THE EFFECT OF FOOT LANDING POSITION ON ANGULAR KDNEMATICS OF THE FOOT-ANKLE COMPLEX DURING GAIT

Abstract

INTRODUCTION The foot landing position (FLP) at touchdown has been hypothesized to be a factor that excessively increases the magnitude of eversion during gait (Inman, 198 1) and stressing the tissues of the foot-ankle complex . (Hamilton, 1985). The purpose of this study was to determine if different FLP during gait would affect the angular kinematics of the foot ankle-complex. METHODS Thirty female participants demonstrating neutral (Neu), toe-in (Toe-1) and toe-out (Toe-0) FLP (5.70 ± l.Oº, -3.80 ± 2.00 and 14.30±2.70, respectively) performed 10 trials of barefoot walking. The locations of markers placed on the foot and leg segments were captured by four digital (100 fps) cameras during the stance phase. Statistical comparisons (p≤ 0.05) among FLP groups were performed using single factor ANOVAs and when appropriate, Tukey's HSD. RESULTS AND DISCUSSION When compared to the Neu values, both non-neutral groups exhibited differences for position but not velocity (Table 1). The similarity pf defined displacement of the rearfoot during the contact phase suggest that all groups allowed the forefoot to adequately adapt to the surface (Inman, 1981; Donatelli, 1990). Excessive rigidity or rigidity that occurs too early limits the range of motion may cause abnormal compensatory positioning within the foot (Donatelli, 1990). The Toe-1 and Toe-0 groups exhibited an inverted position later and earlier in the stance phase, respectively, suggesting improper timing for developing foot rigidity. A slight tendency may exist for the Toe-1 group to allow less relative transverse rotations (Ab/Ad) between the tibia and the foot.