Effects of Treadmill Speed on Joint Angles of Human Lower Limbs During Walking

In order to study the influence of different walking speeds on locomotive information of healthy human lower limbs in the sagittal plane, frontal plane and transversal plane, VICON three dimensional motion capturing system was adopted to measure the movement information of seven healthy human pelvis, hip, knee and ankle, when human was walking on the treadmill at 1km/h, 2km/h, 3km/h. The pelvic, hip, knee and ankle kinematics and the relationship of joint angles of lower limbs in the sagittal plane, frontal plane and transversal plane were analyzed. The results show that for three joints of lower limb, increasing of the treadmill velocity increases the maximum angle of the flexion and variation range of joint in the sagittal plane while increasing velocity has little impact on the shapes of the curves except curves of hip joint in the transversal plane; regarding pelvic movement, increasing velocity has small effects on amplitude and shape of curves of pelvis motion; with velocity increasing, the modes of joint movement kept invariant, knee movement is stabilized and ankle movement is complicated. The results provide kinematics information for designing and controlling lower extremity rehabilitative robot.