Fig. 1

Lower extremity marker placement: 20 retroreflective markers based on the modified plug-in-gait marker system. These markers were placed laterally on posterior superior iliac spine, anterior superior iliac spine, lateral thigh, lateral femoral epicondyle, lateral shank, lateral malleolus, second metatarsal head, and calcaneus, the fifth metatarsal, medial malleolus, and medial femoral epicondyle