin-fixed cadavers (mean age at death, 76.6 years) to examine its morphology. The length, width, and thickness of its constituent bands were recorded with a digital caliper. Descriptive and correlational statistics were used to investigate the relationships between band size, age at death, and sex. A literature review was conducted to compare our data to those of previous studies. RESULTS:The DL has superficial and deep layers with up to 8 different bands. CONCLUSION:The DL stabilizes the medial ankle and should be evaluated in flatfoot deformities and severe ankle fractures. CLINICAL RELEVANCE:Anatomic knowledge of DL variations should aid the surgeon in repairing torn DLs. 10.1177/1071100714535766
Foot Pain and Morphofunctional Foot Disorders in Patients with Rheumatoid Arthritis: A Multicenter Cross-Sectional Study. Reina-Bueno María,Munuera-Martínez Pedro V,Pérez-García Sergio,Vázquez-Bautista María Del Carmen,Domínguez-Maldonado Gabriel,Palomo-Toucedo Inmaculada C International journal of environmental research and public health Foot problems are highly prevalent in people with rheumatoid arthritis. This study aims to explore the foot morphology, pain and function in rheumatoid arthritis patients and the relation with the time of disease debut. A cross-sectional study was designed. Footprint, the Foot Posture Index, the hallux valgus prevalence, foot pain and function in 66 rheumatoid arthritis patients and the association with time since diagnosis, were recorded. The Foot Function Index, the Manchester Foot Pain and Disability Index, the Visual Analogic Scale, and the Manchester Scale for hallux valgus were administered and analyzed in two groups, with less and more than 10 years of diagnosis of the disease. A high prevalence of pronated (right 36.8% and left 38.6%) and highly pronated (right 15.8% and left 15.8%) feet was observed, as well as an elevated percentage of low arched footprints (right 68.4 and left 66.7%) and hallux valgus (right 59.6% and left 54.4%). Hallux valgus prevalence, toe deformities and Foot Function Index (Functional limitation) factors were significantly associated with the time since RA diagnosed adjusted for the other factors. The adjusted odds ratio of Hallux valgus prevalence was 4.9 (1.2-19.7). In addition, the foot function was diminished, and foot pain was present in most participants. In conclusion, rheumatoid arthritis patients' feet showed altered morphology and function, and with longer rheumatoid arthritis history, metatarsophalangical stability and foot function, but not pain and global foot posture, were likely to deteriorate. 10.3390/ijerph18095042
The Foot and Ankle Kinematics of a Simulated Progressive Collapsing Foot Deformity During Stance Phase: A Cadaveric Study. Foot & ankle international BACKGROUND:Progressive collapsing foot deformity (PCFD) is a complex pathology associated with tendon insufficiency, ligamentous failure, joint malalignment, and aberrant plantar force distribution. Existing knowledge of PCFD consists of static measurements, which provide information about structure but little about foot and ankle kinematics during gait. A model of PCFD was simulated in cadavers (sPCFD) to quantify the difference in joint kinematics and plantar pressure between the intact and sPCFD conditions during simulated stance phase of gait. METHODS:In 12 cadaveric foot and ankle specimens, the sPCFD condition was created via sectioning of the spring ligament and the medial talonavicular joint capsule followed by cyclic axial compression. Specimens were then analyzed in intact and sPCFD conditions via a robotic gait simulator, using actuators to control the extrinsic tendons and a rotating force plate underneath the specimen to mimic the stance phase of walking. Force plate position and muscle forces were optimized using a fuzzy logic iterative process to converge and simulate in vivo ground reaction forces. An 8-camera motion capture system recorded the positions of markers fixed to bones, which were then used to calculate joint kinematics, and a plantar pressure mat collected pressure distribution data. Joint kinematics and plantar pressures were compared between intact and sPCFD conditions. RESULTS:The sPCFD condition increased subtalar eversion in early, mid-, and late stance ( < .05), increased talonavicular abduction in mid- and late stance ( < .05), and increased ankle plantarflexion ( < .05), adduction ( < .05), and inversion ( < .05). The center of plantar pressure was significantly ( < .01) medialized in this model of sPCFD and simulated stance phase of gait. DISCUSSION:Subtalar and talonavicular joint kinematics and plantar pressure distribution significantly changed with the sPCFD and in the directions expected from a PCFD foot. We also found that ankle joint kinematics changed with medial and plantar drift of the talar head, indicating abnormal talar rotation. Although comparison to an in vivo PCFD foot was not performed, this sPCFD model produced changes in foot kinematics and indicates that concomitant abnormal changes may occur at the ankle joint with PCFD. CLINICAL RELEVANCE:This study describes the dynamic kinematic and plantar pressure changes in a cadaveric model of simulated progressive collapsing foot deformity during simulated stance phase. 10.1177/10711007221126736
Finite Element Analysis of Generalized Ligament Laxity on the Deterioration of Hallux Valgus Deformity (Bunion). Frontiers in bioengineering and biotechnology Hallux valgus is a common foot problem affecting nearly one in every four adults. Generalized ligament laxity was proposed as the intrinsic cause or risk factor toward the development of the deformity which was difficult to be investigated by cohort clinical trials. Herein, we aimed to evaluate the isolated influence of generalized ligament laxity on the deterioration using computer simulation (finite element analysis). We reconstructed a computational foot model from a mild hallux valgus participant and conducted a gait analysis to drive the simulation of walking. Through parametric analysis, the stiffness of the ligaments was impoverished at different degrees to resemble different levels of generalized ligament laxity. Our simulation study reported that generalized ligament laxity deteriorated hallux valgus by impairing the load-bearing capacity of the first metatarsal, inducing higher deforming force, moment and malalignment at the first metatarsophalangeal joint. Besides, the deforming moment formed a deteriorating vicious cycle between hallux valgus and forefoot abduction and may result in secondary foot problems, such as flatfoot. However, the metatarsocuneiform joint did not show a worsening trend possibly due to the overriding forefoot abduction. Controlling the deforming load shall be prioritized over the correction of angles to mitigate deterioration or recurrence after surgery. 10.3389/fbioe.2020.571192
Evaluation and Management of Common Accessory Ossicles of the Foot and Ankle in Children and Adolescents. Murphy Robert F,Van Nortwick Sara S,Jones Richard,Mooney James F The Journal of the American Academy of Orthopaedic Surgeons Accessory ossicles are a common radiographic finding about the foot and ankle in children and adolescents. They are often noted incidentally during evaluation of foot and ankle injuries, and most can be managed nonsurgically. Although over 20 accessory ossicles have been described around the foot and ankle, five specific structures generate the most concern in pediatric patients. An accessory navicular presents commonly with medial midfoot pain and may require surgical intervention after failure of nonsurgical treatment. Although an accessory navicular can be treated surgically with simple excision, there is some recent evidence that supports concomitant reconstruction of associated flatfoot deformities. Os trigonum, an ossicle posterior to the talus, is also commonly asymptomatic. However, os trigonum may be associated with persistent posterior ankle pain, and open and endoscopic resection techniques are successful. Os subfibulare is an uncommon ossicle that may be associated with recurrent ankle sprains. Recent literature reports successful return to activities after ossicle excision and ligament reconstruction. Os subtibiale may be confused with a medial malleolar fracture in skeletally immature patients. Os peroneum may contribute to lateral midfoot pain. 10.5435/JAAOS-D-20-00218
Dynamic gait stability of treadmill versus overground walking in young adults. Yang Feng,King George A Journal of electromyography and kinesiology : official journal of the International Society of Electrophysiological Kinesiology Treadmill has been broadly used in laboratory and rehabilitation settings for the purpose of facilitating human locomotion analysis and gait training. The objective of this study was to determine whether dynamic gait stability differs or resembles between the two walking conditions (overground vs. treadmill) among young adults. Fifty-four healthy young adults (age: 23.9±4.7years) participated in this study. Each participant completed five trials of overground walking followed by five trials of treadmill walking at a self-selected speed while their full body kinematics were gathered by a motion capture system. The spatiotemporal gait parameters and dynamic gait stability were compared between the two walking conditions. The results revealed that participants adopted a "cautious gait" on the treadmill compared with over ground in response to the possible inherent challenges to balance imposed by treadmill walking. The cautious gait, which was achieved by walking slower with a shorter step length, less backward leaning trunk, shortened single stance phase, prolonged double stance phase, and more flatfoot landing, ensures the comparable dynamic stability between the two walking conditions. This study could provide insightful information about dynamic gait stability control during treadmill ambulation in young adults. 10.1016/j.jelekin.2016.09.004
Consensus on Indications for Isolated Subtalar Joint Fusion and Naviculocuneiform Fusions for Progressive Collapsing Foot Deformity. Foot & ankle international RECOMMENDATION:Peritalar subluxation represents an important hindfoot component of progressive collapsing foot deformity, which can be associated with a breakdown of the medial longitudinal arch. It results in a complex 3-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction, and pronation. Loss of peritalar stability allows the talus to rotate and translate on the calcaneal and navicular bone surfaces, typically moving medially and anteriorly, which may result in sinus tarsi and subfibular impingement. The onset of degenerative disease can manifest with stiffening of the subtalar (ST) joint and subsequent fixed and possibly arthritic deformity. While ST joint fusion may permit repositioning and stabilization of the talus on top of the calcaneus, it may not fully correct forefoot abduction and it does not correct forefoot varus. Such varus may be addressed by a talonavicular (TN) fusion or a plantar flexion osteotomy of the first ray, but, if too pronounced, it may be more effectively corrected with a naviculocuneiform (NC) fusion. The NC joint has a curvature in the sagittal plane. Thus, preserving the shape of the joint is the key to permitting plantarflexion correction by rotating the midfoot along the debrided surfaces and to fix it. Intraoperatively, care must be also taken to not overcorrect the talocalcaneal angle in the horizontal plane during the ST fusion (eg, to exceed the external rotation of the talus and inadvertently put the midfoot in a supinated position). Such overcorrection can lead to lateral column overload with persistent lateral midfoot pain and discomfort. A contraindication for an isolated ST fusion may be a rupture of posterior tibial tendon because of the resultant loss of the internal rotation force at the TN joint. In these cases, a flexor digitorum longus tendon transfer is added to the procedure. LEVEL OF EVIDENCE:Level V, consensus, expert opinion. 10.1177/1071100720950738
Incidence and predictors of valgus tibiotalar tilt after progressive collapsing foot deformity reconstruction using subtalar fusion with concomitant procedures. Archives of orthopaedic and trauma surgery PURPOSE:Development of valgus tibiotalar tilt is a significant complication after subtalar fusion for progressive collapsing foot deformity (PCFD) correction. However, its incidence and etiologic factors have not been extensively studied. The purpose of this study was to define the incidence of valgus tibiotalar tilt after subtalar fusion for PCFD reconstruction, and to determine predictors of this complication. METHODS:This study included 59 patients who underwent PCFD reconstruction with subtalar fusion. Patients with tibiotalar tilt prior to surgery were excluded. On standard weightbearing radiographs, the talonavicular coverage angle, talo-1st metatarsal angle, calcaneal pitch, hindfoot moment arm (HMA), and medial distal tibial angle were measured. Weightbearing computed tomography (WBCT) was used to determine the presence of lateral bony impingement. A radiologist evaluated the superficial and deep deltoid ligaments using magnetic resonance imaging (MRI). Univariate regression analysis was used to identify the factors associated with development of postoperative valgus tibiotalar tilt, defined as tilt > 2 degrees. RESULTS:Seventeen patients (28.8%) developed postoperative valgus tibiotalar tilt at a mean of 7.7 (range 2-31) months. Eight (47.1%) of these patients developed valgus tibiotalar tilt within 3 months. Univariate logistic regression demonstrated association between preoperative HMA and postoperative valgus tibiotalar tilt (odds ratio 1.06, P = 0.026), with a 6% increase in risk per millimeter of increased HMA. Deltoid ligament status and concomitant procedures on other joints did not correlate with postoperative valgus tilt. CONCLUSION:Our findings indicate that surgeons should be cognizant of patients with a greater degree of preoperative hindfoot valgus and their propensity to develop a valgus ankle deformity. Additionally, our relatively high incidence of valgus tibiotalar tilt suggests that weightbearing ankle radiographs should be included in the initial and subsequent follow-up of PCFD patients with hindfoot valgus treated with subtalar fusion. 10.1007/s00402-023-04906-x
Foot posture is associated with morphometry of the peroneus longus muscle, tibialis anterior tendon, and Achilles tendon. Murley G S,Tan J M,Edwards R M,De Luca J,Munteanu S E,Cook J L Scandinavian journal of medicine & science in sports The aim of this study was to investigate the association between foot type and the morphometry of selected muscles and tendons of the lower limb. Sixty-one healthy participants (31 male, 30 female; aged 27.1 ± 8.8 years) underwent gray-scale musculoskeletal ultrasound examination to determine the anterior-posterior (AP) thickness of tibialis anterior, tibialis posterior, and peroneus longus muscles and tendons as well as the Achilles tendon. Foot type was classified based on arch height and footprint measurements. Potentially confounding variables (height, weight, hip and waist circumference, rearfoot and ankle joint range of motion, and levels of physical activity) were also measured. Multiple linear regression models were used to determine the association between foot type with muscle and tendon morphometry accounting for potentially confounding variables. Foot type was significantly and independently associated with AP thickness of the tibialis anterior tendon, peroneus longus muscle, and Achilles tendon, accounting for approximately 7% to 16% of the variation. Flat-arched feet were associated with a thicker tibialis anterior tendon, a thicker peroneus longus muscle, and a thinner Achilles tendon. Foot type is associated with morphometry of tendons that control sagittal plane motion of the rearfoot; and the peroneus longus muscle that controls frontal plane motion of the rearfoot. These findings may be related to differences in tendon loading during gait. 10.1111/sms.12025
Biomechanical results of percutaneous calcaneal osteotomy using two different osteotomy designs. Gutteck N,Haase K,Kielstein H,Delank K S,Arnold Ch Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Percutaneous osteotomy of calcaneus has been proposed to reduce the complication rate and became more and more popular. The bone cut can be performed as a straight or chevron-like (V) osteotomy using a Shannon burr. Comparative studies of straight or V-osteotomy as like as one or two screws in percutaneous calcaneal osteotomies are missing in the literature. We hypothesize that the V-osteotomy will result in a higher stiffness in biomechanical testing as the straight osteotomy using single screw for fixation. METHODS:The straight osteotomy (9 fresh-frozen specimens) and V-osteotomy (9 fresh-frozen specimens) was performed and the calcaneal tuberosity was moved 10mm medially and slightly rotated. One 6,5mm cancellous compression screw was used for osteosynthesis. Specimens were preconditioned with 100N over 100 cycles. The force was increased after every 100N by 100N from 200 to 500N. This was followed by cyclic loading with 600N for 500 cycles. RESULTS:Despite the higher mean values of the group with V-osteotomy, no significant difference was registered between the two groups regarding the stiffness at all force levels. A higher failure rate was observed in the group with straight osteotomy. CONCLUSION:The moderate correlation of bone density and stiffness in the V-group, and significantly lower failure rate with no secondary dislocation in fluoroscopy indicates the superiority of the V-osteotomy in the present study. Whether the demonstrated advantages can be reflected in clinical practice should be investigated in further studies. LEVEL OF CLINICAL EVIDENCE:5. 10.1016/j.fas.2019.07.004
The association between foot alignment and the development of ingrown toenails: A case-control study in a young adult military population. Kim Jaeyoung,Kim Kyungho,Kwon Minsoo,Cho Jaeho,Seilern Und Aspang Jesse Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:This case-control study aimed to explore an association between foot alignment and development and presentation of the ingrown toenail. METHODS:Radiographs were evaluated for hallux interphalangeal angle (HIA), hallux valgus angle (HVA), talonavicular coverage angle (TNC), talo-first metatarsal (Meary's) angle, and calcaneal pitch angle (CP), as well as medial sesamoid position in a cohort of 103 young and healthy patients (mean age of 20.5 years) with ingrown toenails. A control group of 63 patients was included, and the radiographic parameters were compared. Subgroup analysis was performed in patients with lateral (n = 65) or medial (n = 38) nail fold involvement. RESULTS:The overall study group demonstrated a larger TNC and Meary's angle and smaller CP than the control group, while no significant difference was found regarding the HIA and HVA. The lateral nail fold group had a larger HIA when compared to the medial nail fold group. Multiple regression analysis revealed that for ingrown toenail development, the only risk factor was a decrease in the CP. In the case of lateral nail fold involvement, an increase in the HIA found to be the only factor. CONCLUSION:A lower medial longitudinal arch seems to be a predisposing factor in developing an ingrown toenail. The lateral nail fold involvement was associated with lateral deviation of the distal phalanx. The result of this study could provide information on prevention, treatment, recurrence, and patient counseling of an ingrown toenail in otherwise young and healthy individuals. 10.1016/j.fas.2021.02.007
Biometry of the calcaneocuboid joint: biomechanical implications. Bonnel F,Teissier P,Colombier J A,Toullec E,Assi C Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons Precise biometric data of calcaneus, cuboid bones and calcaneocuboid joint are not alluded to in textbooks of anatomy. This study focussed on the biometry of 50 calcanei, 30 cuboid dry bones, and anatomical specimens of 21 transverse tarsal joints. Measurement of the length, width, angular orientation, contact surface and radius of curvature, rolling band of the joints surfaces according to the main axes were performed. The results focussed on biometric variations with several morphological types never identified previously. Measurements obtained on dry bones and anatomical specimens with the functions of ligaments were distinguished. The morphology of the calcaneus could explain the results of osteotomy procedures for the treatment of adult flatfoot. A better knowledge of the joint surfaces and biometric data would generate a modeling of the calcaneocuboid joint and function in locking the transverse tarsal joint. 10.1016/j.fas.2012.12.001
Consensus on Indications for Medial Cuneiform Opening Wedge (Cotton) Osteotomy in the Treatment of Progressive Collapsing Foot Deformity. Foot & ankle international RECOMMENDATION:Forefoot varus is a physical and radiographic examination finding associated with the Progressive Collapsing Foot Deformity (PCFD). Varus position of the forefoot relative to the hindfoot is caused by medial midfoot collapse with apex plantar angulation of the medial column. Some surgeons use the term to describe this same deformity (see Introduction section with nomenclature). Correction of this deformity is important to restore the weightbearing tripod of the foot and help resist a recurrence of foot collapse. When the forefoot varus deformity is isolated to the medial metatarsal and medial cuneiform, correction is indicated with an opening wedge medial cuneiform (Cotton) osteotomy, typically with interposition of an allograft bone wedge from 5 to 11 mm in width at the base. When the forefoot varus is global, involving varus angulation of the entire forefoot and midfoot relative to the hindfoot, other procedures are needed to adequately correct the deformity. LEVEL OF EVIDENCE:Level V, consensus, expert opinion. 10.1177/1071100720950739
Influence of tibialis posterior muscle activation on foot anatomy under axial loading: A biomechanical CT human cadaveric study. Dullaert Koen,Hagen Jennifer E,Simons Paul,Gras Florian,Gueorguiev Boyko,Richards R Geoff,Klos Kajetan Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Collapse of the medial longitudinal arch and subluxation of the subtalar joint are common occurrences in adult flatfoot deformity. Controversy exists about the role of the tibialis posterior (TP) tendon as first and/or essential lesion. Subtle changes in the foot configuration can occur under weight bearing. PURPOSE:This human cadaveric study is designed to investigate the effect that isolated actuation of the TP tendon has on the medial longitudinal arch and the hindfoot configuration under simulated weight bearing. METHODS:A radiolucent frame was developed to apply axial loading on cadaveric lower legs during computer tomography (CT) examinations. Eight pairs of fresh-frozen specimens were imaged in neutral position under foot-flat loading (75N) and under single-leg stance weight bearing (700N) without and with addition of 150N pulling force on the TP tendon. Measurements of subtalar joint subluxation, forefoot arch angle and talo-first metatarsal angle were conducted on each set of CT scans. RESULTS:Subtalar subluxation, talo-first metatarsal angle and talo-navicular coverage angle significantly increased under single-leg stance weight bearing, whereas forefoot arch angle significantly decreased. Actuation of the TP tendon under weight bearing did not restore the forefoot arch angle or correct subtalar subluxation and talo-metatarsal angle. CONCLUSION:Significant effect that weight bearing has on the medial longitudinal arch and the subtalar joint configuration is demonstrated in an ex-vivo model. In absence of other medial column derangement, actuation of the TP tendon alone does not seem to reconstitute the integrity of the medial longitudinal arch or correct the hindfoot subluxation under weight bearing. CLINICAL RELEVANCE:The findings of this study together with the developed model for ex-vivo investigation provide a further insight in foot anatomy. 10.1016/j.fas.2016.07.003
Dynamic effect of the tibialis posterior muscle on the arch of the foot during cyclic axial loading. Kamiya Tomoaki,Uchiyama Eiichi,Watanabe Kota,Suzuki Daisuke,Fujimiya Mineko,Yamashita Toshihiko Clinical biomechanics (Bristol, Avon) BACKGROUND:The most common cause of acquired flatfoot deformity is tibialis posterior tendon dysfunction. The present study compared the change in medial longitudinal arch height during cyclic axial loading with and without activated tibialis posterior tendon force. METHODS:Fourteen normal, fresh frozen cadaveric legs were used. A total of 10,000 cyclic axial loadings of 500 N were applied to the longitudinal axis of the tibia. The 32-N tibialis posterior tendon forces were applied to the specimens of the active group (n=7). Specimens of another group (non-active group, n=7) were investigated without the tibialis posterior tendon force. The bony arch index was calculated from the displacement of the navicular height. FINDINGS:The mean initial bony arch indexes with maximal weightbearing were 0.239 (SD 0.009) in active group and 0.239 (SD 0.014) in non-active group. After 7000 cycles, the bony arch indexes with maximal weightbearing were significantly greater in the active group (mean 0.214, SD 0.013) than in the non-active group (mean 0.199, SD 0.013). The mean bony arch indexes with maximal weightbearing after 10,000 cycles were 0.212 (SD 0.011) in the active group and 0.196 (SD 0.015) in the non-active group. INTERPRETATION:The passive supportive structures were inadequate, and the tibialis posterior muscle was essential to maintain the medial longitudinal arch of the foot in the dynamic weightbearing condition. The findings underscore that physical therapy and arch supportive equipments are important to prevent flatfoot deformity in the condition of weakness or dysfunction of the tibialis posterior muscle. 10.1016/j.clinbiomech.2012.06.006
Distal Tibiofibular Syndesmotic Widening in Progressive Collapsing Foot Deformity. Foot & ankle international BACKGROUND:Lateral overload in progressive collapsing foot deformity (PCFD) takes place as hindfoot valgus, peritalar subluxation, and valgus instability of the ankle increase. Fibular strain due to chronic lateral impingement may lead to distraction forces over the distal tibiofibular syndesmosis (DTFS). This study aimed to assess and correlate the severity of the foot and ankle offset (FAO) as a marker of progressive PCFD with the amount of DTFS widening and to compare it to controls. METHODS:In this case-control study, 62 symptomatic patients with PCFD and 29 controls who underwent standing weightbearing computed tomography (WBCT) examination were included. Two fellowship-trained blinded orthopedic foot and ankle surgeons performed FAO (%) and DTFS area measurements (mm). DTFS was assessed semiautomatically on axial-plane WBCT images, 1 cm proximal to the apex of the tibial plafond. Values were compared between patients with PCFD and controls, and Spearman correlation between FAO and DTFS area measurements was assessed. values of less than .05 were considered significant. RESULTS:Patients with PCFD demonstrated significantly increased FAO and DTFS measurements in comparison to controls. A mean difference of 6.9% ( < .001) in FAO and 10.4 mm ( = .026) in DTFS was observed. A significant but weak correlation was identified between the variables, with a Þ of 0.22 ( = .03). A partition predictive model demonstrated that DTFS area measurements were highest when FAO values were between 7% and 9.3%, with mean (SD) values of 92.7 (22.4) mm. CONCLUSION:To our knowledge, this was the first study to assess syndesmotic widening in patients with PCFD. We found patients with PCFD to demonstrate increased DTFS area measurements compared to controls, with a mean difference of approximately 10 mm. A significantly weak positive correlation was found between FAO and DTFS area measurements, with the highest syndesmotic widening occurring when FAO values were between 7% and 9.3%. Our study findings suggest that chronic lateral impingement in patients with PCFD can result in a negative biomechanical impact on syndesmotic alignment, with increased DTFS stress and subsequent widening. LEVEL OF EVIDENCE:Level III, retrospective comparative study. 10.1177/1071100720982907
Biomechanical Characteristics of the Support Leg During Side-Foot Kicking in Soccer Players With Chronic Ankle Instability. Orthopaedic journal of sports medicine Background:Chronic ankle instability (CAI) in soccer players can increase the risk of recurrent ankle varus sprains and damage the articular surface of the ankle joint, thus increasing the risk of osteoarthritis. It is important to understand the biomechanical characteristics of the support leg during kicking in soccer players with CAI. Purpose/Hypothesis:The purpose of this study was to clarify the kinematics of the kicking motion of soccer players with CAI. It was hypothesized that at the point before ball contact when the support leg makes flat-foot contact with the ground, soccer players with CAI will land with ankle inversion in the support leg during a side-foot kick compared with players without CAI. Study Design:Controlled laboratory study. Methods:The study cohort included 19 male college soccer players (mean age, 20.5 ± 0.9 years) with greater than 8 years of soccer experience who were recruited from August 2019 to March 2020. Of these athletes, 10 had CAI and 9 had no CAI in the support leg, as diagnosed according to the Cumberland Ankle Instability Tool. Kinematic data for the trunk, hip, knee, and foot of the support leg during a side-foot kick were obtained using a 3-dimensional, motion-analysis system. The Mann-Whitney test or Student test was selected to identify differences in variables between the CAI and non-CAI groups. Results:There were no significant differences in physical characteristics between the CAI and non-CAI groups. At the point when the support leg made flat-foot contact with the ground, the players with CAI had more eversion of the hindfoot with respect to the tibia (-28.3° ± 12.1° vs -13.9° ± 14.2°; = .03), a more varus alignment of the knee (26.0° ± 10.7° vs 13.7° ± 10.5°; = .03), and a lower arch height index (0.210 ± 0.161 vs 0.233 ± 0.214; = .046) compared with non-CAI players. Conclusion:Significant differences between players with and without CAI were seen in the support leg kinematics at flat-foot contact with the ground during the kicking cycle. Clinical Relevance:The biomechanical alignment of the support leg during a side-foot kick in players with CAI may reflect a subconscious attempt to avoid inversion of the foot and further ankle sprains. 10.1177/23259671221112966
A New Anatomical Classification for Tibialis Posterior Tendon Insertion and Its Clinical Implications: A Cadaveric Study. Park Jeong-Hyun,Kim Digud,Kwon Hyung-Wook,Lee Mijeong,Choi Yu-Jin,Park Kwang-Rak,Youn Kwan Hyun,Cho Jaeho Diagnostics (Basel, Switzerland) The variations in the tibialis posterior tendon (TPT) could not be defined by previous classification; thus, this study used a larger-scale cadaver with the aim to classify the types of TPT insertion based on the combination of the number and location of TPT insertions. A total of 118 feet from adult formalin-fixed cadavers were dissected (68 males, 50 females). The morphological characteristics and measurements of TPT insertion were evaluated. Four types of TPT insertions were classified, wherein the most common type was type 4 (quadruple insertions, 78 feet, 66.1%), which was divided into four new subtypes that were not defined in the previous classification. The second most common type was type 3 (triple insertions, 25 feet, 21.2%) with three subtypes, including the new subtype. Type 2 was found in 13 feet (11%), and the rarest type was type 1 (2 feet, 1.7%), wherein the main tendon was only attached to the navicular bone and the medial cuneiform bone. We suggest high morphological variability of the TPT in relation to the insertion location, along with the possibility of significant differences according to race and gender. Moreover, this classification will help clinicians understand adult flatfoot deformity-related posterior tibial tendon dysfunction (PTTD). 10.3390/diagnostics11091619
The Effects of the Short Foot Exercise on Navicular Drop: A Critically Appraised Topic. Haun Cameron,Brown Cathleen N,Hannigan Kimberly,Johnson Samuel T Journal of sport rehabilitation Clinical Scenario: Deformation of the arch, as measured by navicular drop (ND), is linked to lower-extremity musculoskeletal injuries. The short foot exercise (SFE) has been used to strengthen the intrinsic foot muscles that support the arch. Clinical Question: Does the SFE decrease ND in healthy adults? Summary of Key Findings: Three studies that examined the use of the SFE on ND were included. A randomized control trial that compared the SFE to a towel-curl exercise and a control group found no significant differences between the 3 groups. A randomized control trial compared the SFE to the use of arch support insoles in individuals with a flexible flatfoot and found a significant improvement in the SFE group. A prospective cohort study, without a control group, reported a significant decrease in ND following a 4-week SFE intervention without a regression at an 8-week follow-up. Overall, two of the three studies reported a significant reduction in ND following an SFE. Clinical Bottom Line: There is preliminary data supporting the use of the SFE to decrease ND-particularly in individuals with a flexible flatfoot. However, issues with the study designs make it difficult to interpret the data. Strength of Recommendation: Due to limited evidence, there is grade B evidence to support the use of the SFE to decrease ND. 10.1123/jsr.2019-0437
Adult Acquired Flatfoot Deformity: A Narrative Review about Imaging Findings. Diagnostics (Basel, Switzerland) Adult acquired flatfoot deformity (AAFD) is a disorder caused by repetitive overloading, which leads to progressive posterior tibialis tendon (PTT) insufficiency. It mainly affects middle-aged women and occurs with foot pain, malalignment, and loss of function. After clinical examination, imaging plays a key role in the diagnosis and management of this pathology. Imaging allows confirmation of the diagnosis, monitoring of the disorder, outcome assessment and complication identification. Weight-bearing radiography of the foot and ankle are gold standard for the diagnosis of AAFD. Magnetic Resonance Imaging (MRI) is not routinely needed for the diagnosis; however, it can be used to evaluate the spring ligament and the degree of PTT damage which can help to guide surgical plans and management in patients with severe deformity. Ultrasonography (US) can be considered another helpful tool to evaluate the condition of the PTT and other soft-tissue structures. Computed Tomography (CT) provides enhanced, detailed visualization of the hindfoot, and it is useful both in the evaluation of bone abnormalities and in the accurate evaluation of measurements useful for diagnosis and post-surgical follow-up. Other state-of-the-art imaging examinations, like multiplanar weight-bearing imaging, are emerging as techniques for diagnosis and preoperative planning but are not yet standardized and their scope of application is not yet well defined. The aim of this review, performed through Pubmed and Web of Science databases, was to analyze the literature relating to the role of imaging in the diagnosis and treatment of AAFD. 10.3390/diagnostics13020225
Adult-Acquired Flatfoot Deformity: Combined Talonavicular Arthrodesis and Calcaneal Displacement Osteotomy versus Double Arthrodesis. Fischer Sebastian,Oepping Julia,Altmeppen Jan,Gramlich Yves,Neun Oliver,Manegold Sebastian,Hoffmann Reinhard Journal of clinical medicine BACKGROUND:Adult-acquired flatfoot deformity due to posterior tibial tendon dysfunction (PTTD) is one of the most common foot deformities among adults. HYPOTHESIS:Our study aimed to confirm that the combined procedures of calcaneal displacement osteotomy and talonavicular arthrodesis are equivalent to double arthrodesis. METHODS:Between 2016 and 2020, 41 patients (13 male and 28 females, mean age of 63 years) were retrospectively enrolled in the comparative study. All deformities were classified into Stages II and III of PTTD, according to Johnson and Strom. All patients underwent isolated bony realignment of the deformity: group A ( = 19) underwent calcaneal displacement osteotomy and talonavicular arthrodesis, and group B ( = 23) underwent double arthrodesis. Measurements from the Foot Function Index-D (FFI-D) and the SF-12 questionnaire were collected, with a comparison of pre- and post-operative radiographs conducted. The mean follow-up period for patients was 3.4 years. RESULTS:The mean FFI-D was 33.9 (group A: 34.5; group B: 33.5), the mean SF-12 physical component summary was 43.13 (group A: 40.9; group B: 44.9), and the mean SF-12 mental component summary was 43.13 (group A: 40.9; group B: 44.9). The clinical data and corrected angles showed no significant intergroup differences. CONCLUSION:Based on the available data, our study confirmed that the combined procedures of talonavicular arthrodesis and calcaneal shift, with preservation of the subtalar joint, can be considered equivalent to the established double arthrodesis, with no significant differences in terms of clinical and radiological outcomes. 10.3390/jcm11030840
A Three-Dimensional Printed Foot Orthosis for Flexible Flatfoot: An Exploratory Biomechanical Study on Arch Support Reinforcement and Undercut. Materials (Basel, Switzerland) The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification features (arch stiffness and arch height) using three sets of customized 3D-printed arch support insoles (R+U+, R+U-, and R-U+). The arch support stiffness could be with or without reinforcement (R+/-) and the arch height may or may not have an additional elevation, undercutting (U+/-), which were compared to the control (no insole). Ten collegiate participants (four males and six females) with flexible flatfoot were recruited for gait analysis on foot kinematics, vertical ground reaction force, and plantar pressure parameters. A randomized crossover trial was conducted on the four conditions and analyzed using the Friedman test with pairwise Wilcoxon signed-rank test. Compared to the control, there were significant increases in peak ankle dorsiflexion and peak pressure at the medial midfoot region, accompanied by a significant reduction in peak pressure at the hindfoot region for the insole conditions. In addition, the insoles tended to control hindfoot eversion and forefoot abduction though the effects were not significant. An insole with stronger support features (R+U+) did not necessarily produce more favorable outcomes, probably due to over-cutting or impingement. The outcome of this study provides additional data to assist the design rectification process. Future studies should consider a larger sample size with stratified flatfoot features and covariating ankle flexibility while incorporating more design features, particularly medial insole postings. 10.3390/ma14185297
Automated diagnosis of flatfoot using cascaded convolutional neural network for angle measurements in weight-bearing lateral radiographs. European radiology OBJECTIVES:Diagnosis of flatfoot using a radiograph is subject to intra- and inter-observer variabilities. Here, we developed a cascade convolutional neural network (CNN)-based deep learning model (DLM) for an automated angle measurement for flatfoot diagnosis using landmark detection. METHODS:We used 1200 weight-bearing lateral foot radiographs from young adult Korean males for the model development. An experienced orthopedic surgeon identified 22 radiographic landmarks and measured three angles for flatfoot diagnosis that served as the ground truth (GT). Another orthopedic surgeon (OS) and a general physician (GP) independently identified the landmarks of the test dataset and measured the angles using the same method. External validation was performed using 100 and 17 radiographs acquired from a tertiary referral center and a public database, respectively. RESULTS:The DLM showed smaller absolute average errors from the GT for the three angle measurements for flatfoot diagnosis compared with both human observers. Under the guidance of the DLM, the average errors of observers OS and GP decreased from 2.35° ± 3.01° to 1.55° ± 2.09° and from 1.99° ± 2.76° to 1.56° ± 2.19°, respectively (both p < 0.001). The total measurement time decreased from 195 to 135 min in observer OS and from 205 to 155 min in observer GP. The absolute average errors of the DLM in the external validation sets were similar or superior to those of human observers in the original test dataset. CONCLUSIONS:Our CNN model had significantly better accuracy and reliability than human observers in diagnosing flatfoot, and notably improved the accuracy and reliability of human observers. KEY POINTS:• Development of deep learning model (DLM) that allows automated angle measurements for landmark detection based on 1200 weight-bearing lateral radiographs for diagnosing flatfoot. • Our DLM showed smaller absolute average errors for flatfoot diagnosis compared with two human observers. • Under the guidance of the model, the average errors of two human observers decreased and total measurement time also decreased from 195 to 135 min and from 205 to 155 min. 10.1007/s00330-023-09442-1
Obesity and falls in older women: Mediating effects of muscle quality, foot loads and postural control. Neri Silvia G R,Harvey Lara A,Tiedemann Anne,Gadelha André B,Lima Ricardo M Gait & posture BACKGROUND:Obesity is associated with an increased risk of falls in older women. However, it is not certain whether factors commonly associated with obesity and falls mediate this risk. RESEARCH QUESTION:Do lower-limb muscle quality, foot loads and postural control mediate the relationship between obesity and falls in women aged 60 years and older? METHODS:At baseline, 246 female participants underwent obesity screening (BMI≥30 kg/m²), and measurements of muscle quality (isokinetic dynamometer and dual-energy X-ray absorptiometry), foot loads (pressure platform) and postural balance (force platform). Incident falls were recorded at the end of the 18-month follow-up period via participant recall. To test whether, and to what extent, biomechanical factors mediated the relationship between obesity and falls, the Natural Indirect Effects (NIE), Natural Direct Effect (NDE) and proportion mediated were calculated using the counterfactual approach. Significance level was set at p < .05. RESULTS:204 participants (83 %) completed the follow-up. As expected, obesity was associated with a higher risk of being a faller (RR: 2.13, 95 % CI: 1.39-3.27). Using the counterfactual approach, only specific torque (NIE: 1.11, 95 % CI: 1.01-1.38) and flatfoot (NIE: 1.10, 95 % CI: 1.01-1.32) were significant mediators of the relationship between obesity and falls. Specific torque and flatfoot mediated 19 % and 21 % of the relationship, respectively. SIGNIFICANCE:Lower-limb muscle quality (specific torque) and foot loads (flatfoot) mediate the relationship between obesity and falls in older women. The inclusion of muscle strengthening and podiatry interventions as part of a fall prevention program may benefit this population. 10.1016/j.gaitpost.2020.01.025
The combined effect of short foot exercises and orthosis in symptomatic flexible flatfoot: a randomized controlled trial. European journal of physical and rehabilitation medicine BACKGROUND:Flatfoot is a musculoskeletal problem associated with dysfunctional active and passive supporting structures of the normal foot curvature. Strengthening of the intrinsic foot muscles or using shoe orthosis are recommend treatment approaches. However, investigating the effect of combining both approaches is still warranted. AIM:To examine the effect of applying short foot exercises (SFE) combined with shoe insole versus shoe insole alone on foot pressure measures, pain, function and navicular drop in individuals with symptomatic flexible flatfoot. DESIGN:Prospective, active control, parallel-group, assessor-blinded, randomized controlled trial and intention-to-treat analysis. SETTING:Outpatient physical therapy clinic of a university teaching hospital. POPULATION:Forty participants with symptomatic flexible flatfoot. METHODS:A six-week treatment protocol of SFE (three sets of 10 repetitions a day) in addition to shoe insole (eight hours a day) (experimental group, N.=20) or shoe insole only (eight hours a day) (control group, N.=20). Clinic visits were made at baseline and every two weeks for monitoring and follow-up. The static and dynamic foot area, force and pressure measures, pain, lower extremity function, and navicular drop were assessed at baseline and postintervention. RESULTS:Forty participants joined the study and 37 (92.5%) completed the six-week intervention period. Foot pressure, pain and function showed a significant interaction (P=0.02 - <0.001) and time (P<0.001) effects with a non-significant group effect in favor of the experimental group. Post-hoc analysis revealed that the experimental group had lesser pain (P=0.002) and better function (P=0.03) than the control group at six weeks. Navicular drop decreased equally in both groups. CONCLUSIONS:Implementation of shoe insole and SFE for six weeks improved pain and function and altered foot pressure distribution greater than shoe insole alone in patients with symptomatic flatfoot. CLINICAL REHABILITATION IMPACT:Wearing shoe insole is an easy, but passive, treatment approach for a flatfoot problem. This study provided evidence regarding the added benefit of SFE. It is recommended that rehabilitation practitioners implement a comprehensive treatment protocol including both shoe insole and SFE for at least six weeks to achieve better results for their flatfoot patients. 10.23736/S1973-9087.23.07846-2
Diagnostic Accuracy of Various Radiological Measurements in the Evaluation and Differentiation of Flatfoot: A Cross-Sectional Study. Diagnostics (Basel, Switzerland) Arch angle is used to indicate flatfoot, but in some cases, it is not easily defined. The presence of flatfoot deformity remains difficult to diagnose due to a lack of reliable radiographic assessment tools. Although various assessment methods for flatfoot have been proposed, there is insufficient evidence to prove the diagnostic accuracy of the various tools. The main purpose of the study was to determine the best radiographic measures for flatfoot concerning the arch angle. Fifty-two feet radiographs from thirty-two healthy young females were obtained. Five angles and one index were measured using weight-bearing lateral radiographs; including arch angle, calcaneal pitch (CP), talar-first metatarsal angle (TFM), lateral talar angle (LTA), talar inclination angle (TIA) and navicular index (NI). Receiver-operating characteristics were generated to evaluate the flatfoot diagnostic accuracy for all radiographic indicators and Matthews correlation coefficient was calculated to determine the cutoff value for each measure. The strongest correlation was between arch angle and CP angle [r = -0.91, ≤ 0.0001, 95% confidence interval (CI) (from -0.94 to -0.84)]. Also, significant correlations were found between arch angle and NI [r = 0.62, ≤ 0.0001, 95% CI (0.42 to 0.76)], and TFM [r = 0.50, ≤ 0.0001, 95% CI (from 0.266 to 0.68)]. Furthermore, CP (cutoff, 12.40) had the highest accuracy level with value of 100% sensitivity and specificity followed by NI, having 82% sensitivity and 89% specificity for the cutoff value of 9.90. In conclusion, CP angle is inversely correlated with arch angle and considered a significant indicator of flatfoot. Also, the NI is easy to define radiographically and could be used to differentiate flat from normal arched foot among young adults. 10.3390/diagnostics12102288
Analysis of skeletal characteristics of flat feet using three-dimensional foot scanner and digital footprint. Biomedical engineering online BACKGROUND:Flat feet increase the risk of knee osteoarthritis and contribute to frailty, which may lead to worse life prognoses. The influence of the foot skeletal structure on flat feet is not yet entirely understood. Footprints are often used to evaluate feet. However, footprint-based measurements do not reflect the underlying structures of feet and are easily confounded by soft tissue. Three-dimensional evaluation of the foot shape can reveal the characteristics of flat feet. Therefore, foot shape evaluations have garnered increasing research interest. This study aimed to determine the correlation between the three-dimensional (3D) features of the foot and the measurement results of footprint and to predict the evaluation results of flat feet from the footprint based on the 3D features. Finally, the three-dimensional characteristics of flat feet, which cannot be revealed by footprint, were determined. METHODS:A total of 403 individuals (40-89 years) participated in this study. The proposed system was developed to identify seven skeletal features that were expected to be associated with flat feet. The loads on the soles of the feet were measured in a static standing position and with a digital footprint device. Specifically, two footprint indices were calculated: the Chippaux-Smirak index (CSI) and the Staheli index (SI). In the analysis, comparisons between male and female measurement variables were performed using the Student's t test. The relationships between the 3D foot features and footprint index parameters were determined by employing the Pearson correlation coefficient. Multiple linear regression was utilized to identify 3D foot features that were strongly associated with the CSI and SI. Foot features identified as significant in the multivariate regression analysis were compared based on a one-way analysis of variance (ANOVA) with Tukey's post hoc test. RESULTS:The CSI and SI were highly correlated with the instep height (IH) and navicular height (NH) of the 3D foot scanning system and were also derived from multiple regression analysis. In addition to the NH and IH, the indicators of the forefoot, transverse arch width, and transverse arch height were considered. In the flat foot group with CSI values above 62.7%, NH was 13.5% (p < 0.001) for males and 14.9% (p = 0.01) for females, and the axis of the bone distance was 5.3% (p = 0.05) for males and 4.9% (p = 0.10) for females. In particular, for CSI values above 62.7% and NH values below 13%, the axis of the bone distance was large and the foot skeleton was deformed. CONCLUSIONS:Decreased navicular bone height could be evaluated with the 3D foot scanning system even when flat feet were not detected from the footprint. The results indicate that the use of quantitative indices for 3D foot measurements is important when evaluating the flattening of the foot. Trial registration number UMIN000037694. Name of the registry: University Hospital Medical Information Network Registry. Date of registration: August 15, 2019. 10.1186/s12938-022-01021-7
The biomechanical effects of 3D printed and traditionally made foot orthoses in individuals with unilateral plantar fasciopathy and flat feet. Gait & posture BACKGROUND:Foot orthoses (FOs) are used to manage foot pathologies such as plantar fasciopathy. 3D printed custom-made FOs are increasingly being manufactured. Although these 3D-printed FOs look like traditionally heat-moulded FOs, there are few studies comparing FOs made using these two different manufacturing processes. RESEARCH QUESTION:How effective are 3D-printed FOs (3D-Print) compared to traditionally-made (Traditional) or no FOs (Control), in changing biomechanical parameters of flat-footed individuals with unilateral plantar fasciopathy? METHODS:Thirteen participants with unilateral plantar fasciopathy walked with shoes under three conditions: Control, 3D-print, and Traditional. 2 × 3 repeated measures analysis of variance (ANOVAs) with Bonferroni post-hoc tests were used to compare discrete kinematic and kinetic variables between limbs and conditions. Waveform analyses were also conducted using statistical parametric mapping (SPM). RESULTS:There was a significant condition main effect for arch height drop (p = 0.01; ηp =0.54). There was 0.87 mm (95% CI [-1.84, -0.20]) less arch height drop in 3D-print compared to Traditional. The SPM analyses revealed condition main effects on ankle moment (p < 0.001) and ankle power (p < 0.001). There were significant differences between control condition and both 3D-print and Traditional conditions. For ankle moment and power, there were no differences between 3D-print and Traditional conditions. SIGNIFICANCE:3D-printed FOs are more effective in reducing arch height drop, whist both FOs lowered ankle plantarflexion moment and power compared to no FOs. The results support the use of 3D-printed FOs as being equally effective as traditionally-made FOs in changing lower limb biomechanics for a population of flat-footed individuals with unilateral plantar fasciopathy. 10.1016/j.gaitpost.2022.06.006
The influence of the Peroneus Longus muscle on the foot under axial loading: A CT evaluated dynamic cadaveric model study. Dullaert K,Hagen J,Klos K,Gueorguiev B,Lenz M,Richards R G,Simons P Clinical biomechanics (Bristol, Avon) BACKGROUND:Subtle hypermobility of the first tarsometatarsal joint can occur concomitantly with other pathologies and may be difficult to diagnose. Peroneus Longus muscle might influence stability of this joint. Collapse of the medial longitudinal arch is common in flatfoot deformity and the muscle might also play a role in correcting Meary's angle. METHODS:A radiolucent frame was used to simulate weightbearing during CT examination. Eight pairs fresh-frozen lower legs were imaged in neutral position under non-weightbearing (75N), weightbearing (700N) and with 15kg weights hung from Peroneus Longus tendon. Measurements included first metatarsal rotation, intermetatarsal angle, first tarsometatarsal joint subluxation and Meary's angle. FINDINGS:Weightbearing significantly increased Meary's angle and significantly decreased first tarsometatarsal joint subluxation (both P<0.01). Pulling Peroneus Longus tendon significantly increased first metatarsal rotation (P<0.01), significantly decreased the intermetatarsal angle (P<0.01) and increased non-significantly Meary's angle (P=0.52). INTERPRETATION:A considerable effect weightbearing has on the medial longitudinal arch and first tarsometatarsal joint was observed. Pulling Peroneus Longus tendon improved first metatarsal subluxation but increased its rotation. The study calls into question the importance of this tendon in maintaining the medial longitudinal arch and raises concerns about rotational deformity of the first metatarsal following hallux valgus correction without first tarsometatarsal arthrodesis. CLINICAL RELEVANCE:Study outcomes will provide more insight in foot pathology. WHAT IS KNOWN ABOUT THE SUBJECT:Weightbearing affects anatomy of the foot. No reliable information is available concerning the influence of the Peroneus muscle. WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE:This study investigates the influence of weightbearing and the impact the Peroneus muscle on the anatomy of the foot. 10.1016/j.clinbiomech.2016.03.001
Eccentric ankle arthritis in the sagittal plane: a novel description of anterior and posterior ankle arthritis. Kim Jaeyoung,Kim Ji-Beom,Lee Woo-Chun Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:To report radiographic characteristics of anterior and posterior ankle arthritis, which demonstrates the eccentric narrowing of either aspect of the tibiotalar joint in the sagittal plane. METHODS:Radiographic analysis of 19 ankles with anterior arthritis and 16 ankles with posterior arthritis was performed, which were defined as having both (1) eccentric narrowing of the anterior or posterior tibiotalar joint space on lateral radiographs and (2) talar tilt angle less than 4 degrees on anteroposterior radiographs. Measured radiographic parameters were: Talar tilt angle, medial distal tibial angle (MDTA), talar center migration (TCM), anterior distal tibial angle (ADTA), tibial axis-to-talus ratio (TT ratio), talo-first metatarsal (Meary) angle, hindfoot alignment angle (HAA), hindfoot moment arm, and mechanical axis deviation (MAD). An Intergroup comparison analysis, including a normal control group, was also performed. RESULTS:The TT ratio was significantly different between each group, indicating a distinct talus position in the sagittal plane. The anterior group had a significantly larger TCM than the control group and lower ADTA compared to other groups, indicating medial translation of the talus and anterior opening of the tibial plafond. The posterior group demonstrated a significantly higher Meary angle and lower HAA compared to other groups and lower MDTA compared to the control group, indicating lower medial longitudinal arch, valgus heel alignment, and varus tibial plafond. The MAD was significantly higher in both the anterior and posterior groups than the control group, indicating varus lower limb alignment. CONCLUSION:Anterior ankle arthritis demonstrated anteromedial translation of the talus and anterior opening of the tibial plafond. Posterior ankle arthritis was associated with the lower medial longitudinal arch and hindfoot valgus, indicating an association with flatfoot deformity. Both anterior and posterior ankle arthritis were associated with varus lower limb alignment. 10.1016/j.fas.2020.12.013
Navicular drop is negatively associated with flexor hallucis brevis thickness in community-dwelling older adults. Fukumoto Yoshihiro,Asai Tsuyoshi,Ichikawa Masaru,Kusumi Hiroyuki,Kubo Hiroki,Oka Tomohiro,Kasuya Akihiko Gait & posture BACKGROUND:Flatfoot is characterized as a lower longitudinal arch and is a common foot deformity in older adults. Foot intrinsic muscle dysfunction has been considered as one of the factors for a lower medial longitudinal arch. The objective of this study was to investigate the association of the navicular drop with the thickness of foot intrinsic muscles in older adults. RESEARCH QUESTION:Which intrinsic muscle contributes most to support the medial longitudinal arch in older adults? METHODS:We studied 88 community-dwelling older adults (mean age 74.2 ± 6.2 years). We measured the navicular height, the calcaneus inclination, and hallux valgus angle on the right foot in the sitting and standing positions using a 3D foot scanner. Then, we calculated the navicular drop and changes in the calcaneus inclination from the sitting to the standing position. The muscle thickness of the flexor hallucis brevis (FHB), flexor digitorum brevis (FDB), and abductor hallucis (AbH) was measured on the right foot using Bmode ultrasonography. RESULTS:Multiple regression analysis demonstrated that FHB thickness was significantly associated with navicular height in the standing positions (β = 8.568, P = 0.016) as well as navicular drop (β = -9.495, P = 0.037) after adjusting for age, sex, height, weight, and hallux valgus angle. There was no association with FDB or AbH. The thickness of any intrinsic muscle was not associated with the calcaneus inclination or changes in the calcaneus inclination. SIGNIFICANCE:Our data suggest that FHB plays an important role in preventing navicular drop and that intrinsic muscles likely do not contribute to the rearfoot angle in older adults. 10.1016/j.gaitpost.2020.03.009
Decision Tree-Based Foot Orthosis Prescription for Patients with Pes Planus. International journal of environmental research and public health Pes planus, one of the most common foot deformities, includes the loss of the medial arch, misalignment of the rearfoot, and abduction of the forefoot, which negatively affects posture and gait. Foot orthosis, which is effective in normalizing the arch and providing stability during walking, is prescribed for the purpose of treatment and correction. Currently, machine learning technology for classifying and diagnosing foot types is being developed, but it has not yet been applied to the prescription of foot orthosis for the treatment and management of pes planus. Thus, the aim of this study is to propose a model that can prescribe a customized foot orthosis to patients with pes planus by learning from and analyzing various clinical data based on a decision tree algorithm called classification and regressing tree (CART). A total of 8 parameters were selected based on the feature importance, and 15 rules for the prescription of foot orthosis were generated. The proposed model based on the CART algorithm achieved an accuracy of 80.16%. This result suggests that the CART model developed in this study can provide adequate help to clinicians in prescribing foot orthosis easily and accurately for patients with pes planus. In the future, we plan to acquire more clinical data and develop a model that can prescribe more accurate and stable foot orthosis using various machine learning technologies. 10.3390/ijerph191912484
The ground reaction force thresholds for detecting postural stability in participants with and without flat foot. Sung Paul S Journal of biomechanics Foot mobility commonly contributes to injury via altered motion of the lower extremities. However, there is a lack of understanding of sensitive kinetic changes with flat foot. The purpose of this study was to investigate the threshold that best distinguishes between participants with and without flat foot. The kinetic stability index was developed based on the three-dimensional data from the ground reaction force (GRF) during one leg standing. In total, 34 control participants and 30 participants with flat foot were asked to maintain one leg standing for 25s with the contra lateral hip and knee flexed approximately 90°. The various thresholds (3, 7, 15, 30, 50, and 200N) were analyzed by the kinetic stability index. The standing time was not significantly different between groups (t=1.07, p=0.28); however, there were significant differences on threshold level (F=369.23, p=0.001) as well as group interactions with threshold (F=6.72, p=0.01). The post hoc test indicated that less than 15N was the best to detect the kinetic stability index between the groups. Clinicians need to understand sensitive threshold settings to differentiate the participants with and without flat foot. The threshold changes might be altered to detect postural deficits by the kinetic stability index. 10.1016/j.jbiomech.2015.11.004
Clinical and radiological outcomes of corrective exercises and neuromuscular electrical stimulation in children with flexible flatfeet: A randomized controlled trial. Abd-Elmonem Amira M,El-Negamy Emam H,Mahran Mahmoud A,Ramadan Asmaa T Gait & posture BACKGROUND:Flexible flatfeet are common among children being scarcely symptomatic requires no specific treatment and resolves spontaneously. However, flexible flatfoot tends to advance and deteriorate overtime and eventually resulting in significant impairments such as plantar fasciitis and patellofemoral pain syndrome. RESEARCH QUESTION:What is the effect of corrective exercises and neuromuscular electrical stimulation in children with flexible flatfeet? METHOD:This is a randomized controlled trial with 72 children, seven to twelve yearsold, randomly assigned to either intervention or control group (36 children for each group) and engaged in a four months (3 sessions/week) of corrective exercise and neuromuscular electrical stimulation or corrective exercise and sham neuromuscular electrical stimulation respectively. Assessments of Staheli's arch index (through foot print), navicular drop (through navicular drop test) and radiographic indexes (through anterior-posterior and medio-lateral X-ray) of both feet were performed before and after the intervention programs. RESULTS:Study groups were comparable with respect to all outcome measures at entry (P > 0.05). Within group comparison showed significant improvements in all measured variables. Further, between groups comparison revealed significant higher improvements (P < 0.05) in right and left feet Staheli's arch index, navicular drop as well as the radiographic indexes in favor of the intervention group. SIGNIFICANCE:Integration of corrective exercises and neuromuscular electrical stimulation is more effective than exercises alone for providing clinical and radiological improvements in children with flexible flatfeet. 10.1016/j.gaitpost.2021.06.008
Shank and rearfoot coordination and its variability during running in flatfoot. Takabayashi Tomoya,Edama Mutsuaki,Inai Takuma,Kubo Masayoshi Journal of biomechanics Flatfoot is a risk factor for patellofemoral pain syndrome (PFPS), and excessive rearfoot eversion occurring in flatfoot has been associated with the development and progression of PFPS; however, the mechanism remains unclear. This study aimed to investigate transverse shank and frontal rearfoot coordination patterns and variability when running with normal foot and flatfoot. Participants with normal foot (n = 13) and flatfoot (n = 13) were asked to run at their preferred speed. The coupling angle between the shank and rearfoot, representing intersegmental coordination, was calculated using the modified vector coding technique and categorized into four coordination patterns. Standard deviation of the coupling angle was computed as a measure of coordination variability during the stance phase. No differences in the characteristics and spatiotemporal parameters between groups were found, and all participants had rearfoot strike pattern. During midstance, the flatfoot group showed a significantly greater proportion of anti-phase with proximal (shank) dominancy than the normal foot group (p = 0.04, effect size = 0.88 [large]). Furthermore, flatfoot group showed a significantly greater in variability than the normal foot group (p = 0.03, effect size = 0.91 [large]). This study's results may help explain why flatfoot is likely to result in PFPS. However, the occurrence mechanism of running injuries like PFPS is multi- factorial. Since these results alone are not sufficient to explain the cause-effect relationship between flatfoot and injuries like PFPS, a prospective study including other factors such as patellofemoral joint stress would also be needed. 10.1016/j.jbiomech.2020.110119
Comparison of the degree of pes planovalgus and muscle mass of the ankle joint and foot muscles between children with Down syndrome and children with typical development. Masaki Mitsuhiro,Sugawara Karin,Iizuka Yuka,Uchikawa Yuki,Isobe Honoka,Hattori Fuyumi,Mano Koki,Saito Keiko,Sugino Ayaka,Kato Kana,Sakaino Kenji Journal of biomechanics We aimed to compare the degree of pes planovalgus and muscle mass of the ankle joint and foot muscles between children with Down syndrome (DS) and children with typical development (TD). We also examined the association of the degree of pes planovalgus with muscle mass of the ankle joint and foot muscles in children with DS and children with TD. The subjects were 24 children with TD (control [CTR] group) and 23 children with DS (DS group). To assess pes planovalgus, the Arch Height Index (AHI) in the standing position was measured. Muscle thickness of the ankle joint and foot muscles was measured using an ultrasound imaging device. The AHI and thickness of the soleus and tibialis posterior muscles were significantly lower in the DS group than those in the CTR group. The thickness of the flexor digitorum longus muscle was significantly greater in the DS group than that in the CTR group. Stepwise regression analysis revealed that the thickness of the flexor digitorum longus muscle was a significant and independent factor of the AHI in children comprising the CTR and DS groups. The thickness of the flexor digitorum longus muscle increased with decreasing AHI. The results of this study suggest that the AHI and muscle mass of the soleus and tibialis posterior muscles decrease, while muscle mass of the flexor digitorum longus muscle increases in children with DS. The results also indicate that decreased AHI is associated with increased muscle mass of the flexor digitorum longus muscle in children. 10.1016/j.jbiomech.2021.110482
A computational model of force within the ligaments and tendons in progressive collapsing foot deformity. Journal of orthopaedic research : official publication of the Orthopaedic Research Society Progressive collapsing foot deformity results from degeneration of the ligaments and posterior tibial tendon (PTT). Our understanding of the relationship between their failures remains incomplete. We sought to improve this understanding through computational modeling of the forces in these soft tissues. The impact of PTT and ligament failures on force changes in the remaining ligaments was investigated by quantifying ligament force changes during simulated ligament and tendon cutting in a validated finite element model of the foot. The ability of the PTT to restore foot alignment was also evaluated by increasing the PTT force in a foot with attenuated ligaments and comparing the alignment angles to the intact foot. We found that failure of any one of the ligaments led to overloading the remaining ligaments, except for the plantar naviculocuneiform, first plantar tarsometatarsal, and spring ligaments, where removing one led to unloading the other two. The combined attenuation of the plantar fascia, long plantar, short plantar, and spring ligaments significantly overloaded the deltoid and talocalcaneal ligaments. Isolated PTT rupture had no effect on foot alignment but did increase the force in the deltoid and spring ligaments. Moreover, increasing the force within the PTT to 30% of body weight was effective at restoring foot alignment during quiet stance, primarily through reducing hindfoot valgus and forefoot abduction as opposed to improving arch collapse. Our findings suggest that early intervention might be used to prevent the progression of deformity. Moreover, strengthening the PTT through therapeutic exercise might improve its ability to restore foot alignment. 10.1002/jor.25380
Kinematic differences between neutral and flat feet with and without symptoms as measured by the Oxford foot model. Kerr C M,Zavatsky A B,Theologis T,Stebbins J Gait & posture BACKGROUND:Flatfoot is a common presentation in children. It is usually asymptomatic, though a small number of children experience pain. Foot function during flatfoot walking is rarely considered, yet as an activity that places significant demands on the feet, this could explain the differences in terms of symptoms. RESEARCH QUESTION:This paper investigates walking patterns in neutral and flat feet, with and without symptoms, to determine which kinematic parameters are associated with symptomatic flat feet. METHODS:This is a retrospective study in which one hundred and six children between five and 18 years old were assessed by a physiotherapist for foot posture. Each foot was classified into one of four groups, giving 98 asymptomatic neutral, 47 asymptomatic mild flat, 29 asymptomatic flat, and 38 symptomatic flat feet with complete data for analysis. Using Plug-In-Gait and Oxford-Foot-Model markers, walking kinematics were measured, along with ground reaction forces. Median values of 14 lower limb joint angles were calculated at foot strike, midstance, and foot off. Each foot was treated as an independent sample. ANOVA and ANCOVA (with the speed-related variable relative stride length as the covariate) and post-hoc tests were used to assess whether angles differed between groups. RESULTS:The symptomatic flat feet showed significant differences from asymptomatic groups (most commonly the neutral feet) in terms of hip flexion, knee flexion and varus, hindfoot inversion-eversion, and forefoot abduction-adduction. Increased forefoot abduction occurred throughout stance phase in symptomatic flatfooted participants compared to all asymptomatic groups. SIGNIFICANCE:The results suggest that foot motion in the transverse plane is closely associated with the presence of symptoms in flat feet and that this is accompanied by changes in the kinematics of the ankle, knee, and hip. 10.1016/j.gaitpost.2018.10.015
Influence of arch support heights on the internal foot mechanics of flatfoot during walking: A muscle-driven finite element analysis. Peng Yinghu,Wong Duo Wai-Chi,Chen Tony Lin-Wei,Wang Yan,Zhang Guoxin,Yan Fei,Zhang Ming Computers in biology and medicine BACKGROUND:Different arch support heights of the customized foot orthosis could produce different effects on the internal biomechanics of the foot. However, quantitative evidence is scarce. Therefore, we aimed to investigate and quantify the influence of arch support heights on the internal foot biomechanics during walking stance. METHODS:We reconstructed a foot finite element model from a volunteer with flexible flatfoot. The model enabled a three-dimensional representation of the plantar fascia and its interactions with surrounding osteotendinous structures. The volunteer walked in foot orthosis with different arch heights (low, neutral, and high). Muscle forces during gaits were calculated by a multibody model and used to drive a foot finite element model. The foot contact pressures and plantar fascia strains in different regions were compared among the insole conditions at the first and second vertical ground reaction force (VGRF) peak and VGRF valley instants. RESULTS:The results indicated that peak foot pressures decreased in balanced standing and second VGRF as the arch support height increased. However, peak midfoot pressures increased during all simulated instants. Meanwhile, high arch support decreased the plantar fascia loading by 5%-15.4% in proximal regions but increased in the middle and distal regions. CONCLUSION:Although arch support could generally decrease the plantar foot pressure and plantar fascia loading, the excessive arch height may induce high midfoot pressure and loadings at the central portion of the plantar fascia. The consideration of fascia-soft tissue interaction in modeling could improve the prediction of plantar fascia strains towards design optimization for orthoses. 10.1016/j.compbiomed.2021.104355
The impact of ligament tears on joint contact mechanics in progressive collapsing foot deformity: A finite element study. Clinical biomechanics (Bristol, Avon) BACKGROUND:Patients with longstanding progressive collapsing foot deformity often develop osteoarthritis of the ankle, midfoot, or hindfoot joints, which can be symptomatic or lead to fixed deformities that complicate treatment. The development of deformity is likely caused by ligament degeneration and tears. However, the effect of individual ligament tears on changes in joint contact mechanics has not been investigated. METHODS:A validated finite element model of the foot was used to compare joint contact areas, forces, and pressures between the intact and collapsed foot, and to evaluate the effect of individual ligament tears on joint contact mechanics. FINDINGS:Collapsing the foot resulted in an increase in contact pressure in the subtalar, calcaneocuboid, tibiotalar, medial naviculocuneiform, and first tarsometatarsal joints but a decrease in contact pressure in the talonavicular joint. Rupture of the spring ligament was the main contributor to increased calcaneocuboid and subtalar joint contact pressures and decreased medial naviculocuneiform and first tarsometatarsal joint contact pressures, as well as talonavicular subluxation. Deltoid ligament rupture was the primary source of increased contact pressure in the medial naviculocuneiform, first tarsometatarsal, and tibiotalar joints. INTERPRETATION:Degenerative tearing of the ligaments in flatfoot deformity leads to increased joint contact pressures, primarily in the calcaneocuboid, subtalar, and tibiotalar joints, which has been implicated in the development of osteoarthritis in these joints. An improved understanding of the relationship between ligament tears and joint contact pressures could provide support for the use of ligament reconstructions to prevent the development of arthrosis. 10.1016/j.clinbiomech.2022.105630
The relationship between foot posture and lower limb kinematics during walking: A systematic review. Buldt Andrew K,Murley George S,Butterworth Paul,Levinger Pazit,Menz Hylton B,Landorf Karl B Gait & posture Variations in foot posture, such as pes planus (low-arched foot) or pes cavus (high-arched foot), are thought to be an intrinsic risk factor for injury due to altered motion of the lower extremity. Hence, the aim of this systematic review was to investigate the relationship between foot posture and lower limb kinematics during walking. A systematic database search of MEDLINE, CINAHL, SPORTDiscus, Embase and Inspec was undertaken in March 2012. Two independent reviewers applied predetermined inclusion criteria to selected articles for review and selected articles were assessed for quality. Articles were then grouped into two broad categories: (i) those comparing mean kinematic parameters between different foot postures, and (ii) those examining associations between foot posture and kinematics using correlation analysis. A final selection of 12 articles was reviewed. Meta-analysis was not conducted due to heterogeneity between studies. Selected articles primarily focused on comparing planus and normal foot postures. Five articles compared kinematic parameters between different foot postures - there was some evidence for increased motion in planus feet, but this was limited by small effect sizes. Seven articles investigated associations between foot posture and kinematics - there was evidence that increasing planus foot posture was positively associated with increased frontal plane motion of the rearfoot. The body of literature provides some evidence of a relationship between pes planus and increased lower limb motion during gait, however this was not conclusive due to heterogeneity between studies and small effect sizes. 10.1016/j.gaitpost.2013.01.010
Assessment of Posterior and Middle Facet Subluxation of the Subtalar Joint in Progressive Flatfoot Deformity. Foot & ankle international BACKGROUND:Adult acquired flatfoot deformity (AAFD) is a complex 3-dimensional pathology characterized by peritalar subluxation (PTS) of the hindfoot. For many years, PTS was measured at the posterior facet of the subtalar joint. More recently, subluxation of the middle facet has been proposed as a more accurate and reliable marker of symptomatic AAFD, enabling earlier detection. The objective of this study was to compare the amount of subluxation between the medial and posterior facets in patients with AAFD. METHODS:In this institutional review board-approved retrospective comparative study, a total of 76 patients with AAFD (87 feet) who underwent standing weightbearing computed tomography (WBCT) as a standard baseline assessment of their foot deformity were analyzed. Two blinded fellowship-trained orthopedic foot and ankle surgeons with >10 years of experience measured subtalar joint subluxation (as a percentage of joint uncoverage) at the both posterior and middle facets. One of the readers also measured the foot and ankle offset (FAO). PTS measurements were performed at the sagittal midpoint of the articular facets using coronal plane WBCT images. Intra- and interobserver agreement was measured for PTS measurements using the intraclass correlation coefficient (ICC). The intermethod agreement between the posterior and middle facet subluxation was assessed using Spearman's correlation and bivariate analysis. Paired comparison of the measurements was performed using the Wilcoxon test. A multivariate analysis and a partition prediction model were used to assess influence of PTS measurements on FAO values. values of <.05 were considered significant. RESULTS:ICCs for intra- and interobserver reliabilities were 0.97 and 0.93, respectively, for posterior and 0.99 and 0.97, respectively, for middle facet subluxation. The intermethod Spearman's correlation between subluxation of the posterior and middle facets was measured at 0.61. In a bivariate analysis, both measurements were found to be significantly and linearly correlated ( < .0001; = 0.42). Measurements of middle facet subluxation were found to be significantly higher than those for posterior facet subluxation, with a median difference (using the Hodges-Lehman factor) of 17.7% ( < .001; 95% CI, 10.9%-23.6%). We also found that for every 1% increase in posterior facet subluxation there was a corresponding 1.6-fold increase in middle facet subluxation. Only middle facet subluxation measurements were found to significantly influence FAO calculations ( = .003). The partition prediction model demonstrated that a middle facet subluxation value of 43.8% represented an important threshold for increased FAO. CONCLUSION:This study is the first to compare WBCT measurements of subtalar joint subluxation at the posterior and middle facets as markers of PTS in patients with AAFD. We found a positive linear correlation between the measurements, with subluxation of the middle facet being significantly more pronounced than that of the posterior facet by an average of almost 18%. This suggests that middle facet subluxation may provide an earlier and more pronounced marker of progressive PTS in patients with AAFD. LEVEL OF EVIDENCE:Level III, retrospective comparative cohort study. 10.1177/1071100720936603
Effect of posterior tibial tendon dysfunction on unipedal standing balance test. Kulig Kornelia,Lee Szu-Ping,Reischl Stephen F,Noceti-DeWit Lisa Foot & ankle international BACKGROUND:Foot pain and diminished functional capacity are characteristics of tibialis posterior tendon dysfunction (TPTD). This study tested the hypotheses that women with TPTD would have impaired performance of a unipedal standing balance test (USBT) and that balance performance would be related to the number of single limb heel raises (SLHR). METHODS:Thirty-nine middle-aged women, 19 with early stage TPTD (stage I and II), were instructed to perform 2 tasks; a USBT and repeated SLHR. Balance success was defined as a 10-second stance. For those who were successful, center of pressure (COP) data in anterior-posterior (AP) and medial-lateral (ML) directions were recorded as a measure of postural sway. SLHR performance was divided into 3 bins (≤2; 3-9 and > 10 repetitions). The between-balance success on performing the SLHR test was analyzed using the Fisher's exact test (2 × 3). Independent t tests were used to compare between-group differences in postural sway. Relationship of postural sway to the number of heel raises was assessed using Spearman's rho. RESULTS:The success rate of the USBT was significantly lower in women with TPTD than the controls (47% vs 85%, P = .041). In addition, women with TPTD who completed the USBT exhibited increased AP COP displacement (14.0 ± 7.4 vs 8.4 ± 1.3 mm, P = .008), and a strong trend of increased ML COP displacement (8.3 ± 4.5 vs 6.1 ± 1.2 mm, P = .050). The success rate of USBT was correlated with the number of SLHR (P = .01). The AP and ML COP displacement were correlated with SLHR (r = -.538 and .495), respectively. CONCLUSIONS:Women with TPTD have difficulty in performing the USBT. Performance of the USBT and SLHR are highly correlated and predictive of each other. CLINICAL RELEVANCE:A unipedal balance test may be used as a proxy TPTD assessment tool to the heel raising test when pain prevents performance. LEVEL OF EVIDENCE:Level III, case control study. 10.1177/1071100714551020
The tibialis posterior tendon footprint: an anatomical dissection study. Willegger Madeleine,Seyidova Nargiz,Schuh Reinhard,Windhager Reinhard,Hirtler Lena Journal of foot and ankle research BACKGROUND:The tibialis posterior tendon (TPT) is the main dynamic stabilizer of the medial longitudinal arch of the foot. Especially in adult acquired flatfoot deformity (AAFD) the TPT plays a detrimental role. The pathology and function of the tendon have been extensively investigated, but knowledge of its insertional anatomy is paramount for surgical procedures. This study aimed to analyze the complex distal footprint anatomy of the TPT. METHODS:Forty-one human anatomical specimens were dissected and the distal TPT was followed to its bony footprints. After tendon removal the footprints were marked with ink. Standardized photographs were taken and consecutively analyzed by digital imaging measurements. Footprint length, width, area of insertion, location, and shape was studied regarding the main insertion at the navicular bone. RESULTS:All specimens had the main TPT insertion at the navicular bone (41/41, 100%). Sixty-three percent of navicular TPT insertions were located at the plantar aspect. The mean navicular footprint measured 12.1 mm × 6.9 mm in length and width, respectively. The tendon further spread into several slips which anchored the tibialis posterior deep in the plantar arch. TPT insertions were highly variable with an involvement of up to eight distinct bony footprints in the mid- and hindfoot. The second most common additional footprint was the lateral cuneiform (93% of dissected feet), followed by the medial cuneiform (80%), the metatarsal bases [1-5] (80%), the cuboid (46%), the intermediate cuneiform (19%), and the calcaneus (12%). CONCLUSIONS:The present study adds to current knowledge on the footprint anatomy of the TPT. Based on the findings of this study we advocate a plantar location of flexor digitorum longus tendon transfer in flexible AAFD in order to restore the anatomical lever and insertion of the TPT. 10.1186/s13047-020-00392-1
Understanding the role of foot biomechanics on regional foot orthosis deformation in flatfoot individuals during walking. Hajizadeh Maryam,Desmyttere Gauthier,Ménard Anne-Laure,Bleau Jacinte,Begon Mickael Gait & posture BACKGROUND:Foot orthoses (FOs) are one of the most common interventions to restore normal foot mechanics in flatfoot individuals. New technologies have made it possible to deliver customized FOs with complex designs for potentially better functionalities. However, translating the individuals' biomechanical needs into the design of customized FOs is not yet fully understood. RESEARCH QUESTION:Our objective was to identify whether the deformation of customized FOs is related to foot kinematics and plantar pressure during walking. METHODS:The kinematics of multi-segment foot and FOs contour were recorded together with plantar pressure in 17 flatfoot individuals while walking with customized FOs. The deformation of FOs surface was predicted from its contour kinematics using an artificial neural network. Plantar pressure map and deformation were divided into five anatomically based regions defined by the corresponding foot segments. Forward stepwise linear mixed models were built for each of the four gait phases to determine the feet-FOs interaction. RESULTS:It was observed that some associations existed between foot kinematics and pressure with regional FOs deformation. From heel-strike to foot-flat, longitudinal arch angle was associated with FOs deformation in forefoot. From foot-flat to midstance, rearfoot eversion accounted for variation in the deformation of medial FOs regions, and forefoot abduction for the lateral regions. From midstance to heel-off, rearfoot eversion, longitudinal arch angle, and plantar pressure played significant role in deformation. Finally, from heel-off to toe-off, forefoot adduction affected the deformation of forefoot and midfoot. SIGNIFICANCE:This study provides guidelines for designing customized FOs. Flatfoot individuals with excessive rearfoot eversion or very flexible medial arches require more support on medial FOs regions, while the ones with excessive forefoot abduction need the support on lateral regions. However, a compromise should be made between the level of support and the level of increase in plantar pressure to avoid stress on foot structures. 10.1016/j.gaitpost.2021.10.015
Differences in the coordination and its variability among foot joints during running in neutral foot and flatfoot. Scandinavian journal of medicine & science in sports Flatfoot is a well-known foot deformity, with a prevalence of 11.2%-29.0% among adults. Running injuries can occur in individuals with flatfoot; however, the underlying mechanism remains unknown. We investigated the coordination pattern and variability among foot joints while running by comparing participants with neutral foot and with flatfoot. Participants with neutral foot (n = 15) and flatfoot (n = 15) were asked to run at their preferred speed. Using the modified vector coding technique, the coupling angle between the foot joints, representing interjoint coordination, was calculated and categorized into four coordination patterns. The standard deviation of the coupling angle was computed to measure the coordination variability during the stance phase. There were no differences in the spatiotemporal parameters (speed, step length, and cadence) between the groups. In the sagittal rearfoot and sagittal midfoot coordination patterns, the flatfoot group showed a significantly greater proportion of anti-phase with proximal dominancy and a lower proportion of in-phase with proximal dominancy than the neutral foot group during early stance. Coordination variabilities between the sagittal rearfoot and sagittal midfoot (midstance), between the sagittal midfoot and sagittal forefoot (early stance), and between the frontal rearfoot and sagittal midfoot (midstance) were greater in the flatfoot group than in the neutral foot group. This may explain why those with flatfoot are likely to experience running injuries. 10.1111/sms.14267
Difference in static and dynamic stability between flexible flatfeet and neutral feet. Kim Jeong-Ah,Lim One-Bin,Yi Chung-Hwi Gait & posture Different postural stability may be a contributor to secondary injuries in individuals with flexible flatfeet (FF) compared to those with neutral feet (NF). However, the differences between static and dynamic stability of FF and NF have not been examined. This study compared the static and dynamic stability of subjects with FF and NF and investigated the relationship between static and dynamic stability. Twenty-eight subjects (14 each in the FF and NF groups) performed three tasks (single leg standing with eyes open, with eyes closed, and the Y balance test). We quantified the center of pressure (COP) speed and Y balance test score (Y score) within the tasks. COP speed was significantly greater in the FF group than in the NF group under both conditions (eyes open and closed) and directions (anteroposterior and mediolateral). Y scores did not differ significantly between the two groups. No significant relationship was observed between the COP speed and Y score in either group. These results show that individuals with FF have different static stabilities, but not dynamic stabilities, compared with those with NF. This might indicate the absence of a relationship between static and dynamic stabilities. 10.1016/j.gaitpost.2014.12.012
Biomechanical Effects of Graft Shape for the Evans Lateral Column Lengthening Procedure: A Patient-Specific Finite Element Investigation. Foot & ankle international BACKGROUND:The Evans calcaneal lengthening osteotomy procedure is widely used for correcting progressive collapsing foot deformity. However, it can result in overcorrection and degenerations of the calcaneocuboid joint. Different shapes of graft have been used in the Evans calcaneal osteotomy, but potential differences in their biomechanical effects is still unclear. The present study was designed to explore the biomechanical effects of graft shape and improve the Evans procedure to avoid or minimize detrimental effects. METHODS:Twelve patient-specific finite element models were established and validated. A triangular or rectangular wedge of varying size was inserted at the lateral edge of calcaneus, and the degree of correction was quantified. The stress in spring ligaments and plantar fascia and the contact characteristics of the talonavicular and calcaneocuboid joints were calculated and compared accordingly. RESULTS:The rectangular graft provided a much higher degree of correction than triangular grafts did. However, the contact characteristics of the calcaneocuboid joint and talonavicular joint were abnormal, with clear sensitivity to increased graft size, and the modeled strain of the spring ligament increased. CONCLUSION:The finite element analysis predicts that the rectangular grafts provide a higher degree of correction, but risks overcorrection compared with triangular grafts. The triangular graft may have a lower degree of disturbance to the biomechanical behaviors of the midtarsal joint. CLINICAL RELEVANCE:The model shows that both the shape and size of an Evans osteotomy bone wedge can have effects on the contiguous joints and ligamentous structures. Those effects should be considered when selecting a bone wedge for an Evans calcaneal osteotomy. LEVEL OF EVIDENCE:Level III, case-control study. 10.1177/10711007211043822
Predictors of the Biomechanical Effects of Customized Foot Orthoses in Adults With Flat-Arched Feet. Arnold John B,May Thomas,Bishop Christopher Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine OBJECTIVE:To determine the potential presence and characteristics of biomechanical responders to customized foot orthoses during walking in adults with flat-arched feet. DESIGN:Experimental, repeated-measures. SETTING:University clinic and laboratory. PARTICIPANTS:Eighteen symptom-free adults with flat-arched feet. INTERVENTIONS:Customized foot orthoses. MAIN OUTCOME MEASURES:In-shoe foot biomechanics were measured during walking with and without customized foot orthoses using 3D analysis. Selected kinematic and kinetic variables during baseline walking were compared between subgroups who displayed reductions in calcaneal eversion with foot orthoses to those with no change or increases. RESULTS:Biomechanical responders displayed significantly greater peak calcaneal eversion (+2.2 degrees, P = 0.009). Time to peak calcaneal eversion (-11%, P = 0.006), peak dorsiflexion of the hallux (-6 degrees, P = 0.001), and medial-lateral excursion of the center of pressure during loading response were all reduced in the responder subgroup (-2 mm, P ≤ 0.001). Variables significantly different between subgroups were moderately associated with the response to foot orthoses (canonical correlation = 0.687, effect size = 0.47, P = 0.063). CONCLUSIONS:Individuals with increased dynamic foot pronation were more likely to show a favorable biomechanical response to customized foot orthoses, providing preliminary evidence to support the stratified use of foot orthoses to optimize their effectiveness. 10.1097/JSM.0000000000000461
Relationship of Body Mass Index and Footprint Morphology to the Actual Height of the Medial Longitudinal Arch of the Foot. Rosende-Bautista Carolina,Munuera-Martínez Pedro V,Seoane-Pillado Teresa,Reina-Bueno María,Alonso-Tajes Francisco,Pérez-García Sergio,Domínguez-Maldonado Gabriel International journal of environmental research and public health The medial longitudinal arch height of the foot is linked to individual characteristics such as sex and body mass index, and these characteristics have been shown to be associated with conditions such as flat feet. In this cross-sectional descriptive study, we examined the medial longitudinal arch morphology in an adult population to determine if there are differences related to sex and body mass index, and values were obtained for the foot posture index. Normalized anthropometric measurements and arch indices were calculated from footprints. Groups, defined by sex and body mass index, were compared, and the correlations between body mass index and the variables were determined. In the population studied (266 women and 177 men), significant differences between men and women for the foot posture index and normalized arch measurements were found. Analysis of the variables related to body mass index indicated there were significant differences in arch indices. Significant differences and positive correlations were also found between the arch index and body mass index for the left and right feet among the men and women studied. The results obtained allow us to reflect on and analyze whether the medial longitudinal arch morphology classification methods used in the clinical and research setting are adequate or whether the influence of factors such as body mass index can generate confusion. 10.3390/ijerph18189815
Differences in rearfoot, midfoot, and forefoot kinematics of normal foot and flatfoot during running. Takabayashi Tomoya,Edama Mutsuaki,Inai Takuma,Kubo Masayoshi Journal of orthopaedic research : official publication of the Orthopaedic Research Society Flatfoot is a common foot deformity, which could contribute to running injuries such as medial tibial stress syndrome. Intrafoot kinematics of flatfoot during walking have often been documented using multisegment foot models. However, the intrafoot kinematics of flatfoot during running remains unclear, despite the possible relationship between flatfoot and running injuries. We aimed to clarify rearfoot, midfoot, and forefoot kinematics when running in participants with normal foot and flatfoot. Participants with the normal foot (n = 14) and flatfoot (n = 14) were asked to runover-ground at their preferred speed. Three-dimensional kinematics of the rearfoot, midfoot, and forefoot during running were calculated based on the Rizzoli foot model. A two-sample t-test of statistical parametric mapping was performed to determine differences between normal foot and flatfoot in time histories of intrafoot kinematics during running. No differences were found between groups in characteristics and spatiotemporal parameters. In the frontal rearfoot angle, a significantly increased eversion from 24% to 100% (p < .001) was observed in the flatfoot compared to the normal foot. At the midfoot angle, a significantly increased eversion from 0% to 4% (p < .049) and 21% to 100% (p < .001) was observed in the flatfoot compared to the normal foot. At the forefoot angle, a significantly increased inversion from 6% to 17% (p < .047) was observed in the flatfoot compared to the normal foot. These findings may be useful to explain why flatfoot could contribute to running injuries such as medial tibial stress syndrome. 10.1002/jor.24877
The Impact of Foot Orthoses and Exercises on Pain and Navicular Drop for Adult Flatfoot: A Network Meta-Analysis. Hoang Ngoc-Tuyet-Trinh,Chen Shuya,Chou Li-Wei International journal of environmental research and public health BACKGROUND:Adult flatfoot leads to injury and decreased quality of life. The most widely applied noninvasive approaches are wearing foot orthoses or exercising. Both interventions raise controversy about reducing pain and neutralizing foot posture. This study investigated the impact of foot orthoses and exercise on pain and navicular drop (present for foot posture). METHODS:Four databases were used: MEDLINE, PubMed, Web of Science, and Cochrane, from the earliest records to November 2020. Randomized controlled studies focused on adult flatfoot that evaluated the effect of exercise and foot orthoses on pain and navicular drop were extracted. We used data analysis to estimate the relative effect of heterogeneity using and publication bias using funnel plots. RESULTS:Ten studies were identified through to November 2020. Active interventions (AIs) were exercise and exercise combined with foot orthoses; passive interventions (PIs) were foot orthoses and added stretching. Both AIs and PIs decreased pain significantly (SMD -0.94, 95% CI -1.35, -0.54 and SMD -1.4, 95% CI -1.87, -0.92). The AIs reduced pain level better than PIs. Controversially, no treatment was found to affect navicular drop. CONCLUSION:Both exercise and foot orthoses can reduce pain but not realign foot posture. Exercise alone or combined with foot orthoses showed a better effect on adult flatfoot than only wearing foot orthoses. Active intervention was shown to have better efficacy in reducing pain than passive intervention. 10.3390/ijerph18158063
The typically developing pediatric foot - The data of the 1744 children in China. Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:The medial longitudinal arch (MLA) improves with age in childhood. However, it still causes parents to worry that children have flat feet. Due to the lack of a standard to quantitatively assess the arch development in kids at certain age, the pediatricians judge the flat feet by experience, causing many cases to be overtreated. The aim of this study was to plot the distribution of MLA parameters in children. METHODS:Children without lower limb deformity and lower limb pain were recruited from 12 primary schools and kindergartens in Chongqing province-level city. Foot length (FL) and navicular height (NH) was measured manually, arch index (AI) and arch volume (AV) were measured with the Foot Plantar Scanner. Each parameter was measured in both weight-bearing and non-weight-bearing positions. Significant differences were also compared between the measurements of consecutive years. RESULTS:This study was the first to use a three-dimensional laser surface scanner to measure the MLA parameters of children aged 3-12 years in China. 1744 children (871 girls, 873 boys) participated in this study. FL, NH, AI and AV varied significantly with age in both the weight-bearing and non-weight-bearing positions. These parameters have significant differences between the weighted and non-weighted positions (p < 0.05). CONCLUSIONS:The age distribution characteristics of these parameters indicated that the MLA improves with age. The establishment of a developmental scale for the children's MLA is necessary. 10.1016/j.fas.2021.04.005
Assessment of the Foot's Longitudinal Arch by Different Indicators and Their Correlation with the Foot Loading Paradigm in School-Aged Children: A Cross Sectional Study. Szczepanowska-Wołowiec Beata,Sztandera Paulina,Kotela Ireneusz,Zak Marek International journal of environmental research and public health BACKGROUND:There are numerous studies assessing the morphological structure of the foot, but there is a notable scarcity of those focused on juxtaposing various longitudinal arch indices with foot loading paradigm. The present study aimed to determine the overall reliability, diagnostic accuracy of respective variables, and their correlation with the foot loading paradigm. METHODS:The study group consisted of 336 children, aged 10-15 years (girls 49.1% and boys 50.9%). The morphological structure of the plantar part of the foot in static conditions was assessed with the aid of a 2D podoscan. Individual foot loading paradigm in static conditions was assessed making use of the FreeMed platform. RESULTS:Staheli (SI), Chippaux-Smirak (CSI), and Sztriter-Godunow (KY) indices were strongly correlated with each other (ρ > 0.84, < 0.001). Own research corroborated an increased pressure of hollow feet, as assessed by the SI, CSI, and KY indices, on the forefoot and the hindfoot, foot zones B, E, F; these correlations being statistically significant. The results yielded by the present study also indicate an increased pressure on the metatarsal, and foot zones C, D of the flat feet. CONCLUSIONS:Flatfootedness is not believed to be a common deformity among children and adolescents. The SI, CSI, and KY indices were found to be strongly correlated, as well as proved reliable in assessing the foot's longitudinal arch. 10.3390/ijerph18105196
Does tibialis posterior dysfunction correlate with a worse radiographic overall alignment in progressive collapsing foot deformity? A retrospective study. Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Posterior Tibial Tendon (PTT) dysfunction is considered to have an important role in Progressive Collapsing Foot Deformity (PCFD). The objective of our study was to assess the relationship between PTT status and three-dimensional foot deformity in PCFD. METHODS:Records from 25 patients with PCFD were included for analysis. The PTT was considered deficient in patients with a positive single heel rise test or a deficit in inversion strength. Three-dimensional foot deformity was assessed using the Foot and Ankle Offset (FAO) from Weight-Bearing-CT imaging. Hindfoot valgus, midfoot abduction and medial longitudinal arch collapse were assessed on X-Rays using hindfoot moment arm, talonavicular coverage angle and Meary's angle respectively. Deland and Rosenberg MRI classifications were used to classify PTT degeneration. RESULTS:PCFD with PTT deficit (13/25) had a mean FAO of 7.75 + /- 3.8% whereas PCFD without PTT deficit had a mean FAO of 6.68 + /- 3.9% (p = 0.49). No significant difference was found between these groups on the hindfoot moment arm and the talonavicular coverage angle (respectively p = 0.54 and 0.32), whereas the Meary's angle was significantly higher in case of PCFD with PTT deficit (p = 0.037). No significant association was found between PTT degeneration on MRI and FAO. CONCLUSION:PCFD associated three-dimensional deformity, hindfoot valgus and midfoot abduction were not associated with PTT dysfunction. PTT dysfunction was only associated with a worse medial longitudinal arch collapse in our study. Considering our results, it does not appear that PTT is the main contributor to PCFD. LEVEL OF EVIDENCE:Level III, Retrospective Comparative Study. 10.1016/j.fas.2022.02.004
Foot orthoses for flexible flatfeet in children and adults: a systematic review and meta-analysis of patient-reported outcomes. BMC musculoskeletal disorders BACKGROUND:This systematic review and meta-analysis examined the effectiveness of orthoses for flexible flatfeet in terms of patient-reported outcomes in children and adults. METHODS:EMBASE, Medline (OvidSP), Web-of-Science, Scopus, CINAHL, Cochrane Central Register of Controlled Clinical Trials, i.e., Cochrane Central and Pubmed were searched to identify relevant studies since their inception up to February 2021. We included randomized controlled trials (RCT) and prospective studies in which patient reported outcomes at baseline and follow-up in an orthoses group were compared with a no orthoses or sham sole group. Methodological quality of the studies was assessed using the Revised Cochrane risk-of-bias tool for randomized trials (RoB 2) and the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I). A meta-analysis was performed where there were multiple studies with the same outcome measures, which was the case for the Visual Analogue Scale (VAS) for pain in adults. RESULTS:In total nine studies were included: four RCT in children (N = 353) and four RCT and one prospective study in adults (N = 268) were included. There was considerable heterogeneity between studies. A meta-analysis demonstrated that pain reduction between baseline and follow-up was significantly larger in the orthoses (N = 167) than in the control groups in adults (N = 157; - 4.76, 95% CI [- 9.46, - 0.06], p0.05). CONCLUSION:Due to heterogeneity in study designs, we cannot conclude that foot orthoses are useful for flexible flatfoot in children and adults. However, based on the meta-analysis orthoses might be useful in decreasing pain in adults. The authors did not receive support from any organization for the submitted work. 10.1186/s12891-022-06044-8
Prevalence and pattern of lateral impingements in the progressive collapsing foot deformity. Archives of orthopaedic and trauma surgery INTRODUCTION:The prevalence of lateral bony impingements [i.e., Sinus Tarsi (STI), Talo-Fibular (TFI) and Calcaneo-Fibular (CFI)] and their association with Peritalar Subluxation (PTS) have not been clearly established for progressive collapsing foot deformity (PCFD).This study aims to assess the prevalence of STI, TFI and CFI in PCFD, in addition to their association with PTS. We hypothesized that STI and TFI would be more prevalent than CFI. MATERIALS AND METHODS:Seventy-two continuous symptomatic PCFD cases were retrospectively reviewed. Weightbearing computed tomography (WBCT) was used to assess lateral impingements and classified as STI, TFI and CFI. PTS was assessed by the percent of uncovered and the incongruence angle of the middle facet, and the overall foot deformity was determined by the foot and ankle offset (FAO). Data were collected by two fellowship-trained independent observers. RESULTS:Intra-observer and inter-observer reliabilities for impingement assessment ranged from substantial to almost perfect. STI was present in 84.7%, TFI in 65.2% and CFI in 19.4%. PCFD with STI showed increased middle facet uncoverage (p = 0.0001) and FAO (p = 0.0008) compared to PCFD without STI. There were no differences in FAO and middle facet uncoverage in PCFD with TFI and without TFI. PCFD with CFI was associated with STI in 100% of cases. PCFD with CFI showed decreased middle facet incongruence (p = 0.04) and higher FAO (p = 0.006) compared to PCFD without CFI. CONCLUSIONS:STI and TFI were more prevalent than CFI in PCFD. However, only STI was associated with PTS. Conversely, CFI was associated with less PTS, suggesting a different pathological mechanism which could be a compensatory subtalar behavior caused by deep layer failure of the deltoid ligament and talar tilt. 10.1007/s00402-021-04015-7
Indications for Deltoid and Spring Ligament Reconstruction in Progressive Collapsing Foot Deformity. Foot & ankle international RECOMMENDATION:There is evidence supporting medial soft tissue reconstruction, such as spring and deltoid ligament reconstructions, in the treatment of severe progressive collapsing foot deformity (PCFD). We recommend spring ligament reconstruction to be considered in addition to lateral column lengthening or subtalar fusion at the initial operation when those procedures have given at least 50% correction but inadequate correction of the severe flexible subluxation of the talonavicular and subtalar joints. We also recommend combined flatfoot reconstruction and deltoid reconstruction be considered as a joint sparing alternative in the presence of PCFD with valgus deformity of the ankle joint if there is 50% or more of the lateral joint space remaining. LEVEL OF EVIDENCE:Level V, expert opinion. 10.1177/1071100720950742
The effects of foot orthosis and low-dye tape on lower limb joint angles and moments during running in individuals with pes planus. Gait & posture BACKGROUND:Pes Planus or Flat feet is one of the most common lower limb abnormalities. When runners with this abnormality participate in recreational running, interventional therapies could help in pain alleviation and enhance performance. To determine the most effective treatment, however, a biomechanical examination of the effects of each treatment modality is required. RESEARCH QUESTION:The aim of the present study was to investigate the effects of Foot Orthoses (FOs) and Low-Dye Tape (LDT) on lower limb joint angles and moments during running in individuals with pes planus. METHODS:kinematic and kinetic data of 20 young people with pes planus were measured during running in three conditions: (1) SHOD (2) with shoes and FOs (3) with shoes and LDT. One-way repeated measure ANOVA was used to investigate the impacts of the FOs and LDT on the lower limb joint angles and moments throughout the stance phase of the running cycle. RESULTS:The results showed that FOs reduced ankle eversion compared to SHOD and LDT (P < 0.001) and decreased the dorsiflexion angle (P = 0.005) and the plantarflexor moment compared to the SHOD (P < 0.001). FOs increased knee adduction angle (P = 0.021) and knee external rotator moment (P < 0.001) compared to both conditions and increased knee extensor and abductor moments compared to SHOD (P < 0.001). At the hip joint, FOs only increased hip external rotation compared with the LDT condition (P = 0.031); and LDT increased hip extensor moment compared to SHOD and FOs (P = 0.037) and also increased hip adduction angle compared to SHOD (P = 0.037). SIGNIFICANCE:FOs with a medial wedge appears to increase the external knee adduction moment and knee adduction angles, which are risk factors for the development and progression of knee osteoarthritis. Further, usage of FOs seems to reduce the ankle joint role in propulsion as it impacts the ankle sagittal angles and moments. 10.1016/j.gaitpost.2022.05.024
Consensus for the Use of Weightbearing CT in the Assessment of Progressive Collapsing Foot Deformity. Foot & ankle international RECOMMENDATION:There is evidence that the use of imaging aids in the assessment of progressive collapsing foot deformity (PCFD). The following conventional radiographs (CRs) are necessary in the assessment of PCFD patients: anteroposterior (AP) foot, AP or mortise ankle, and lateral foot. If available, a hindfoot alignment view is strongly recommended. If available, computed tomography (CT) is strongly recommended for surgical planning. When CT is obtained, important findings to be assessed are sinus tarsi impingement, subfibular impingement, increased valgus inclination of the posterior facet of the subtalar joint, and subluxation of the subtalar joint at the posterior and/or middle facet. LEVEL OF EVIDENCE:Level V, consensus, expert opinion. 10.1177/1071100720950734
Foot orthoses alter lower limb biomechanics but not jump performance in basketball players with and without flat feet. Journal of foot and ankle research BACKGROUND:Flat-footed individuals are believed to have poorer jump performance compared to normal-arched individuals. Foot orthoses are commonly used to support the deformed foot arch, and improve normal foot function. However, it is unclear if foot orthoses use affects jump performance in athletes. Our study aims to investigate if foot type and/or foot orthosis influence countermovement jump (CMJ) and standing broad jump (SBJ) performance and lower limb biomechanics. METHODS:Twenty-six male basketball players were classified into normal-arched ( = 15) or flat-footed ( = 11) groups using the Chippaux-Smirak index, navicular drop test, and the resting calcaneal angle measurement. They performed jumps with and without prefabricated foot orthoses. We measured jump height and distance for CMJ and SBJ, respectively. Hip, knee and ankle joint angles, angular velocities, moments and powers during take-off were also measured. RESULTS:For CMJ, the flat-footed group exhibited less ankle plantarflexion (  = 8.407,  = 0.008,  = 0.259 large effect) and less hip joint power (  = 7.416,  = 0.012,  = 0.244 large effect) than the normal-arched group. Foot orthoses reduced ankle eversion in both groups (  = 6.702,  = 0.016,  = 0.218 large effect). For SBJ, the flat-footed group produced lower peak hip angular velocity (  = 7.115,  = 0.013,  = 0.229 large effect) and generated lower horizontal GRF (  = 5.594,  = 0.026,  = 0.189 large effect) than the normal-arched group. Wearing foot orthoses reduced ankle eversion (  = 5.453,  = 0.028,  = 0.185 large effect), peak horizontal GRF (  = 13.672,  = 0.001,  = 0.363 large effect) and frontal plane ankle moment (  = 4.932,  = 0.036,  = 0.170 large effect). CONCLUSION:Foot type and the use of foot orthoses influence take-off biomechanics, but not actual CMJ and SBJ performances in basketball players. Compared to the normal-arched individuals, flat-footed athletes generated smaller propulsion GRF and lower hip flexion velocity and power, which suggests possible compensatory movement strategies to maximise jump performance. Future studies may investigate whether these altered biomechanics, taking into consideration their respective magnitude and effect sizes, may have implications on lower limb injuries. The use of foot orthoses resulted in biomechanical changes in both the normal-arched and flat-footed groups but does not enhance jumping performance. 10.1186/s13047-019-0334-1
Classification and Nomenclature: Progressive Collapsing Foot Deformity. Foot & ankle international RECOMMENDATION:The historical nomenclature for the adult acquired flatfoot deformity (AAFD) is confusing, at times called posterior tibial tendon dysfunction (PTTD), the adult flexible flatfoot deformity, posterior tibial tendon rupture, peritalar instability and peritalar subluxation (PTS), and progressive talipes equinovalgus. Many but not all of these deformities are associated with a rupture of the posterior tibial tendon (PTT), and some of these are associated with deformities either primarily or secondarily in the midfoot or ankle. There is similar inconsistency with the use of classification schemata for these deformities, and from the first introduced by Johnson and Strom (1989), and then modified by Myerson (1997), there have been many attempts to provide a more comprehensive classification system. However, although these newer more complete classification systems have addressed some of the anatomic variations of deformities encountered, none of the above have ever been validated. The proposed system better incorporates the most recent data and understanding of the condition and better allows for standardization of reporting. In light of this information, the consensus group proposes the adoption of the nomenclature "Progressive Collapsing Foot Deformity" (PCFD) and a new classification system aiming at summarizing recent data published on the subject and to standardize data reporting regarding this complex 3-dimensional deformity. LEVEL OF EVIDENCE:Level V, consensus, expert opinion. CONSENSUS STATEMENTS VOTED: We will rename the condition to Progressive Collapsing Foot Deformity (PCFD), a complex 3-dimensional deformity with varying degrees of hindfoot valgus, forefoot abduction, and midfoot varus.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus) Our current classification systems are incomplete or outdated.Delegate vote: agree, 100% (9/9); disagree, 0%; abstain, 0%.(Unanimous, strongest consensus) MRI findings should be part of a new classification system.Delegate vote: agree, 33% (3/9); disagree, 67% (6/9); abstain, 0%.(Weak negative consensus) Weightbearing CT (WBCT) findings should be part of a new classification system.Delegate vote: agree, 56% (5/9); disagree, 44% (4/9); abstain, 0%.(Weak consensus) A new classification system is proposed and should be used to stage the deformity clinically and to define treatment.Delegate vote: agree, 89% (8/9); abstain, 11% (1/9).(Strong consensus). 10.1177/1071100720950722
Validity of a simple footprint assessment board for diagnosing the severity of flatfoot: a prospective cohort study. BMC musculoskeletal disorders BACKGROUND:A simple, non-quantitative, and cost-effective diagnostic tool would enable the diagnosis of flatfoot without need for specialized training. A simple footprint assessment board that investigates which toe the cord passes through from the centre point of the heel to the most lateral point of the medial contour of the footprint has been developed to assess flatfoot. The purpose of this study was to verify the validity of a simple footprint assessment board for flatfoot. METHODS:Thirty-five consecutive patients with foot pain, foot injury, or any associated symptoms who underwent computed tomography (CT) were analysed prospectively. At the time of the CT scan, a footprint analysis using a simple footprint assessment board was performed. The navicular index, tibiocalcaneal angle, and calcaneal inclination angle were evaluated by CT to assess flat feet. These three criteria were compared to those evaluated with the simple footprint assessment board by regression analysis. In addition, the same analysis was conducted separately for young, middle-aged, and older patients in order to investigate each age group. RESULTS:The navicular index and tibiocalcaneal angle generally decreased as the score of the simple footprint assessment board increased. Calcaneal inclination angle generally increased as the score of the simple footprint assessment board increased. As the scores of the simple footprint assessment board decreased by approaching the great toe, the navicular index and tibiocalcaneal angle were higher and calcaneal inclination angle was lower, which is indicative of a higher likelihood of flatfoot. The scores derived from the simple footprint assessment board was correlated with these three criteria measured by CT, not only when the result of simple footprint assessment board was set as a non-continuous variable but also when the result was set as a continuous variable. The results of the age-stratified survey were similar for all groups. CONCLUSIONS:The findings of this study suggest that a simple footprint assessment board can be potentially useful to detect flatfoot. TRIAL REGISTRATION:Retrospectively registered. 10.1186/s12891-021-04154-3
The role of medial ligaments and tibialis posterior in stabilising the medial longitudinal foot arch: a cadaveric gait simulator study. Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Debate exists whether adult acquired flatfoot deformity develops secondary to tibialis posterior (TibPost) tendon insufficiency, failure of the ligamentous structures, or a combination of both. AIM:The aim of this study is to determine the contribution of the different medial ligaments in the development of acquired flatfoot pathology. Also to standardise cadaveric flatfoot models for biomechanical research and orthopaedic training. METHODS:Five cadaveric feet were tested on a dynamic gait simulator. Following tests on the intact foot, the medial ligaments - fascia plantaris (FP), the spring ligament complex (SLC) and interosseous talocalcaneal ligament (ITCL) - were sectioned sequentially. Joint kinematics were analysed for each condition, with and without force applied to TibPost. RESULTS:Eliminating TibPost resulted in higher internal rotation of the calcaneus following the sectioning of FP and SLC (d>1.28, p = 0.08), while sectioning ITCL resulted in higher external rotation without TibPost (d = 1.24, p = 0.07). Sequential ligament sectioning induced increased flattening of Meary's angle. CONCLUSION:Function of TibPost and medial ligaments is not mutually distinctive. The role of ITCL should not be neglected in flatfoot pathology; it is vital to section this ligament to develop flatfoot in cadaveric models. 10.1016/j.fas.2021.12.005
Is it possible to define reference values for radiographic parameters evaluating juvenile flatfoot deformity? A case-control study. Hamel Johannes,Hörterer Hubert,Harrasser Norbert BMC musculoskeletal disorders BACKGROUND:Numerous radiographic parameters are described to evaluate juvenile flexible flatfeet. Reference values for these measurements are based on few studies. The purpose of this study was to determine boundary values among the most widely used radiographic measurements to evaluate juvenile flatfeet. METHODS:Twenty-two patients with normal hind-, midfoot configuration (group A: control group; 22 ft, mean age: 12,1 years) and 19 patients with flatfoot deformity (group B: study group; 22 ft, mean age: 12,4 years) were retrospectively analyzed. Nine radiographic parameters were measured (Talocalcaneal-angles, Calcaneal-pitch-angle, Costa-Bartani-angle, Talo-metatarsal-I-angles, Talo-first-metatarsal-base-angle, Talo-navicular-coverage, Calcaneus-fifth-metatarsal-angle). ROC curve analysis was used to calculate optimal differentiating thresholds of each parameter. RESULTS:Four out of nine parameters (TC-dp, TC-lat, Calc-MTV, Calc-P) were not statistically different between the groups and their ability to distinct between normal foot and flatfoot was low (AUC values = 0,660 - 0,819). Calculation of reference values for these parameters was not performed due to threshold ranges between the groups of > 10°. Reference values could be defined only for three parameters: TMTInd >(-)31°, TMTIB >(-)7,5°, TMT-lat > (-)13,5°. The TMTInd was shown to be a very reliable and valid combination of two measurements (TMTIB and TMT-lat) in the differentiation of normal feet and flatfeet (AUC = 0,998). CONCLUSION:The calculation of reference values for established radiographic parameters used to evaluate juvenile flatfeet is difficult for most parameters. The TMTInd as a combination of TMTIB and TMT-lat has been shown to be reliable and valuable to distinct normal feet from flatfeet. 10.1186/s12891-020-03854-6
Postural Stability and Muscle Activation Onset during Double- to Single-Leg Stance Transition in Flat-Footed Individuals. Koshino Yuta,Samukawa Mina,Chida Shuya,Okada Shinpei,Tanaka Hirono,Watanabe Kentaro,Chijimatsu Masato,Yamanaka Masanori,Tohyama Harukazu Journal of sports science & medicine The effects of foot posture on postural stability and on muscular activation pattern for postural control remain unclear. This study aimed to investigate postural stability and muscular activation onset during the transition task from double- to single-leg stance in individuals with different foot postures. Twenty-seven healthy men (age: 21.5 ± 1.5 years) were divided into 3 groups using the Foot Posture Index: neutral foot (n = 10); flatfoot (n = 8); and high-arched foot (n = 9). Center of pressure (COP) data and muscle activation onset times of the tibialis anterior, peroneus longus, gastrocnemius medialis, and soleus during the transition task with eyes closed were compared among groups using one-way analysis of variance and a post-hoc Tukey honestly significant difference test (p < 0.05) when the data were normally distributed and the Kruskal-Wallis test and a post-hoc Mann-Whitney U-test with Bonferroni correction (p < 0.0167) when the data were not normally distributed. The COP displacements in the mediolateral and anteroposterior directions and the resultant COP displacement during the first 3 s after a stability time point, as determined by sequential estimation during the single-leg stance phase, differed significantly among the three groups (p < 0.05). Post-hoc tests showed that the displacements were significantly greater in the flatfoot group than in the neutral and high-arched foot groups (p < 0.05), and the effect sizes for these results were large. No muscular activation onset times showed significant intergroup differences. Postural stability was significantly decreased only in the flatfoot group, while muscle activation onsets did not differ significantly by foot posture during the transition task. Decreased postural stability may be one mechanism underlying the link between flatfoot and risk of lower limb injury, and foot posture represents a potential confounder for measuring postural stability during the transition task.
Association of bilateral flat feet with knee pain and disability in patients with knee osteoarthritis: A cross-sectional study. Iijima Hirotaka,Ohi Hiroshi,Isho Takuya,Aoyama Tomoki,Fukutani Naoto,Kaneda Eishi,Ohi Kazuko,Abe Kaoru,Kuroki Hiroshi,Matsuda Shuichi Journal of orthopaedic research : official publication of the Orthopaedic Research Society This cross-sectional study examined the relationship of flat feet with knee pain, disability, and physical performance in patients with knee osteoarthritis (OA). Orthopedic clinic participants (n = 95; age 61-91 years; 68.4% women) with Kellgren-Lawrence (K/L) grade ≥1 in the medial compartment underwent evaluation of navicular height and foot length for flat feet. Knee pain intensity, disability, and physical performance were evaluated using the Japanese Knee Osteoarthritis Measure, 10-m walk, timed up and go, and five-repetition chair stand tests. Of the 95 enrolled patients, 24 (25.3%) had bilateral flat feet, and significantly higher knee pain compared to patients with no flat feet (11.3 ± 8.23 points vs. 6.58 ± 6.37 points; p = 0.043). A ordinal logistic regression analysis showed that bilateral flat feet were significantly associated with increased knee pain (proportional odds ratio: 5.48, 95% confidence interval: 1.96, 15.3; p = 0.001) compared with no flat feet, adjusted for age, sex, body mass index, and tibiofemoral joint K/L grade, which is consistent across various different cutoffs of the definition of flat feet. Physical performance was similar between patients with and without bilateral flat feet. The presence of unilateral flat feet was not significantly associated with any outcome measures. These findings indicate that bilateral, but not unilateral, flat feet are associated with worse knee pain. A prospective study investigating a causal relationship between bilateral flat feet posture and knee pain as well as disability would be of particular interest to verify the potential adverse effect of altered foot posture. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2490-2498, 2017. 10.1002/jor.23565
Return to Physical Activity Following Flatfoot Reconstruction. Foot & ankle international BACKGROUND:Progressive collapsing foot deformity (PCFD) is a debilitating condition encompassing several interrelated, progressive deformities requiring a combination of reconstructive procedures. Few studies investigate returns to activity following flatfoot reconstruction, and existing studies only examine 1 or 2 of the numerous procedures employed. This study aims to provide the first generalizable assessment of returns to sports and physical activity following reconstruction surgery in patients with flexible flatfoot deformity. METHODS:Patients aged 18-60 years who underwent reconstructive surgery between February 16 and May 19 for symptomatic flexible-stage flatfoot deformity were identified by registry review. Eighty-two of 113 eligible patients (73%) were reached at a mean 2.9 years (range, 2.0-5.4) of follow-up with mean age at surgery of 48.9 years (range, 18-59). Returns to physical activity were evaluated with a sports-specific survey. Clinical outcomes were evaluated with Patient-Reported Outcomes Measurement Information System (PROMIS) scores. RESULTS:Patients reported participation in 21 specific sports and activities. One-fourth (25.6%) of patients (21/82) reported increased difficulty with physical activities postoperatively, 15.9% reported equal difficulty, and 58.5% (48/82) reported decreased difficulty. Median return times were 9-12 months for participation and 12-18 months to reach maximum preoperative participation levels. Improvements in Physical Function (= .001), Pain Interference ( < .001), Pain Intensity ( <.001), and Global Physical Health ( = .004) were associated with increased satisfaction with respect to sports and physical activities. DISCUSSION:This study investigated participation in specific sports and physical activities following flatfoot reconstruction. Our findings suggest mixed outcomes, where many patients reported life-changing improvements but many also experienced prolonged pain and difficulty after surgery. Some patients reported increased difficulty or inability to return to their preoperative maximum level of participation, indicating that flatfoot reconstructions can lead to athletic limitations. CONCLUSION:Although flatfoot reconstruction can be a powerful tool to increase patients' capacity to engage in physical activity, in our cohort many patients had reduced physical activity outcomes. LEVEL OF EVIDENCE:Level IV, retrospective case series. 10.1177/10711007221077098
The contribution of the ligaments in progressive collapsing foot deformity: A comprehensive computational study. Journal of orthopaedic research : official publication of the Orthopaedic Research Society The contribution of each of the ligaments in preventing the arch loss, hindfoot valgus, and forefoot abduction seen in progressive collapsing foot deformity (PCFD) has not been well characterized. An improved understanding of the individual ligament contributions to the deformity would aid in selecting among available treatments, optimizing current surgical techniques, and developing new ones. In this study, we evaluated the contribution of each ligament to the maintenance of foot alignment using a finite element model of the foot reconstructed from computed tomography scan images. The collapsed foot was modeled by simulating the failure of all the ligaments involved in PCFD. The ligaments were removed one at a time to determine the impact of each ligament on foot alignment, and then restored one at a time to simulate isolated reconstruction. Our findings show that the failure of any one ligament did not immediately lead to deformity, but that combined failure of only a few (the plantar fascia, long plantar, short plantar, deltoid, and spring ligaments) could lead to significant deformity. The plantar fascia, deltoid, and spring ligaments were primarily responsible for the prevention of arch collapse, hindfoot valgus, and forefoot abduction, respectively. Moreover, to produce deformity, a considerable amount of attenuation in the spring, tibiocalcaneal, interosseous talocalcaneal, plantar naviculocuneiform, and first plantar tarsometatarsal ligaments, but only a small amount in the plantar fascia, long plantar, and short plantar ligaments was needed. The results of this study suggest that the ability of a ligament to prevent deformity may not correlate with its attenuation in a collapsed foot. 10.1002/jor.25244
Effect of Obesity on Clinical and Radiographic Outcomes Following Reconstruction of Stage II Adult Acquired Flatfoot Deformity. Soukup Dylan S,MacMahon Aoife,Burket Jayme C,Yu Jeanne M,Ellis Scott J,Deland Jonathan T Foot & ankle international BACKGROUND:Obesity is a known risk factor for the development of adult acquired flatfoot deformity (AAFD), but obesity's effects on outcomes following AAFD reconstruction are unknown. We hypothesized that obesity would negatively impact outcomes following joint-preserving stage II AAFD reconstruction. METHODS:This retrospective study compared the outcomes of normal-weight (18.5 kg/m(2) ≤ BMI < 25 kg/m(2)), overweight (25 kg/m(2) ≤ BMI < 30 kg/m(2)), and obese (BMI ≥ 30 kg/m(2)) patients after AAFD reconstruction. Clinical outcome measures included the Foot and Ankle Outcome Score (FAOS), Short-Form 12 (SF-12), and Numeric Rating Scale of Pain (NRS Pain) administered preoperatively and at least 1 year postoperatively. Anteroposterior and lateral radiographs were taken preoperatively and at least 6 months postoperatively. Pre- to postoperative changes in outcome measures were assessed within BMI classes. Preoperative, postoperative, and pre- to postoperative changes in outcomes were compared among BMI classes. There were 41 normal-weight patients, 39 overweight patients, and 44 obese patients with a mean age of 56 years, FAOS follow-up of 2.9 years, and radiographic follow-up of 2.1 years. Demographics and reconstructive procedures were comparable among the 3 BMI classes. RESULTS:All outcomes significantly increased pre- to postoperatively in the 3 groups with the exception of the FAOS Symptoms subscale for normal-weight patients (P = .340) and SF-12 Mental Component score for all 3 BMI classes (P > .999). Preoperatively, obese patients had more symptoms than normal-weight patients, scoring 12 points lower on the FAOS Symptoms subscore (P = .008). Obese patients also scored 11 points lower preoperatively on the SF-12 Overall score (P = .028) and had 31% greater pain than normal-weight patients (P = .003). There were no differences among the 3 BMI classes in any postoperative outcomes assessed. CONCLUSION:Although obese patients had significantly worse symptoms, overall health, and NRS pain scores preoperatively, the short-term clinical and radiographic outcomes of stage II AAFD reconstruction were similar for normal-weight, overweight, and obese patients. We suggest that joint-preserving reconstruction remains a viable alternative to fusion of the triple joint complex for the treatment of overweight and obese stage II AAFD patients. LEVEL OF EVIDENCE:Level III, retrospective cohort study. 10.1177/1071100715614841
A novel implantable mechanism-based tendon transfer surgery for adult acquired flatfoot deformity: Evaluating feasibility in biomechanical simulation. PloS one Adult acquired flatfoot deformity becomes permanent with stage III posterior tibialis tendon dysfunction and results in foot pain and difficulty walking and balancing. To prevent progression to stage III posterior tibialis tendon dysfunction when conservative treatment fails, a flexor digitorum longus to posterior tibialis tendon transfer is often conducted. However, since the flexor digitorum longus only has one-third the force-capability of the posterior tibialis, an osteotomy is typically also required. We propose the use of a novel implantable mechanism to replace the direct attachment of the tendon transfer with a sliding pulley to amplify the force transferred from the donor flexor digitorum longus to the foot arch. In this work, we created four OpenSim models of an arched foot, a flatfoot, a flatfoot with traditional tendon transfer, and a flatfoot with implant-modified tendon transfer. Paired with these models, we developed a forward dynamic simulation of the stance phase of gait that reproduces the medial/lateral distribution of vertical ground reaction forces. The simulation couples the use of a fixed tibia, moving ground plane methodology with simultaneous activation of nine extrinsic lower limb muscles. The arched foot and flatfoot models produced vertical ground reaction forces with the characteristic double-peak profile of gait, and the medial/lateral distribution of these forces compared well with the literature. The flatfoot model with implant-modified tendon transfer produced a 94.2% restoration of the medial/lateral distribution of vertical ground reaction forces generated by our arched foot model, which also represents a 2.1X improvement upon our tendon transfer model. This result demonstrates the feasibility of a pulley-like implant to improve functional outcomes for surgical treatment of adult acquired flatfoot deformity with ideal biomechanics in simulation. The real-world efficacy and feasibility of such a device will require further exploration of factors such as surgical variability, soft tissue interactions and healing response. 10.1371/journal.pone.0270638
Biomechanical assessment of flexible flatfoot correction: comparison of techniques in a cadaver model. Zanolli Diego H,Glisson Richard R,Nunley James A,Easley Mark E The Journal of bone and joint surgery. American volume BACKGROUND:Options for surgical correction of acquired flexible flatfoot deformity involve bone and soft-tissue reconstruction. We used an advanced cadaver model to evaluate the ability of key surgical procedures to correct the deformity and to resist subsequent loss of correction. METHODS:Stage-IIB flatfoot deformity was created in ten cadaver feet through ligament sectioning and repetitive loading. Six corrective procedures were evaluated: (1) lateral column lengthening, (2) medial displacement calcaneal osteotomy with flexor digitorum longus transfer, (3) Treatment 2 plus lateral column lengthening, (4) Treatment 3 plus "pants-over-vest" spring ligament repair, (5) Treatment 3 plus spring ligament repair with use of the distal posterior tibialis stump, and (6) Treatment 3 plus spring ligament repair with suture and anchor. Correction of metatarsal dorsiflexion and of navicular eversion were quantified initially and periodically during postoperative cyclic loading. RESULTS:Metatarsal dorsiflexion induced by arch flattening was initially corrected by 5.5° to 10.6°, depending on the procedure. Navicular eversion was initially reduced by 2.1° to 7.7°. The correction afforded by Treatments 1, 3, 4, 5, and 6 exceeded that of Treatment 2 initially and throughout postoperative loading. Inclusion of spring ligament repair did not significantly enhance correction. CONCLUSIONS:Under the tested conditions, medial displacement calcaneal osteotomy with flexor digitorum longus tendon transfer was inferior to the other evaluated treatments for stage-IIB deformity. Procedures incorporating lateral column lengthening provided the most sagittal and coronal midfoot deformity correction. Addition of spring ligament repair to a combination of these three procedures did not substantially improve correction. CLINICAL RELEVANCE:An understanding of treatment effectiveness is essential for optimizing operative management of symptomatic flatfoot deformity. This study provides empirical evidence of the advantage of lateral column lengthening and novel information on resistance to postoperative loss of correction. 10.2106/JBJS.L.00258
Isolated spring ligament rupture causing acute flatfoot deformity: case report. Weerts Bas,Warmerdam Piet E,Faber Frank W M Foot & ankle international 10.3113/FAI.2012.0148
Foot posture is associated with kinematics of the foot during gait: A comparison of normal, planus and cavus feet. Buldt Andrew K,Levinger Pazit,Murley George S,Menz Hylton B,Nester Christopher J,Landorf Karl B Gait & posture Variations in foot posture are associated with the development of some lower limb injuries. However, the mechanisms underlying this relationship are unclear. The objective of this study was to compare foot kinematics between normal, pes cavus and pes planus foot posture groups using a multi-segment foot model. Ninety-seven healthy adults, aged 18-47 were classified as either normal (n=37), pes cavus (n=30) or pes planus (n=30) based on normative data for the Foot Posture Index, Arch Index and normalised navicular height. A five segment foot model was used to measure tri-planar motion of the rearfoot, midfoot, medial forefoot, lateral forefoot and hallux during barefoot walking at a self-selected speed. Angle at heel contact, peak angle, time to peak angle and range of motion was measured for each segment. One way ANOVAs with post-hoc analyses of mean differences were used to compare foot posture groups. The pes cavus group demonstrated a distinctive pattern of motion compared to the normal and pes planus foot posture groups. Effect sizes of significant mean differences were large and comparable to similar studies. Three key differences in overall foot function were observed between the groups: (i) altered frontal and transverse plane angles of the rearfoot in the pes cavus foot; (ii) Less midfoot motion in the pes cavus foot during initial contact and midstance; and (iii) reduced midfoot frontal plane ROM in the pes planus foot during pre-swing. These findings indicate that foot posture does influence motion of the foot. 10.1016/j.gaitpost.2015.03.004
The effect of a 12-week custom foot orthotic intervention on muscle size and muscle activity of the intrinsic foot muscle of young adults during gait termination. Protopapas Katrina,Perry Stephen D Clinical biomechanics (Bristol, Avon) BACKGROUND:The tissue stress theory is commonly used to prescribe foot orthoses, however the mechanisms of foot orthoses are not understood well. The effect foot orthotics have on the plantar intrinsic muscles remains unclear. The study was designed to assess changes in muscle size and activity of the intrinsic muscles of individuals with pes planus after wearing custom-made foot orthotics for 12-weeks. METHODS:Eighteen young adults with pes planus were allocated by stratified sampling into the orthotic group (n = 9) or control group (n = 9). Ultrasonography measured the cross-sectional area of the flexor digitorum brevis, abductor digiti minimi, and abductor hallucis at baseline, 6 and 12-weeks. Subsequently, participants completed an unexpected gait termination protocol (12 of 50 trials unexpected) and average electromyography magnitude was recorded. FINDINGS:After 12-weeks the orthotic group cross-sectional area significantly decreased by 9.6% (P < .001) for the flexor digitorum brevis, 17.1% for abductor digiti minimi (P < .001) and 17.4% for abductor hallucis (P < .001). There were no significant differences of muscle activity magnitude for the intrinsic muscles. INTERPRETATION:The short-term use of custom-made foot orthoses created a decrease in muscle size of the flexor digitorium brevis, abductor digiti minimi and abductor hallucis plantar intrinsic muscles but had no effect on muscle activity. Clinically, these results help to understand the adaptations that are created when foot orthoses are supporting a pes planus foot structure when reducing plantar pressures. These findings may help enhance the prescription of foot orthoses by adding a strength program to prevent disuse atrophy of these muscles. 10.1016/j.clinbiomech.2020.105063
Finite element analysis of secondary effect of midfoot fusions on the spring ligament in the management of adult acquired flatfoot. Cifuentes-De la Portilla Christian,Pasapula Chandra,Larrainzar-Garijo Ricardo,Bayod Javier Clinical biomechanics (Bristol, Avon) BACKGROUND:Surgical treatment of adult acquired flatfoot deformity can involve arthrodesis of the midfoot to stabilize the medial column. Few experimental studies have assessed the biomechanical effects of these fusions, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by various types of midfoot arthrodesis on the Spring ligament. To date this is not known. METHODS:An innovative finite element model was used to evaluate flatfoot scenarios treated with various combinations of midfoot arthrodesis. All the bones, cartilages and tissues related to adult acquired flatfoot deformity were included, respecting their biomechanical characteristics. The stress changes on the Spring ligament were quantified. Both foot arch lengthening and falling were measured for each of the midfoot arthrodeses evaluated. FINDINGS:Arthrodesis performed for stabilization of the talonavicular joint leads to a higher decrease in stress on the Spring ligament. Talonavicular fusion generated a Spring ligament stress decrease of about 61% with respect to the reference case (without any fusion). However, fusing the naviculocuneiform joints leads to an increase in the stress on the Spring ligament. INTERPRETATION:This important finding has been unknown to date. We advocate caution regarding fusion of the naviculocuneiform joint as it leads to increased stresses across the Spring ligament and therefore accelerates the development of planovalgus. 10.1016/j.clinbiomech.2020.105018
Does excessive flatfoot deformity affect function? A comparison between symptomatic and asymptomatic flatfeet using the Oxford Foot Model. Hösl Matthias,Böhm Harald,Multerer Christel,Döderlein Leonhard Gait & posture Treatment of asymptomatic flexible flatfeet is a subject of great controversy. The purpose of this study was to examine foot function during walking in symptomatic (SFF) and asymptomatic (ASFF) flexible flatfeet. Thirty-five paediatric and juvenile patients with idiopathic flexible flatfeet were recruited from an orthopaedic outpatient department (14 SFF and 21 ASFF). Eleven age-matched participants with typically developing feet served as controls (TDF). To study foot function, 3D multi-segment foot kinematics and ankle joint kinetics were captured during barefoot gait analysis. Overall, alterations in foot kinematics in flatfeet were pronounced but differences between SFF and ASFF were not observed. Largest discriminatory effects between flatfeet and TDF were noticed in reduced hindfoot dorsiflexion as well as in increased forefoot supination and abduction. Upon clinical examination, restrictions in passive dorsiflexion in ASFF and SFF were significant. During gait, the hindfoot in flatfeet (both ASFF and SFF) was more everted, but less flexible. In sagittal plane, limited hindfoot dorsiflexion of ASFF and SFF was compensated for by increased forefoot mobility and a hypermobile hallux. Concerning ankle kinetics, SFF lacked positive joint energy for propulsion while ASFF needed to absorb more negative ankle joint energy during loading response. This may risk fatigue and overuse syndrome of anterior shank muscles in ASFF. Hence, despite a lack of symptoms flatfoot deformity in ASFF affected function. Yet, contrary to what was expected, SFF did not show greater deviations in 3D foot kinematics than ASFF. Symptoms may rather depend on tissue wear and subjective pain thresholds. 10.1016/j.gaitpost.2013.05.017
Biomechanical comparison among five mid/hindfoot arthrodeses procedures in treating flatfoot using a musculoskeletal multibody driven finite element model. Peng Yinghu,Niu Wenxin,Wong Duo Wai-Chi,Wang Yan,Chen Tony Lin-Wei,Zhang Guoxin,Tan Qitao,Zhang Ming Computer methods and programs in biomedicine BACKGROUND AND OBJECTIVE:Mid/hindfoot arthrodesis could modify the misalignment of adult-acquired flatfoot and attenuate pain. However, the long-term biomechanical effects of these surgical procedures remain unclear, and the quantitative evidence is scarce. Therefore, we aimed to investigate and quantify the influences of five mid/hindfoot arthrodeses on the internal foot biomechanics during walking stance. METHODS:A young participant with flexible flatfoot was recruited for this study. We reconstructed a subject-specific musculoskeletal multibody driven-finite element (FE) foot model based on the foot magnetic resonance imaging. The severe flatfoot model was developed from the flexible flatfoot through the attenuation of ligaments and the unloading of the posterior tibial muscle. The five mid/hindfoot arthrodeses simulations (subtalar, talonavicular, calcaneocuboid, double, and triple arthrodeses) and a control condition (no arthrodesis) were performed simultaneously in the detailed foot multibody dynamics model and FE model. Muscle forces calculated by a detailed multi-segment foot model and ground reaction force were used to drive the foot FE model. The internal foot loadings were compared among control and these arthrodeses conditions at the first and second vertical ground reaction force (VGRF) peak and VGRF valley instants. RESULTS:The results indicated that the navicular heights in double and triple arthrodeses were higher than other surgical procedures, while the subtalar arthrodesis had the smallest values. Five mid/hindfoot arthrodeses reduced the peak plantar fascia stress compared to control. However, double and triple arthrodeses increased the peak medial cuneo-navicular joint contact pressures and peak foot pressures as well as the metatarsal bones stresses. CONCLUSION:Although mid/hindfoot arthrodesis generally reduced the collapse of medial longitudinal arch and plantar fascia loading during the stance phase, the increased loading in the adjacent unfused joint and metatarsal bones for double and triple arthrodeses should be noted. These findings could account for some symptoms experienced by flatfoot patients after surgery, which may facilitate the optimization of surgical protocols. 10.1016/j.cmpb.2021.106408
Effect of plano-valgus foot posture on midfoot kinematics during barefoot walking in an adolescent population. Caravaggi Paolo,Sforza Chiarella,Leardini Alberto,Portinaro Nicola,Panou Artemisia Journal of foot and ankle research BACKGROUND:Plano-valgus is a common alteration of the paediatric foot, characterized by valgus hindfoot, foot pronation and drop of the medial longitudinal arch. Despite their importance in the diagnosis and classification of plano-valgus foot condition, little information is available on functional alterations of the major joints spanning the medial longitudinal arch - i.e. midtarsal and tarso-metatarsal. Aim of the study was to provide objective description of the alterations in plano-valgus midfoot joints with respect to those in an age-matched normally-developed feet population. METHODS:Twenty adolescents (13.3 ± 0.8 years) with bilateral plano-valgus feet underwent clinical examination and were gait-analysed via a validated 4-segment foot model. This allowed to measure static foot posture, kinematics of the main foot joints, and medial longitudinal arch deformation during walking at comfortable speed. Range of motion and temporal profiles of joint rotations were compared to those from a control population of age-matched adolescents with normally-developed feet. RESULTS:The plano-valgus midtarsal joint was more dorsiflexed, everted and abducted than that in the control group, and showed reduced sagittal-plane RoM (plano-valgus = 15.9 degrees; control = 22.2 degrees;  <  0.01). The tarso-metarsal joint was more plantarflexed and adducted, and showed larger frontal-plane RoM. The MLA showed larger RoM and was lower throughout the stance phase of the gait cycle. CONCLUSION:Significant postural and kinematic alterations are present at the midtarsal and tarso-metarsal joints of adolescents with plano-valgus feet. Objective identification and quantification of plano-valgus foot alterations, via non-invasive gait-analysis, is relevant to improving the diagnosis of this condition and to evaluating the effect of conservative treatments and of surgical corrections by different techniques. 10.1186/s13047-018-0297-7
Foot Orthoses for Treating Flat Feet in Children. American family physician
Associated correction of forefoot alignment with hindfoot fusion for pes planovalgus deformity. Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:The present study aimed to investigate changes in hallux alignment after corrective surgery for adult-acquired flatfoot deformity (AAFD). PATIENTS AND METHODS:The present study retrospectively investigated the changes of hallux alignment in 37 feet (33 patients) which were treated with double or triple arthrodesis of the hindfoot for AAFD between 2015 and 2021 and could be followed up to one year postoperatively. RESULTS:Hallux valgus (HV) angle significantly decreased by a mean 4.1° among the whole 37 subjects and by a mean 6.6° among the 24 subjects who had a preoperative HV angle of 15° or more. Those who had HV correction (HV angle correction ≥ 5°) demonstrated more near-normal postoperative alignment of the medial longitudinal arch and hindfoot than those without HV correction. CONCLUSIONS:Hindfoot fusion for AAFD could improve preoperative HV deformity to some degree. HV correction was associated with proper realignment of the midfoot and hindfoot. LEVEL OF EVIDENCE:Level IV; retrospective case series. 10.1016/j.fas.2023.02.012
Outcomes of 2B Adult Acquired Flatfoot Deformity Correction in Patients With and Without Spring Ligament Tear. Foot & ankle international BACKGROUND:It is currently unclear how injury to the spring ligament (SL) affects the preoperative presentation of adult acquired flatfoot deformity (AAFD) or the outcome of operative reconstruction. The purposes of this study were to assess the preoperative features and pre- or postoperative function of patients who underwent direct operative repair of an SL tear compared to those without a tear. METHODS:86 patients undergoing operative correction of grade 2B AAFD by a single fellowship-trained foot and ankle orthopaedic surgeon were reviewed at an average follow-up of 45.9 months. There were 35 feet found to have an SL tear that underwent concomitant debridement and direct repair of the SL. Patient charts were reviewed for demographic information, preoperative visual analog scale (VAS) pain level, and their Foot and Ankle Ability Measure (FAAM) activities of daily living (ADL) and sports subscales. Preoperative radiographic parameters were assessed. Patient outcomes of VAS pain, FAAM-ADL, and FAAM-Sports were collected and compared between groups. RESULTS:Those with an SL tear had significantly lower FAAM-ADL and sports scores, with higher VAS pain scores preoperatively. Patient age, talonavicular uncoverage percentage, and talonavicular angle were found to be associated with spring ligament degeneration. At final follow-up, patients demonstrated a significant improvement in all outcome parameters, with no statistical difference found with patient satisfaction, final postoperative VAS pain, FAAM-ADL, or FAAM-Sports in those requiring a repair of their SL as compared to the control group. CONCLUSION:Increasing patient age, increasing talonavicular uncoverage percentage, and decreasing talonavicular angle are all independently associated with increased likelihood of patients with AAFD having an SL tear. At follow-up for operative treatment of grade 2B AAFD flatfoot with our approach, we found no clinical outcomes difference between those without SL tears and those with SL tears treated with concomitant SL debridement and repair. LEVEL OF EVIDENCE:Level III, retrospective cohort study. 10.1177/10711007211027270
Plantar pressure distribution in the evaluation and differentiation of flatfeet. Gait & posture BACKGROUND:Although foot diseases are common, only a few studies have detailed the biomechanical and anatomical components of each disorder. The most reliable diagnostic tool for flatfoot is X-ray radiography. Achieving a similar accurate and objective diagnosis using another assessment tool, such as plantar pressure measurements, can be more convenient in clinical practice. RESEARCH QUESTION:To identify foot plantar pressure characteristics that primarily detect flatfoot based on X-ray, which addresses the use of such assessments for flatfoot diagnosis. In addition, to compare between the normal foot, flatfoot with positive Foot Posture Index-6 (FPI), and flatfoot with positive FPI and radiographic measures. METHODS:Sixty-two feet were examined from healthy female subjects aged 20.38 ± 1.10 years. According to the results of FPI and X-ray, each sample was assigned to one of the three groups (normal: negative FPI; FPI+: FPI ≥ +6; X-ray and FPI+: Arch Angle ≥ 165°, CP ≤ 12.3° and FPI ≥ +6) and compared using plantar pressure variables. RESULTS:As per normal group compared to X-ray and FPI+ group, there was a significant difference in the surface area (P-value: 0.01, 95 % CI: -26.58 to -3.62), force (P-value: 0.04, 95 % CI: -10.37 to -0.09), and pressure (P-value: 0.01, 95 % CI: -56.78 to -6.35) in the medial foot. Similarly, the arch index among the normal group and the X-ray and FPI+ group showed significant differences (Static AI; P-value: 0.003, 95 % CI: -0.21 to -0.04). CONCLUSION:There was a significant difference in plantar pressure between the normal feet and flatfeet with positive FPI and X-ray in the medial foot area. SIGNIFICANCE:To attain a consensus among diagnostic approaches to identify flatfoot, the combined comparison of observational, foot pressure, and radiographic methods that have shown considerable reliability can be useful for clinical practice. 10.1016/j.gaitpost.2023.01.019
The Effect of Progressive Lateral Column Lengthening in a Novel Stage II-B Flatfoot Cadaveric Model Evaluated Using Software-Guided Radiographic Measurements of Foot Alignment. Foot & ankle international BACKGROUND:This work used software-guided radiographic measurement to assess the effects of progressive lateral column lengthening (LCL) on restoring alignment in a novel cadaveric model of stage II-B flatfoot deformity. METHODS:A stage II-B flatfoot was created in 8 cadaveric specimens by transecting the spring ligament complex, anterior deltoid, and interosseous talocalcaneal and cervical ligaments. Weightbearing computed tomographic (WBCT) scans were performed with specimens under 450 N of compressive load in the intact, flat, and 6-, 8-, and 10-mm lateral column-lengthening conditions. Custom software-guided radiographic measurements of the lateral talo-first metatarsal (Meary) angle, anteroposterior talo-first metatarsal angle, naviculocuneiform overlap, and 2 new measures (plantar fascia [PF] distance and angle) were recorded on digitally reconstructed radiographs. Four anonymized analysts performed measurements twice. Intra- and interobserver agreement was assessed using intraclass correlation coefficients (ICCs). RESULTS:Six-millimeter LCL restored alignment closest to the intact foot in this new cadaveric model, whereas 10-mm lengthening tended toward overcorrection. The PF line displaced laterally in the flatfoot condition, and LCL restored the PF line to a location beneath the talonavicular joint. Interobserver agreement was excellent for PF distance (ICC = 0.99) and naviculocuboid overlap (ICC = 0.91), good for Meary angle (ICC = 0.81) and PF angle (ICC = 0.69), and acceptable for the talonavicular coverage angle (ICC = 0.65). CONCLUSION:In this stage II-B cadaveric flatfoot model, cervical ligament transection was essential to create deformity after the medial hindfoot ligaments were transected. Software-guided radiographic measurement proved reliable; standardized implementation should improve comparability between studies of flatfoot deformity. The novel PF distance performed most consistently (ICC = 0.99) and warrants further study. With this model, we found that a 6-mm LCL restored alignment closest to the intact foot, whereas 10-mm lengthening tended toward overcorrection. CLINICAL RELEVANCE:Future joint-sparing flatfoot corrections may consider using a relatively small LCL combined with other bony and/or anatomic ligament/tendon reconstructions. 10.1177/10711007221091817
Adult-acquired flatfoot deformity and age-related differences in foot and ankle kinematics during the single-limb heel-rise test. Chimenti Ruth L,Tome Joshua,Hillin Cody D,Flemister Adolph S,Houck Jeff The Journal of orthopaedic and sports physical therapy STUDY DESIGN:Cross-sectional laboratory study. OBJECTIVE:To compare single-limb heel-rise performance and foot-ankle kinematics between persons with stage 2 adult-acquired flat foot deformity (AAFD) and healthy controls. BACKGROUND:The inability to perform a single-limb heel rise is considered a positive functional diagnostic test for AAFD. However, which foot motions contribute to poor performance of this task are not known. METHODS:Fifty individuals participated in this study, 20 with stage 2 AAFD (mean ± SD age, 57.6 ± 11.3 years), and 15 older participants (age, 56.8 ± 5.3 years) and 15 younger participants (age, 22.2 ± 2.4 years) without AAFD as control groups. Forefoot (sagittal plane) and rear foot (sagittal and frontal planes) kinematics were collected using a 3-D motion analysis system. Heel-rise performance (heel height) and kinematics (joint angles, excursions) were evaluated. One-way and 2-way analyses of variance were used to examine differences in heel-rise performance and kinematics between groups. RESULTS:Individuals with AAFD and older controls demonstrated lower heel-rise height than those in the younger control group (P<.001). Persons with AAFD demonstrated higher degrees of first metatarsal dorsiflexion (P<.001), lower ankle plantar flexion (P<.001), and higher subtalar eversion (P = .027) than those in the older control group. Persons with AAFD demonstrated lower ankle excursion (P<.001) and first metatarsal excursion (P<.001) than those in the older control group, but no difference in subtalar excursion (P = .771). CONCLUSION:Persons with stage 2 AAFD did not achieve sufficient heel height during a single-leg heel rise. Both forefoot and rear foot kinematics in the sagittal plane, as opposed to the frontal plane, contributed to the lower heel height in participants with stage 2 AAFD. Older controls demonstrated lower heel-rise height than younger controls, indicating that clinical expectations of heel-rise performance may need to be adjusted for age. 10.2519/jospt.2014.4939
Immediate Effects of Medially Posted Insoles on Lower Limb Joint Contact Forces in Adult Acquired Flatfoot: A Pilot Study. Peng Yinghu,Wong Duo Wai-Chi,Wang Yan,Chen Tony Lin-Wei,Tan Qitao,Chen Zhenxian,Jin Zhongmin,Zhang Ming International journal of environmental research and public health Flatfoot is linked to secondary lower limb joint problems, such as patellofemoral pain. This study aimed to investigate the influence of medial posting insoles on the joint mechanics of the lower extremity in adults with flatfoot. Gait analysis was performed on fifteen young adults with flatfoot under two conditions: walking with shoes and foot orthoses (WSFO), and walking with shoes (WS) in random order. The data collected by a vicon system were used to drive the musculoskeletal model to estimate the hip, patellofemoral, ankle, medial and lateral tibiofemoral joint contact forces. The joint contact forces in WSFO and WS conditions were compared. Compared to the WS group, the second peak patellofemoral contact force ( < 0.05) and the peak ankle contact force ( < 0.05) were significantly lower in the WSFO group by 10.2% and 6.8%, respectively. The foot orthosis significantly reduced the peak ankle eversion angle ( < 0.05) and ankle eversion moment ( < 0.05); however, the peak knee adduction moment increased ( < 0.05). The reduction in the patellofemoral joint force and ankle contact force could potentially inhibit flatfoot-induced lower limb joint problems, despite a greater knee adduction moment. 10.3390/ijerph17072226
Extrinsic foot muscle forces and joint contact forces in flexible flatfoot adult with foot orthosis: A parametric study of tibialis posterior muscle weakness. Peng Yinghu,Wang Yan,Wong Duo Wai-Chi,Chen Tony Lin-Wei,Zhang Guoxin,Tan Qitao,Zhang Ming Gait & posture BACKGROUND:The posterior tibialis tendon dysfunction (PTTD) is typically associated with progressive flatfoot deformity, which could be alleviated with foot orthosis. However, the evaluation of tibialis posterior (TP) weakness on lower limb mechanics of flatfoot adults with foot orthoses is scarce and requires further investigation. RESEARCH QUESTION:This study aimed to examine the effects of TP weakness on lower limb mechanics in flatfoot adults with foot orthosis through gait analysis and musculoskeletal modelling. METHODS:Fifteen young adults with flatfoot were recruited from University to perform a gait experiment with and without foot orthoses. Data collected from the motion capture system were used to drive the musculoskeletal modelling for the estimation of the joint force and extrinsic muscle forces of the lower limb. A parametric analysis was conducted by adjusting the TP muscle strength from 40 % to 100 %. Two-way repeated measures ANOVA was used to compare the peak extrinsic foot muscle forces and joint forces among different levels of TP weakness and insole conditions. RESULTS:TP weakness significantly increased ankle joint force superoinferiorly (F = 125.9, p < 0.001) and decreased anteroposteriorly (F = 125.9, p < 0.001), in addition to a significant increase in the muscle forces of flexor hallucis longus (p < 0.001) and flexor digitorum longus (p < 0.001). Besides, the foot orthosis significantly reduced most peak muscle forces whilst significantly reduced the second peak knee force and peak ankle force compared to the control condition (F = 8.79-30.9, p < 0.05). SIGNIFICANCE:The increased extrinsic foot muscle forces (flexor hallucis longus and flexor digitorum longus) and ankle joint forces in the TP weakness condition indicated that TP weakness may induce compensatory muscle activation and attenuated joint load. The abnormal muscle and joint mechanics in flatfoot adults with TP weakness might be restored by the orthosis. 10.1016/j.gaitpost.2021.05.009
Plantar load transfer in children: a descriptive study with two pathological case studies. Brierty Alexis,Carty Christopher P,Giacomozzi Claudia,Phillips Teresa,Walsh Henry P J,Bade David,Horan Sean BMC musculoskeletal disorders BACKGROUND:Typical gait is often considered to be highly symmetrical, with gait asymmetries typically associated with pathological gait. Whilst gait symmetry is often expressed in symmetry ratios, measures of symmetry do not provide insight into how these asymmetries affect gait variables. To fully understand changes caused by gait asymmetry, we must first develop a normative database for comparison. Therefore, the aim of this study was to describe normative reference values of regional plantar load and present comparisons with two pathological case studies. METHODS:A descriptive study of the load transfer of plantar pressures in typically developed children was conducted to develop a baseline for comparison of the effects of gait asymmetry in paediatric clinical populations. Plantar load and 3D kinematic data was collected for 17 typically developed participants with a mean age of 9.4 ± 4.0 years. Two case studies were also included; a 10-year-old male with clubfoot and an 8-year-old female with a flatfoot deformity. Data was analysed using a kinematics-pressure integration technique for anatomical masking into 5 regions of interest; medial and lateral forefoot, midfoot, and medial and lateral hindfoot. RESULTS:Clear differences between the two case studies and the typical dataset were seen for the load transfer phase of gait. For case study one, lateral bias was seen in the forefoot of the trailing foot across all variables, as well as increases in contact area, force and mean pressure in the lateral hindfoot of the leading foot. For case study two, the forefoot of the trailing foot produced results very similar to the typical dataset across all variables. In the hindfoot of the leading foot, medial bias presents most notably in the force and mean pressure graphs. CONCLUSIONS:This study highlights the clinical significance of the load transfer phase of gait, providing meaningful information for intervention planning. 10.1186/s12891-021-04364-9
Peritalar Kinematics With Combined Deltoid-Spring Ligament Reconstruction in Simulated Advanced Adult Acquired Flatfoot Deformity. Foot & ankle international BACKGROUND:Adult acquired flatfoot deformity (AAFD) is a complex and progressive deformity involving the ligamentous structures of the medial peritalar joints. Recent anatomic studies demonstrated that the spring and deltoid ligaments form a greater medial ligament complex, the tibiocalcaneonavicular ligament (TCNL), which provides medial stability to the talonavicular, subtalar, and tibiotalar joints. The aim of this study was to assess the biomechanical effect of a spring ligament tear on the peritalar stability. The secondary aim was to assess the effect of TCNL reconstruction in restoration of peritalar stability in comparison with other medial stabilization procedures, anatomic spring or deltoid ligament reconstructions, in a cadaveric flatfoot model. METHODS:Ten fresh-frozen cadaveric foot specimens were used. Reflective markers were mounted on the tibia, talus, navicular, calcaneus, and first metatarsal. Peritalar joint kinematics were captured by a multiple-camera motion capture system. Mild, moderate, and severe flatfoot models were created by sequential sectioning of medial capsuloligament complex followed by cyclic axial loading. Spring only, deltoid only, and combined deltoid-spring ligament (TCNL) reconstructions were performed. The relative kinematic changes were compared using 2-way analysis of variance (ANOVA). RESULTS:Compared with the initial condition, we noted significantly increased valgus alignment of the subtalar joint of 5.1 ± 2.3 degrees ( = .031) and 5.8 ± 2.7 degrees ( < .01) with increased size of the spring ligament tear to create moderate to severe flatfoot, respectively. We noted an increased tibiotalar valgus angle of 5.1 ± 2.0 degrees ( = .03) in the severe model. Although all medial ligament reconstruction methods were able to correct forefoot abduction, the TCNL reconstruction was able to correct both the subtalar and tibiotalar valgus deformity ( = .04 and = .02, respectively). CONCLUSION:The TCNL complex provided stability to the talonavicular, subtalar, and tibiotalar joints. The combined deltoid-spring ligament (TCNL) reconstructions restored peritalar kinematics better than isolated spring or deltoid ligament reconstruction in the severe AAFD model. CLINICAL RELEVANCE:The combined deltoid-spring ligament (TCNL) reconstruction maybe considered in advanced AAFD with medial peritalar instability: stage IIB with a large spring ligament tear or stage IV. 10.1177/1071100720929004
Flatfoot deformity affected the kinematics of the foot and ankle in proportion to the severity of deformity. Shin Hyuck Soo,Lee Jae Hee,Kim Eo Jin,Kyung Min Gyu,Yoo Hyo Jeong,Lee Dong Yeon Gait & posture BACKGROUND:Flatfoot deformity is thought to affect gait kinematics, but the effect of flatfoot on segmental motion of the foot during gait remains unclear. Recently, multi-segmental foot models (MFMs) have been introduced for the in vivo analysis of dynamic foot kinematics. The objective of this study was to find the effect of flatfoot on segmental motion of the foot during gait in females by comparisons with age and gender controlled healthy adults. METHODS:Thirty six symptomatic flatfeet patients (52-80 years old) and 42 symptom-free female participants without flatfoot (60-69 years old) were included in this study. According to the Meary angle (MA) on standing lateral radiograph, flatfoot patients are divided into severe (SFF, MA>20°) and moderate (MFF, 10°<MA<20°) flatfoot group. Segmental foot kinematics were evaluated using a 3D MFM of a 15-marker set (DuPont Foot Model). RESULTS:The cadence, speed, stride length, and step width are significantly lower in flatfoot patients. ROM of sagittal and transverse plane of the hindfoot, transverse plane of the forefoot and sagittal plane of the hallux were lower in severe flatfoot group. In the SFF group, there was loss of hindfoot adduction motion during the terminal stance and pre-swing phase. In forefoot kinematics, the SFF group showed significantly supinated and abducted position throughout the gait cycle. In hindfoot kinematics, plantar flexion motion in the pre-swing phase was significantly lower in flatfoot patients in proportion to the severity of the deformity. CONCLUSIONS:We showed that flatfoot deformity affected the kinematics of the foot and ankle in proportion to the severity of deformity. We cautiously suggest that there might be a threshold of flatfoot precluding normal foot kinematics because normal kinematic pattern of the foot might not collapse in moderate flatfoot with a Meary angle of less than 20 degrees. 10.1016/j.gaitpost.2019.06.002
Nonanatomic versus anatomic techniques in spring ligament reconstruction: biomechanical assessment via a finite element model. Xu Can,Li Ming Qing,Wang Chenggong,Liu Hua Journal of orthopaedic surgery and research BACKGROUND:Several approaches to spring ligament reconstruction have been reported. However, a comparative study of nonanatomic and anatomic techniques with respect to biomechanical responses, such as kinematics and contact characteristics, has not been previously performed via a finite element analysis. The purpose of this study was to evaluate the biomechanical results of such spring ligament reconstructions via a finite element analysis. METHODS:A three-dimensional finite element model of the foot was developed and validated, and four reconstruction methods were simulated. The talonavicular dorsiflexion and abduction, hindfoot valgus, and contact characteristics in the Chopart joints were quantified in each model. RESULTS:Nonanatomic reconstructions corrected the talonavicular and hindfoot deformities to a greater extent than the anatomic reconstructions. The anatomic techniques also corrected the abduction and dorsiflexion deformities, although they presented insufficient power to correct for hindfoot valgus. None of the procedures restored the contact characteristics of the talonavicular and calcaneocuboid joints to those of a normal condition. CONCLUSION:Nonanatomic reconstruction of the spring ligament complex provided the greatest correction for midfoot and hindfoot misalignments in flatfoot. Severe deformities with large amounts of midfoot pronation and hindfoot valgus may be better treated with nonanatomic reconstruction methods. The spring ligament reconstruction method may mitigate the need for nonanatomic bony procedures associated with complications and allows for the preservation of the triple joint complex. 10.1186/s13018-019-1154-5
Analysis of the main soft tissue stress associated with flexible flatfoot deformity: a finite element study. Zhang Yi-Jun,Guo Yan,Long Xiao,Du Jing-Yu,Liu Tao,Lin Xiang-Jin Biomechanics and modeling in mechanobiology A better understanding of soft tissue stress and its role in supporting the medial longitudinal arch in flexible flatfoot could help to guide the clinical treatment. In this study, a 3-Dimensional finite element (FE) foot model was reconstructed to measure the stress of the soft tissue, and its variation in different scenarios related to flexible flatfoot. All bones, cartilages, ligaments and related tendons around the ankle, and fat pad were included in the finite element model. The equivalent stress on the articular surface of the joints in the medial longitudinal arch and the maximum principal stress of the ligaments around the ankle were obtained. The results show that the plantar fascia (PF) is the main tissue in maintaining the medial longitudinal arch. The equivalent stress of all the joints in the medial longitudinal arch increases when the PF attenuation and the talonavicular joint increases, while other joints decreases when all the three tissue attenuation. Moreover, the maximum principal stress variation of calcaneofibular ligament is largest when the PF attenuation and the tibionavicular ligament and posterior tibiotalar ligament are largest when the posterior tibial tendon (PTT) attenuation. The maximum principal stress variation of tibionavicular ligament and posterior tibiotalar ligament are even larger when all the three tissue attenuation. These findings support that the PF is the main factor in maintaining the medial longitudinal arch. The medial longitudinal arch collapse mainly affects the talonavicular joint and the calcaneofibular ligament, the tibionavicular ligament and the posterior tibiotalar ligament. This approach could help to improve the understanding of adult-acquired flatfoot deformity (AAFD). 10.1007/s10237-021-01500-1
Effect of Lateral Column Lengthening on Subtalar Motion in a Cadaveric Model. Harris Mitchell C,Hedrick Brittany N,Zide Jacob R,Thomas Danielle M,Shivers Claire,Siebert Matthew J,Pierce William A,Kanaan Yassine,Riccio Anthony I Foot & ankle international BACKGROUND:Although lengthening of the lateral column through a calcaneal neck osteotomy is an integral component of flatfoot reconstruction in younger patients with flexible planovalgus deformities, concern exists as to the effect of this intra-articular osteotomy on subtalar motion. The purpose of this study was to quantify the alterations in subtalar motion following lateral column lengthening (LCL). METHODS:The subtalar motion of 14 fresh-frozen cadaveric feet was assessed using a 3-dimensional motion capture system and materials testing system (MTS). Following potting of the tibia and calcaneus, optic markers were placed into the tibia, calcaneus, and talus. The MTS was used to apply a rotational force across the subtalar joint to a torque of 5 Nm. Abduction/adduction, supination/pronation, and plantarflexion/dorsiflexion about the talus were recorded. Specimens then underwent LCL via a calcaneal neck osteotomy, which was maintained with a 12-mm porous titanium wedge. Repeat subtalar motion analysis was performed and compared to pre-LCL motion using a paired test. RESULTS:No statistically significant differences in subtalar abduction/adduction (10.9 vs 11.8 degrees, = .48), supination/pronation (3.5 vs 2.7 degrees, = .31), or plantarflexion/dorsiflexion (1.6 vs 1.0 degrees, = .10) were identified following LCL. CONCLUSION:No significant changes in subtalar motion were observed following lateral column lengthening in this biomechanical cadaveric study. CLINICAL RELEVANCE:Although these findings do not obviate concerns of clinical subtalar stiffness following lateral column lengthening for planovalgus deformity correction, they suggest that diminished postoperative subtalar motion, when it occurs, may be due to soft tissue scarring rather than alterations of joint anatomy. 10.1177/1071100720970189
Characterizing multisegment foot kinematics during gait in diabetic foot patients. Journal of neuroengineering and rehabilitation BACKGROUND:The prevalence of diabetes mellitus has reached epidemic proportions, this condition may result in multiple and chronic invalidating long term complications. Among these, the diabetic foot, is determined by the simultaneous presence of both peripheral neuropathy and vasculopathy that alter the biomechanics of the foot with the formation of callosity and ulcerations. To diagnose and treat the diabetic foot is crucial to understand the foot complex kinematics. Most of gait analysis protocols represent the entire foot as a rigid body connected to the shank. Nevertheless the existing multisegment models cannot completely decipher the impairments associated with the diabetic foot. METHODS:A four segment foot and ankle model for assessing the kinematics of the diabetic foot was developed. Ten normal subjects and 10 diabetics gait patterns were collected and major sources of variability were tested. Repeatability analysis was performed both on a normal and on a diabetic subject. Direct skin marker placement was chosen in correspondence of 13 anatomical landmarks and an optoelectronic system was used to collect the data. RESULTS:Joint rotation normative bands (mean plus/minus one standard deviation) were generated using the data of the control group. Three representative strides per subject were selected. The repeatability analysis on normal and pathological subjects results have been compared with literature and found comparable. Normal and pathological gait have been compared and showed major statistically significant differences in the forefoot and midfoot dorsi-plantarflexion. CONCLUSION:Even though various biomechanical models have been developed so far to study the properties and behaviour of the foot, the present study focuses on developing a methodology for the functional assessment of the foot-ankle complex and for the definition of a functional model of the diabetic neuropathic foot. It is, of course, important to evaluate the major sources of variation (true variation in the subject's gait and artefacts from the measurement procedure). The repeatability of the protocol was therefore examined, and results showed the suitability of this method both on normal and pathological subjects. Comparison between normal and pathological kinematics analysis confirmed the validity of a similar approach in order to assess neuropathics biomechanics impairment. 10.1186/1743-0003-6-37
One- and multi-segment foot models lead to opposite results on ankle joint kinematics during gait: Implications for clinical assessment. Pothrat Claude,Authier Guillaume,Viehweger Elke,Berton Eric,Rao Guillaume Clinical biomechanics (Bristol, Avon) BACKGROUND:Biomechanical models representing the foot as a single rigid segment are commonly used in clinical or sport evaluations. However, neglecting internal foot movements could lead to significant inaccuracies on ankle joint kinematics. The present study proposed an assessment of 3D ankle kinematic outputs using two distinct biomechanical models and their application in the clinical flat foot case. METHODS:Results of the Plug in Gait (one segment foot model) and the Oxford Foot Model (multisegment foot model) were compared for normal children (9 participants) and flat feet children (9 participants). Repeated measures of Analysis of Variance have been performed to assess the Foot model and Group effects on ankle joint kinematics. FINDINGS:Significant differences were observed between the two models for each group all along the gait cycle. In particular for the flat feet group, opposite results between the Oxford Foot Model and the Plug in Gait were revealed at heelstrike, with the Plug in Gait showing a 4.7° ankle dorsal flexion and 2.7° varus where the Oxford Foot Model showed a 4.8° ankle plantar flexion and 1.6° valgus. INTERPRETATION:Ankle joint kinematics of the flat feet group was more affected by foot modeling than normal group. Foot modeling appeared to have a strong influence on resulting ankle kinematics. Moreover, our findings showed that this influence could vary depending on the population. Studies involving ankle joint kinematic assessment should take foot modeling with caution. 10.1016/j.clinbiomech.2015.03.004
Morphology and Mechanical Properties of Plantar Fascia in Flexible Flatfoot: A Noninvasive Study. Qian Zhihui,Jiang Zhende,Wu Jianan,Chang Fei,Liu Jing,Ren Lei,Ren Luquan Frontiers in bioengineering and biotechnology Plantar fascia plays an important role in human foot biomechanics; however, the morphology and mechanical properties of plantar fascia in patients with flexible flatfoot are unknown. In this study, 15 flexible flatfeet were studied, each plantar fascia was divided into 12 positions, and the morphologies and mechanical properties in the 12 positions were measured with B-mode ultrasound and shear wave elastography (SWE). Peak pressures under the first to fifth metatarsal heads (MH) were measured with FreeStep. Statistical analysis included 95% confidence interval, intragroup correlation coefficient (ICC), one-way analysis of variance (one-way ANOVA), and least significant difference. The results showed that thickness and Young's modulus of plantar fascia were the largest at the proximal fascia (PF) and decreased gradually from the proximal end to the distal end. Among the five distal branches (DB) of the fascia, the thickness and Young's modulus of the second and third DB were larger. The peak pressures were also higher under the second and third MH. This study found a gradient distribution in that the thickness and Young's modulus gradient decreased from the proximal end to the distal end of plantar fascia in the longitudinal arch of flexible flatfeet. In the transverse arch, the thickness and Young's modulus under the second and third DB were larger than those under the other three DB in flexible flatfoot, and the peak pressures under the second and third MH were also larger than those under the other three MH in patients with flexible flatfoot. These findings deepen our understanding of the changes of biomechanical properties and may be meaningful for the study of pathological mechanisms and therapy for flexible flatfoot. 10.3389/fbioe.2021.727940
Finite element analysis of subtalar joint arthroereisis on adult-acquired flexible flatfoot deformity using customised sinus tarsi implant. Journal of orthopaedic translation BACKGROUND:Subtalar arthroereisis may cause sinus tarsi pain complications. In this study, we aimed to introduce a customised implant that facilitated treatment effect and less impingement. The biomechanical outcome between the intact and implant conditions was compared using finite element analysis. METHODS:A female patient with flatfoot (age: 36 years, height: 156 ​cm, body mass: 51 ​kg) was recruited as the model patient. The customised implant was designed from the extracted geometry. Boundary and loading conditions were assumed from the data of a normal participant. Four gait instants, including the ground reaction force first peak (25% stance), valley (45%), initial push-off (60%) and second peak (75%) were analyzed. RESULTS:The navicular height was elevated by 4.2% at 25% stance, whereas the strain of the spring, plantar cuneonavicular and plantar cuboideonavicular ligaments were reduced. The talonavicular joint force decreased and the calcaneocuboid joint increased by half and 67%, respectively, representing a lateralised load pathway. There was a stress concentration at the sulcus tali reaching 15.29 ​MPa. CONCLUSION:Subtalar arthroereisis using a customised implant may produce some positive treatment effects in terms of navicular height elevation, ligament strain relief and lateralised joint loading pathway. Although the concentrated stress at the sulcus tali did not exceed the threshold of bone breakdown, we could not rule out the potential of vascular disturbance owing to the remarkable elevation of stress. Future study may enlarge the contact area of the bone-implant interface by considering customisation based on the dynamic change of the sinus tarsi during walking gait. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE:Geometry mismatch of prefabricated implants could be the reason for complications. With the advancement of 3D printing, customising implant becomes possible and may improve treatment outcome. This study implemented a theoretical model approach to explore its potential under a simulation of walking. 10.1016/j.jot.2020.02.004
Effects of idiopathic flatfoot deformity on knee adduction moments during walking. Byrnes S Kimberly,Wearing Scott,Böhm Harald,Dussa Chakravarthy U,Horstmann Thomas Gait & posture INTRODUCTION:Flatfoot deformity is commonly characterized by a subtalar valgus, a low medial longitudinal arch, and abduction of the forefoot. Although flatfoot deformity has been associated with lower first (KAM1) and second (KAM2) peak knee adduction moments during walking, the biomechanical connection remains unknown. RESEARCH QUESTION:We hypothesized that hindfoot eversion, lateral calcaneal shift correlate with KAM1 and forefoot abduction and arch height with KAM2, due to the lateralization of the ground reaction force vector resulting from shifted heel and forefoot in flatfoot deformity. METHODS:Gait data from 103 children with flatfoot deformity who underwent three-dimensional gait analysis with the Oxford Foot Model were retrospectively included. Children with knee varus/valgus, in- and out-toeing were excluded. Fifteen healthy children with a rectus foot type were also collected from the database. Lateral calcaneal shift was defined as the distance between the projection of the ankle joint center onto the calcaneal axis and the midpoint of the calcaneal axis formed by the medial and lateral calcaneal markers. A subgroup of children with idiopathic flatfoot deformity that had received corrective surgery was also identified. Statistical analysis included Pearson's correlations and independent and paired t-tests (α < .05). RESULTS:When compared to a norm cohort, flatfooted children had significant lower KAM1 and KAM2 (t-test, P < .001). Lateral calcaneal shift correlated with KAM1 and KAM2 (r = 0.42, p < .001 and r = 0.32, P < .001, respectively). Arch height correlated with KAM2 (r = 0.23, p = 0.017). KAM1 and KAM2 normalized after surgery and the change in KAM1 correlated with the change in lateral calcaneal shift for children who underwent corrective surgery. SIGNIFICANCE:Lateral calcaneal shift explains the reduction of KAM1 by lateralization of the point of force application in flatfooted children. It is recommended to consider the lateral calcaneal shift when investigating KAM in gait analysis research. 10.1016/j.gaitpost.2020.12.021
Analysis of the main passive soft tissues associated with adult acquired flatfoot deformity development: A computational modeling approach. Cifuentes-De la Portilla Christian,Larrainzar-Garijo Ricardo,Bayod Javier Journal of biomechanics Adult acquired flatfoot deformity (AAFD) is a pathology with a wide range of treatment options. Physicians decide the best treatment based on their experience, so the process is entirely subjective. A better understanding of soft tissue stress and its contribution in supporting the plantar arch could help to guide the clinical decision. Traditional experimental trials cannot consistently evaluate the contribution of each tissue. Therefore, in this research a 3-Dimensional FE foot model was reconstructed from a normal patient in order to measure the stress of the passive stabilizers of the arch, and its variation in different scenarios related with intermediate stages of AAFD development. All bones, the plantar fascia (PF), cartilages, plantar ligaments and the spring ligament (SL) were included, respecting their anatomical distribution and biomechanical characteristics. An AAFD evaluation scenario was simulated. The relative contribution of each tissue was obtained comparing each result with a normal case. The results show that PF is the main tissue that prevents the arch elongation, while SL mainly reduces the foot pronation. Long and short plantar ligaments play a secondary role in this process. The stress increment on both PF and SL when one of two fails suggests that these tissues complement each other. These findings support the theory that regards the tibialis posterior tendon as a secondary actor in the arch maintenance, compared with the PF and the SL, because this tendon is overstretched by the hindfoot pronation around the talonavicular joint. This approach could help to improve the understanding of AAFD. 10.1016/j.jbiomech.2018.12.047
Effect of foot shape on the three-dimensional position of foot bones. Ledoux William R,Rohr Eric S,Ching Randal P,Sangeorzan Bruce J Journal of orthopaedic research : official publication of the Orthopaedic Research Society To eliminate some of the ambiguity in describing foot shape, we developed three-dimensional (3D), objective measures of foot type based on computerized tomography (CT) scans. Feet were classified via clinical examination as pes cavus (high arch), neutrally aligned (normal arch), asymptomatic pes planus (flat arch with no pain), or symptomatic pes planus (flat arch with pain). We enrolled 10 subjects of each foot type; if both feet were of the same foot type, then each foot was scanned (n=65 total). Partial weightbearing (20% body weight) CT scans were performed. We generated embedded coordinate systems for each foot bone by assuming uniform density and calculating the inertial matrix. Cardan angles were used to describe five bone-to-bone relationships, resulting in 15 angular measurements. Significant differences were found among foot types for 12 of the angles. The angles were also used to develop a classification tree analysis, which determined the correct foot type for 64 of the 65 feet. Our measure provides insight into how foot bone architecture differs between foot types. The classification tree analysis demonstrated that objective measures can be used to discriminate between feet with high, normal, and low arches. 10.1002/jor.20262
A comparison of foot kinematics in people with normal- and flat-arched feet using the Oxford Foot Model. Levinger Pazit,Murley George S,Barton Christian J,Cotchett Matthew P,McSweeney Simone R,Menz Hylton B Gait & posture Foot posture is thought to influence predisposition to overuse injuries of the lower limb. Although the mechanisms underlying this proposed relationship are unclear, it is thought that altered foot kinematics may play a role. Therefore, this study was designed to investigate differences in foot motion between people with normal- and flat-arched feet using the Oxford Foot Model (OFM). Foot posture in 19 participants was documented as normal-arched (n=10) or flat-arched (n=9) using a foot screening protocol incorporating measurements from weightbearing antero-posterior and lateral foot radiographs. Differences between the groups in triplanar motion of the tibia, rearfoot and forefoot during walking were evaluated using a three-dimensional motion analysis system incorporating a multi-segment foot model (OFM). Participants with flat-arched feet demonstrated greater peak forefoot plantar-flexion (-13.7° ± 5.6° vs -6.5° ± 3.7°; p=0.004), forefoot abduction (-12.9° ± 6.9° vs -1.8° ± 6.3°; p=0.002), and rearfoot internal rotation (10.6° ± 7.5° vs -0.2°± 9.9°; p=0.018) compared to those with normal-arched feet. Additionally, participants with flat-arched feet demonstrated decreased peak forefoot adduction (-7.0° ± 9.2° vs 5.6° ± 7.3°; p=0.004) and a trend towards increased rearfoot eversion (-5.8° ± 4.4° vs -2.5° ± 2.6°; p=0.06). These findings support the notion that flat-arched feet have altered motion associated with greater pronation during gait; factors that may increase the risk of overuse injury. 10.1016/j.gaitpost.2010.07.013
Differences of ground reaction forces and kinematics of lower extremity according to landing height between flat and normal feet. Chang Jong Sung,Kwon Yong Hyun,Kim Chung Sun,Ahn Sang-Ho,Park So Hyun Journal of back and musculoskeletal rehabilitation The study compared lower extremity kinematics and kinetics between male subjects with flat and normal feet when landing on both feet from platforms at different heights. Ten subjects with a flat feet arch and 10 subjects with a normal foot arch were recruited. They performed a double limb drop landing from 20, 40, and 60 cm onto a force-plate. A three-dimensional motion analysis system, force plates, and electromyography were used to analyze lower extremity kinetic and kinematic data. The GRF and angle of sagittal plane significantly increased with landing height in the flat foot group. In particular, hip joint angles at a height of 60 cm were significantly greater. The electromyography values were significantly higher for the tibialis anterior and vastus lateralis muscles, but were significantly lower in the abductor hallucis, gastrocnemius, and biceps femoris muscles in the flat foot group. GRF, joint angles, and muscle activity patterns in the lower extremities increases more with height in flat footed individuals than in people with a normal foot arch. Flat feet may aggravate the risk of shock on landing from a height; this might be ameliorated by a compensatory strategy at the hip joints to facilitate load distribution. 10.3233/BMR-2012-0306
Biomechanical Cadaveric Evaluation of the Role of Medial Column Instability in Hallux Valgus Deformity. Foot & ankle international BACKGROUND:Medial column instability is a frequent finding in patients with flatfeet and hallux valgus, within others. The etiology of hallux valgus is multifactorial, and medial ray axial rotation has been mentioned as having an individual role. Our objective was to design a novel cadaveric foot model where we could re-create through progressive medial column ligament damage some components of a hallux valgus deformity. METHODS:Ten fresh-frozen lower leg specimens were used, and fluorescent markers were attached in a multisegment foot model. Constant axial load and cyclic tibial rotation (to simulate foot pronation) were applied, including pull on the flexor hallucis longus tendon (FHL). We first damaged the intercuneiform (C1-C2) ligaments, second the naviculocuneiform (NC) ligaments, and third the first tarsometatarsal ligaments, leaving the plantar ligaments unharmed. Bony axial and coronal alignment was measured after each ligament damage. Statistical analysis was performed. RESULTS:A significant increase in pronation of multiple segments was observed after sectioning the NC ligaments. Damaging the tarsometatarsal ligament generated small supination and varus changes mainly in the medial ray. No significant change was observed in axial or frontal plane alignment after damaging the C1-C2 ligaments. The FHL pull exerted a small valgus change in segments of the first ray. DISCUSSION:In this biomechanical cadaveric model, the naviculocuneiform joint was the most important one responsible for pronation of the medial column. Bone pronation occurs along the whole medial column, not isolated to a certain joint. Flexor hallucis longus pull appears to play some role in frontal plane alignment, but not in bone rotation. This model will be of great help to further study medial column instability as one of the factors influencing medial column pronation and its relevance in pathologies like hallux valgus. CLINICAL RELEVANCE:This cadaveric model suggests a possible influence of medial column instability in first metatarsal pronation. With a thorough understanding of a condition's origin, better treatment strategies can be developed. 10.1177/10711007221081461
Evaluation of assumptions in foot and ankle biomechanical models. Clinical biomechanics (Bristol, Avon) BACKGROUND:A variety of biomechanical models have been used in studies of foot and ankle disorders. Assumptions about the element types, material properties, and loading and boundary conditions are inherent in every model. It was hypothesized that the choice of these modeling assumptions could have a significant impact on the findings of the model. METHODS:We investigated the assumptions made in a number of biomechanical models of the foot and ankle and evaluated their effects on the results of the studies. Specifically, we focused on: (1) element choice for simulation of ligaments and tendons, (2) material properties of ligaments, cortical and trabecular bones, and encapsulating soft tissue, (3) loading and boundary conditions of the tibia, fibula, tendons, and ground support. FINDINGS:Our principal findings are: (1) the use of isotropic solid elements to model ligaments and tendons is not appropriate because it allows them to transmit unrealistic bending and twisting moments and compressive forces; (2) ignoring the difference in elastic modulus between cortical and trabecular bones creates non-physiological stress distribution in the bones; (3) over-constraining tibial motion prevents anticipated deformity within the foot when simulating foot deformities, such as progressive collapsing foot deformity; (4) neglecting the Achilles tendon force affects almost all kinetic and kinematic parameters through the foot; (5) the axial force applied to the tibia and fibula is not equal to the ground reaction force due to the presence of tendon forces. INTERPRETATION:The predicted outcomes of a foot model are highly sensitive to the model assumptions. 10.1016/j.clinbiomech.2022.105807
A biomechanical analysis of posterior tibial tendon dysfunction, medial displacement calcaneal osteotomy and flexor digitorum longus transfer in adult acquired flat foot. Arangio George A,Salathe Eric P Clinical biomechanics (Bristol, Avon) BACKGROUND:Biomechanical models have been used to study stress in the metatarsals, subtalar motion, lateral column lengthening and subtalar arthroereisis. Posterior tibial tendon dysfunction has been associated with increased loads in the arch of the acquired flat foot. We examine whether a 10 millimeter (mm) medial displacement calcaneal osteotomy and flexor digitorum longus transfer to the navicular reduces these increased loads in the flat foot. METHODS:The response of a normal foot, a foot with posterior tibial tendon dysfunction, and a flat foot to an applied load of 683Newton was analyzed using a multi-segment biomechanical model. The distribution of load on the metatarsals, the moment about each joint, the force on each of the plantar ligaments and the muscle forces were computed. FINDINGS:Posterior tibial tendon dysfunction results in increased load on the medial arch, which may cause the foot to flatten. A 10mm medial displacement calcaneal osteotomy substantially decreases the load on the first metatarsal and the moment at the talo-navicular joint and increases the load on the fifth metatarsal and the calcaneal-cuboid joint. Adding the flexor digitorum longus transfer to the medial displacement calcaneal osteotomy has only a small effect on the flattened foot. INTERPRETATION:Our biomechanical analysis illustrates that when the foot becomes flat, the force on the talo-navicular joint increases substantially from its value for the normal foot, and that medial displacement calcaneal osteotomy can reduce this increased force back toward the value occurring in the normal foot. This study provides a biomechanical rationale for medial displacement calcaneal osteotomy treatments for posterior tibial tendon dysfunction. 10.1016/j.clinbiomech.2009.01.009
Biomechanical analysis of the calcaneocuboid joint pressure after sequential lengthening of the lateral column. Xia Jiang,Zhang Peng,Yang Yun-Feng,Zhou Jia-Qian,Li Qian-Ming,Yu Guang-Rong Foot & ankle international BACKGROUND:Lengthening of the lateral column by means of the Evans osteotomy is commonly used for reconstruction of adult and pediatric flatfoot. However, some reports have shown that the Evans osteotomy is linked with increased calcaneocuboid joint pressures and an increased risk of arthritis in the joint. The purpose of this study was to measure the pressure across the calcaneocuboid joint and demonstrate the changing trends of the pressure within the calcaneocuboid joint after sequential lengthening of the lateral column. METHODS:Six cadaver specimens were physiologically loaded and the peak pressure of the calcaneocuboid joint was measured under the following conditions: (1) normal foot, (2) flatfoot, and (3) sequential lengthening of the lateral column by means of the Evans procedure (from 4 mm to 12 mm, in 2 mm increments). RESULTS:Peak pressures across the joint increased significantly from baseline in the flatfoot (P < .05). In the corrected foot, with the increment of the graft, the peak pressure decreased initially and then increased. The pressure reached its minimum value (11.04 ± 1.15 kg/cm(2)) with 8 mm lengthening of the lateral column. The differences were significant compared to the flatfoot (P < .05) and corrected foot with the other sizes of grafts (P < .05), but differences were not significant compared to the intact foot (P = .143). CONCLUSIONS:Lateral column lengthening within a certain extent will decrease the pressure in calcaneocuboid joint with a flatfoot deformity. CLINICAL RELEVANCE:Performing the procedure with an 8 mm lengthening may reduce the risk of the secondary calcaneocuboid osteoarthritis. 10.1177/1071100712464211
Biomechanical stress analysis of the main soft tissues associated with the development of adult acquired flatfoot deformity. Cifuentes-De la Portilla Christian,Larrainzar-Garijo Ricardo,Bayod Javier Clinical biomechanics (Bristol, Avon) BACKGROUND:Adult acquired flatfoot deformity (AAFD) is traditionally related to a tibialis posterior tendon deficiency. In the intermediate stages, treatments are commonly focused on reinforcing this tissue, but sometimes the deformation appears again over time, necessitating the use of more aggressive options. Tissue stress cannot be consistently evaluated through traditional experimental trials. Computational foot modeling extends knowledge of the disease and could help guide the clinical decisions. This study analyzes the biomechanical stress of the main tissues related to AAFD and their capacity to support the plantar arch. METHODS:A FE foot model was reconstructed. All the bones, cartilages and tissues related to AAFD were included, respecting their biomechanical characteristics. The biomechanical tissue stress was quantified. The capacity of each soft tissue to support the plantar arch was measured, following clinical criteria. FINDINGS:Biomechanical stress of the tibialis posterior tendon is considerably superior to both the plantar fascia and spring ligament stress. However, it cannot maintain the plantar arch by itself. Both the tibialis posterior tendon and spring ligament act in reducing the hindfoot pronation, while the plantar fascia is the main tissue that prevents arch elongation. The Achilles tendon action increases the plantar tissue stress. INTERPRETATION:The tibialis posterior tendon stress increases when the spring ligament or the fascia plantar fails. These findings are consistent with the theory that regards the tibialis posterior tendon as a secondary actor because it cannot support the plantar arch and claudicates when the hindfoot has rotated around the talonavicular joint. 10.1016/j.clinbiomech.2018.12.009
Segmental kinematic analysis of planovalgus feet during walking in children with cerebral palsy. Kruger Karen M,Konop Katherine A,Krzak Joseph J,Graf Adam,Altiok Haluk,Smith Peter A,Harris Gerald F Gait & posture Pes planovalgus (flatfoot) is a common deformity among children with cerebral palsy. The Milwaukee Foot Model (MFM), a multi-segmental kinematic foot model, which uses radiography to align the underlying bony anatomy with reflective surface markers, was used to evaluate 20 pediatric participants (30feet) with planovalgus secondary to cerebral palsy prior to surgery. Three-dimensional kinematics of the tibia, hindfoot, forefoot, and hallux segments are reported and compared to an age-matched control set of typically-developing children. Most results were consistent with known characteristics of the deformity and showed decreased plantar flexion of the forefoot relative to hindfoot, increased forefoot abduction, and decreased ranges of motion during push-off in the planovalgus group. Interestingly, while forefoot characteristics were uniformly distributed in a common direction in the transverse plane, there was marked variability of forefoot and hindfoot coronal plane and hindfoot transverse plane positioning. The key finding of these data was the radiographic indexing of the MFM was able to show flat feet in cerebral palsy do not always demonstrate more hindfoot eversion than the typically-developing hindfoot. The coronal plane kinematics of the hindfoot show cases planovalgus feet with the hindfoot in inversion, eversion, and neutral. Along with other metrics, the MFM can be a valuable tool for monitoring kinematic deformity, facilitating clinical decision making, and providing a quantitative analysis of surgical effects on the planovalgus foot. 10.1016/j.gaitpost.2017.03.020
Analysis of biomechanical stresses caused by hindfoot joint arthrodesis in the treatment of adult acquired flatfoot deformity: A finite element study. Cifuentes-De la Portilla Christian,Larrainzar-Garijo Ricardo,Bayod Javier Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Treatments of adult acquired flatfoot deformity in early stages (I-IIa-IIb) are focused on strengthening tendons, in isolation or combined with osteotomies, but in stage III, rigidity of foot deformity requires more restrictive procedures such as hindfoot joint arthrodesis. Few experimental studies have assessed the biomechanical effects of these treatments, because of the difficulty of measuring these parameters in cadavers. Our objective was to quantify the biomechanical stress caused by both isolated hindfoot arthrodesis and triple arthrodesis on the main tissues that support the plantar arch. METHODS:An innovative finite element model was used to evaluate some flatfoot scenarios treated with isolated hindfoot arthrodesis and triple arthrodesis. RESULTS AND CONCLUSIONS:When arthrodeses are done in situ, talonavicular seems a good option, possible superior to subtalar and at least equivalent to triple. Calcaneocuboid arthrodesis reduces significantly both fascia plantar and spring ligament stresses but concentrates higher stresses around the fused joint. 10.1016/j.fas.2019.05.010
Does the way of weight-bearing matter? Single-leg and both-leg standing radiographic and pedobarographic differences in pediatric flatfoot. Gait & posture BACKGROUND:An exact definition is lacking for the term "weight-bearing" or different standing modalities when implementing foot radiographs for children and adults; moreover, only few studies have investigated the relationship between radiographic and pedobarographic measurements. RESEARCH QUESTION:We hypothesized that the method of weight-bearing in single-leg and both-leg standing positions could influence the measurement results in radiographs and the distribution of foot pressure. METHODS:This prospective study evaluated 33 children (66 feet) with flexible flatfoot deformities scheduled for subtalar screw arthroereisis surgery. Radiographs in the lateral and anteroposterior (AP) views were assessed independently in the single-leg and both-leg standing positions. Static pedobarography was performed as that for measuring weight-bearing. Standardized radiographic angles and pedobarographic data were analysed and correlated. RESULTS:There were differences in radiographic measurements between the single-leg and both-leg standing positions, including the AP talocalcaneal angle (p = 0.032), AP talus-first metatarsal base angle (p = 0.003), AP talus-first metatarsal angle (p = 0.003), lateral calcaneal pitch angle (p = 0.001), talus-first metatarsal index (p = 0.004), and talocalcaneal index (p = 0.029). Moreover, differences between these two standing modalities were found in most of the static pedobarographic data, including the contact area (p = 0001), maximal force (p = 0.001), and peak pressure (p = 0.007). Overall, medial foot pressure increased more in both-leg standing than in the single-leg standing position, whereas radiographic measurements showed a more pronounced flatfoot deformity in the single-leg standing position. The AP talus-first metatarsal angle was the only angle or index with a significant association to some pedobarographic measurements in both standing modalities. SIGNIFICANCE:As there are significant differences between single-leg standing and both-leg standing radiographic and static pedobarographic values, observers have to be precise in the definition of "weight-bearing" to gain reproducible and comparable study values in children and adults. We recommend acquiring both-leg standing foot radiographs because children with flexible flatfeet can stand more steadily in this position than in the single-leg standing position. 10.1016/j.gaitpost.2022.01.009
The Plantar Fascia Talar Head Correlation: A Radiographic Parameter With a Distinct Threshold to Validate Flatfoot Deformity and Its Corrective Surgery on Conventional Weightbearing Radiographs. Foot & ankle international BACKGROUND:Corrective surgery for flexible flatfoot deformity (FD) remains controversial, and one of the main reasons for this is the lack of standardized radiographic measurements to define an FD. Previously published radiographic parameters to differentiate between a foot with and without an FD do not have a commonly accepted and distinct threshold. METHODS:The plantar fascia-talar head correlation (PTC) with its defined threshold was assessed by measuring the distance between the medial border of the plantar fascia and the center of the talar head (DPT) on conventional dorsoplantar and lateral weightbearing radiographs; the authors were blinded to the clinical diagnosis of the 189 patients' first visits. Feet were sorted into groups with and without an FD based on their clinical examination. The effect of operative corrections of FD on the PTC was retrospectively evaluated on an additional 38 patients. RESULTS:The sensitivity of the PTC was 0.98 (95% CI: 0.9-1) and specificity 0.96 (95% CI: 0.92-0.98), respectively, to identify an FD, consistent with the clinical examination. Thirty-five of 38 surgeries sufficiently corrected the FD and the PTC comparable to that in subjects without an FD. Three corrections with a residual FD did not adequately correct the PTC. CONCLUSION:The PTC is a reliable radiographic parameter with a distinct threshold that is sensitive and specific for the differentiation of feet with and without an FD including feet with and without residual FD after corrective surgery. The PTC is applicable to monitor the needed intraoperative amount of correction using simulated weightbearing fluoroscopy. LEVEL OF EVIDENCE:Level III, diagnostic. 10.1177/10711007211052258
Weight-bearing radiographs and cone-beam computed tomography examinations in adult acquired flatfoot deformity. Shakoor Delaram,de Cesar Netto Cesar,Thawait Gaurav K,Ellis Scott J,Richter Martinus,Schon Lew C, ,Demehri Shadpour Foot and ankle surgery : official journal of the European Society of Foot and Ankle Surgeons BACKGROUND:Optimal characterization of Adult acquired flatfoot deformity (AAFD) on two-dimensional radiograph can be challenging. Weightbearing Cone Beam CT (CBCT) may improve characterization of the three-dimensional (3D) structural details of such dynamic deformity. We compared and validated AAFD measurements between weightbearing radiograph and weightbearing CBCT images. METHODS:20 patients (20 feet, right/left: 15/5, male/female: 12/8, mean age: 52.2) with clinical diagnosis of flexible AAFD were prospectively recruited and underwent weightbearing dorsoplantar (DP) and lateral radiograph as well as weightbearing CBCT. Two foot and ankle surgeons performed AAFD measurements at parasagittal and axial planes (lateral and DP radiographs, respectively). Intra- and Inter-observer reliabilities were calculated by Intraclass correlation (ICC) and Cohen's kappa. Mean values of weightbearing radiograph and weightbearing CBCT measurements were also compared. RESULTS:Except for medial-cuneiform-first-metatarsal-angle, adequate intra-observer reliability (range:0.61-0.96) was observed for weightbearing radiographic measurements. Moderate to very good interobserver reliability between weightbearing radiograph and weightbearing CBCT measurements were observed for the following measurements: Naviculocuneiform-angle (ICC:0.47), Medial-cuneiform-first-metatarsal-gapping (ICC:0.58), cuboid-to-floor-distance (ICC:0.68), calcaneal-inclination-angle(ICC:0.7), axial Talonavicular-coverage-angle(ICC:0.56), axial Talus-first-metatarsal-angle(ICC:0.62). Comparing weightbearing radiograph and weightbearing CBCT images, statistically significant differences in the mean values of parasagittal talus-first-metatarsal-angle, medial-cuneiform-first-metatarsal-angle, medial-cuneiform-to-floor-distance and navicular-to-floor-distance was observed (P < 0.05). CONCLUSION:Moderate to very good correlation was observed between certain weightbearing radiograph and weightbearing CBCT measurements, however, significant difference was observed between a number of AAFD measurements, which suggest that 2D radiographic evaluation could potentially underestimate the severity of AAFD, when compared to 3D weightbearing CT assessment. 10.1016/j.fas.2020.04.011
Response to "Letter Regarding: First-Ray Radiographic Changes After Flexible Adult Acquired Flatfoot Deformity Correction". Foot & ankle international 10.1177/10711007221077050
Assessment of Flatfoot Deformity Using Digitally Reconstructed Radiographs: Reliability and Comparison to Conventional Radiographs. Foot & ankle international BACKGROUND:Digitally reconstructed radiographs (DRRs) generated from weightbearing computed tomography (WBCT) may potentially substitute for weightbearing plain radiographs (XRs) but have not been clinically validated. This study aims to test the reliability of 6 radiographic parameters of progressive collapsing foot deformity (PCFD) as measured on DRR, to investigate whether DRR represents comparably to XR through the same measurements, and to compare agreement of DRR and XR measurements of a standardized arch height parameter with reference measurements made on WBCT. METHODS:DRR generated from preoperative WBCT of 71 patients (72 feet) treated surgically for PCFD were retrospectively compared with preoperative weight-bearing XR after exclusion criteria were applied. Six radiographic measurements were performed, including Meary angle, calcaneal pitch (CPA), medial cuneiform height (MCH), AP talar-first metatarsal angle (T-1MT), talonavicular coverage (TNCA), and talar incongruency (TIA). Arch height was measured on XR, DRR, and WBCT using a validated, standardized, navicular-based index. Intraclass correlation coefficients assessed DRR intraobserver and interobserver reliability. Paired samples tests tested differences between XR and DRR. Bland-Altman limits of agreement analysis compared DRR and XR agreement with WBCT measurements. RESULTS:Measurements were within standard PCFD ranges on XR and DRR. All measurements demonstrated excellent intrarater reliability and good to excellent interrater agreement, consistent with previous literature on XR. No differences were found for Meary, CPA, or TNCA. Minor differences were observed for MCH, T-1MT, and TIA. DRR measurements demonstrated greater agreement with WBCT than XR measurements. CONCLUSION:DRR from WBCT may be a promising substitute for XR in the clinical evaluation of PCFD. Radiographic measurements made on DRR demonstrated good to excellent reliability. Although small differences were found between XR and DRR for certain measurements, DRR more accurately represented medial arch anatomy compared to gold standard WBCT data than XR. If validated as a clinical substitute, DRR could eventually obviate XR where WBCT is available. LEVEL OF EVIDENCE:Level III, retrospective cohort study. 10.1177/10711007221089260
Current concept review: acquired adult flatfoot deformity. Pinney Stephen J,Lin Sheldon S Foot & ankle international 10.1177/107110070602700113
Operative management options for symptomatic flexible adult acquired flatfoot deformity: a review. Zaw Htwe,Calder James D F Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA 10.1007/s00167-009-1015-6
The Flatfoot: Even After Decades of Work, We Still Need Help Understanding It. Ellington J Kent Foot and ankle clinics 10.1016/j.fcl.2017.06.001
Classifications in Brief: Johnson and Strom Classification of Adult-acquired Flatfoot Deformity. Abousayed Mostafa M,Tartaglione Jason P,Rosenbaum Andrew J,Dipreta John A Clinical orthopaedics and related research 10.1007/s11999-015-4581-6
Acquired flatfoot in adults due to dysfunction of the posterior tibial tendon. Pomeroy G C,Pike R H,Beals T C,Manoli A The Journal of bone and joint surgery. American volume 10.2106/00004623-199908000-00014
Adult Acquired Flatfoot Deformity: Anatomy, Biomechanics, Staging, and Imaging Findings. Flores Dyan V,Mejía Gómez Catalina,Fernández Hernando Moisés,Davis Michael A,Pathria Mini N Radiographics : a review publication of the Radiological Society of North America, Inc Adult acquired flatfoot deformity (AAFD) is a common disorder that typically affects middle-aged and elderly women, resulting in foot pain, malalignment, and loss of function. The disorder is initiated most commonly by degeneration of the posterior tibialis tendon (PTT), which normally functions to maintain the talonavicular joint at the apex of the three arches of the foot. PTT degeneration encompasses tenosynovitis, tendinosis, tendon elongation, and tendon tearing. The malaligned foot is initially flexible but becomes rigid and constant as the disorder progresses. Tendon dysfunction commonly leads to secondary damage of the spring ligament and talocalcaneal ligaments and may be associated with injury to the deltoid ligament, plantar fascia, and other soft-tissue structures. Failure of multiple stabilizers appears to be necessary for development of the characteristic planovalgus deformity of AAFD, with a depressed plantar-flexed talus bone, hindfoot and/or midfoot valgus, and an everted flattened forefoot. AAFD also leads to gait dysfunction as the foot is unable to change shape and function adequately to accommodate the various phases of gait, which require multiple rapid transitions in foot position and tone for effective ambulation. The four-tier staging system for AAFD emphasizes physical examination findings and metrics of foot malalignment. Mild disease is managed conservatively, but surgical procedures directed at the soft tissues and/or bones become necessary and progressively more invasive as the disease progresses. Although much has been written about the imaging findings of AAFD, this article emphasizes the anatomy and function of the foot's stabilizing structures to help the radiologist better understand this disabling disorder. RSNA, 2019. 10.1148/rg.2019190046