A Comparison of the Stiffness of Ankle Joint in Individuals with Normal Feet, Flat Feet and Pes Cavus in Gait Initiatio

The aim of this study was to compare the stiffness of ankle joint in individuals with normal feet, flat feet and pes cavus in gait initiation. 30 female students (10 subjects with flat feet, 10 subjects with pes cavus, 10 subjects with normal feet, mean age 23±1.7 yr, height 165±2.5 cm and weight 53±2.5 kg) participated in this study. Stiffness was calculated using the ratio of muscle torque to the angular displacement of the joint. Navicular-drop test was used to measure the arch rate of the foot. One-way analysis of variance (ANOVA) was used to test the hypotheses (P<0.05). The statistical results showed a significant difference among three groups in the stiffness of the ankle joint (P<0.001). Results of Tukey post hoc test showed that mean stiffness of ankle joint in subjects with pes cavus was 61.97% more than those with flat feet and 43.9% more than those with normal feet and mean stiffness of ankle joint in subjects with normal feet was 41.72% more than those with flat feet. Findings showed that a change in the arch of foot change changed the stiffness as well. Since the stiffness can affect the incidence of vulnerability of soft and hard tissues, coaches are recommended to pay attention to this biomechanical factor in training programs for individuals with foot deformities.