Objective To investigate differences in the relative sizes of the ankle-stabilizing muscles in individuals with versus without flexible flat feet and to determine predictors of symptom severity.
Methods This cross-sectional study included 30 patients with symptomatic flexible flat feet and 24 normal controls. The following were evaluated: foot posture index, resting calcaneal stance position angle, radiographic findings (calcaneal pitch, Meary’s angle, talocalcaneal angle, talonavicular coverage angle [TNCA]), foot function index (FFI), and cross-sectional areas (CSA) of the tibialis anterior (TA), tibialis posterior (TP), and peroneus longus (PL) upon ultrasonographic examination. To address morphometric differences among participants, individual muscle measurements were normalized to proportions of total muscle CSA. Between-group differences were evaluated with independent t-tests. Correlations between muscle ratios, radiographic parameters, and FFI scores were investigated. Logistic regression analysis was performed to determine which parameters predicted severe symptoms.
Results The relative size of the TP was significantly greater and those of the TA and PL were significantly smaller in patients with flat feet than in normal controls. Correlations were found among relative muscle CSA ratios, radiographic parameters, and FFI score. Linear regression analysis confirmed that the TNCA and the relative CSA of the PL were independent predictors of symptom severity.
Conclusion This study found significant differences in the relative CSAs of the ankle muscles in patients with flexible flat feet versus individuals without flat feet; these differences were significantly correlated with anatomic abnormalities. Symptoms were more severe in patients with relatively greater forefoot abduction and relatively smaller PL.
Citations
Citations to this article as recorded by
Does severity of the flatfoot deformity affect pain and mobility in adolescents with symptomatic flatfoot Matthew William, Daniel E. Pereira, Beltran Torres-Izquierdo, Claire Schaibley, Pooya Hosseinzadeh Journal of Pediatric Orthopaedics B.2025; 34(2): 189. CrossRef
정상발 및 평발 집단의 발목관절 토크 및 만성발목불안정증(CAI)의 특성 차이 석경 안, 상근 조, 승재 김 The Korean Journal of Physical Education.2024; 63(5): 339. CrossRef
Relation of Flatfoot Severity with Flexibility and Isometric Strength of the Foot and Trunk Extensors in Children Min Hwan Kim, Sangha Cha, Jae Eun Choi, Minsoo Jeon, Ja Young Choi, Shin-Seung Yang Children.2022; 10(1): 19. CrossRef
Effect of Foot Orthoses in Children With Symptomatic Flexible Flatfoot Based on Ultrasonography of the Ankle Invertor and Evertor Muscles Dong Joon Cho, So Young Ahn, Soo-Kyung Bok Annals of Rehabilitation Medicine.2021; 45(6): 459. CrossRef
Biomechanical Evidence From Ultrasonography Supports Rigid Foot Orthoses in Children With Flatfoot Joon-Ho Shin Annals of Rehabilitation Medicine.2021; 45(6): 411. CrossRef