Objective Foot pronation is a common lower limb deformity that can affect human movement mechanics. Therefore, the aim of this study was to compare the frequency spectrum of ground reaction forces (GRFs) during walking with and without the use of an anti-pronation insole in individuals with pronated feet.
Methods Twenty men with pronated feet (mean age: 21.12 ± 1.47 years; mean weight: 71.52 ± 5.18 kg; mean height: 178.15 ± 4.18 cm) voluntarily participated in this study. A foot scan system was used to measure the frequency spectrum of GRFs during walking, both with and without the anti-pronation insole. A paired t-test was conducted for statistical analysis.
Results The results showed that the frequency at 99.5% power in the vertical component of the GRFs was significantly higher when using the insole compared to without it (p = 0.047, d = 0.85). Additionally, the frequency at 99.5% power was significantly higher with the insole in the big toe (p = 0.001, d = 0.30) and in toes 2 to 5 (p = 0.001, d = 0.29). Moreover, the frequency at 99.5% power in the vertical component of the first to fourth metatarsal regions was also significantly higher (p < 0.05).
Conclusion The use of orthopedic insoles in individuals with pronated feet alters the biomechanical characteristics of gait and appears to enhance the distribution of vertical forces and the engagement of various foot structures.