Inverse kinetic and kinematic analysis of drop-foot patient's walking

The purpose of this study was to quantify the effect of drop-foot on biomechanical properties of human gait such as heel altitude and sagittal angles and moments of lower limb joints, during a gait cycle. Two subjects with almost the same anthropometric parameters consisted of a healthy and a unilateral drop-foot patient were asked to walk at a self selected speed over two recessed force platforms, while the movements were recorded by six infrared cameras. Joint angles and moments were calculated by inverse kinematics and inverse dynamics, using OpenSim software. The study shows, delayed incomplete swing phase in leg's motion. During the gait cycle, besides excessive hip flexion, no hip extension was observed in the affected leg. Knee flexion curve for this leg shows one peak trend instead of normal double peak behavior. The planter flexion moment of affected ankle was much less than its normal value. In the unaffected leg motion late heel strike was observed. The patient was able to lift that leg to only half of the normal value.