The aim of this study was to compare the compressive and shear forces of
ankle joint in subjects with flat foot and pes cavus foot. 30 female university
students (10 subjects with flat feet, 10 subjects with pes cavus feet, 10
subjects with normal feet) (mean age 23±1.7 year, height 165±2.5 cm and
weight 53±2.5 kg) participated in this study. Compressive and shear forces
of ankle joint were calculated using inverse dynamic method. Navicular-
Drop Test was used to measure the arch rate of the foot. One-factor ANOVA
with repeated measures was used to test the hypotheses (P􀂔0.05). The
statistical results showed a significant difference between pes cavus and
normal feet, pes cavus and flat feet as well as between normal feet and flat
feet in the compressive force of the ankle joint (P<0.001). Also, findings
showed a significant difference between pes cavus feet and flat feet
(P=0.029) and normal feet and flat feet in the shear force of the ankle joint
(P=0.001). No significant difference was observed between normal feet and
pes cavus feet in the shear force of the ankle joint (P=0.163). Accordingly,
increasing compressive force of ankle joint could be a predisposing factor
to ankle sprain and bone injuries in pes cavus feet.