Kinematics of the Ankle/Foot Complex—Part 2: Pronation and Supination

Abstract

The influence of pronation and supination of the foot on the joints of the ankle/foot complex was analyzed three dimensionally by roentgen stereophotogrammetry in eight healthy volunteers. Radiopaque markers were introduced into the tibia, talus, calcaneus, navicular, medial cuneiform, and first metatarsal bones. The subjects stood on a platform that was tilted in 10°-steps from 20° of pronation to 20° of supination. Pairs of x-ray exposures were made in each position. Calculation of resulting joint deviations from the neutral position showed that the largest amounts of motion occurred in the talonavicular joint followed by the talocalcaneal joint, in the latter case mainly in supination. The joints proximal and distal to the medial cuneiform also participated substantially in the total motion registered. The tibia showed an average of 0.2° of external rotation for each degree of supination of the foot.