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Objective To collect the kinematics and kinetics functional parameters of healthy human lower limbs during stair ascent and descent, so as to provide data for designing the gait trajectory and selecting the driving components of the exoskeleton walker to achieve the motion of stair climbing. Methods Common staircase as an experimental setup was designed, and the three-dimensional (3D) motion capture system and 3D force plate were used to simultaneously measure the ankle, knee, hip motion information during stair ascent and descent. The movement characteristics of the lower limb during stair climbing was analyzed by SPSS statistical software and Origin graphics software, and the functional parameters during stair ascent and decent were also compared and analyzed. Results The joint angle at the sagittal plane, joint moment variation with gait and activity limits in lower limbs of healthy youth during stair ascent and descent were obtained by the experiment. The ranges of motion in ankle，knee and hip joints during stair ascent were -10.66°-13.26°, 6.85°-88.92°, 1.31°-50.18°,while those during stair descent were -37.42°-27.18°,9.83°-95.53°,8.01°-31.62°.The maximum ankle, knee and hip joint moment during stair ascent and descent were 1.788, 1.121, 0.946 N•m/kg, respectively. Conclusions The gait parameters variation with gait and the joint range of motion in human lower limb were significantly different during stair ascent and descent. Separate design targeting at stair ascent or stair descent is required for gait planning of walking aids, and the selection of driving element should consider the maximum moment in each joint during stair ascent and descent.
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Despite their wide clinical application and success, our understanding of the effects of insoles is relatively limited. The purpose of this study was to assess the biomechanical effects of wearing lateral/medial wedged insoles on subtalar and knee joints during normal walking. Motion analysis was conducted with a 3D motion-analysis system and a ground reaction force analysis using force plate when subjects walked with three different insole conditions : 5-degree medial wedge, no wedge, and 5-degree lateral wedge. Significant differences were found in subtalar or ankle joint motion in coronal and sagittal planes compared with the no-wedge condition. No differences were found in knee joint motion in the coronal and axial planes. The lateral-wedge insole reduced the knee varus moment and increased subtalar pronation moment in mid-stance during walking. At footstrike, however, the lateral wedge increased the knee varus moment and reduced the subtalar supination moment. The medial-wedge insole increased the knee varus moment and decreased subtalar pronation moment during the mid-stance phase. However, the medial wedge reduced the knee varus moment and increased subtalar supination moment at footstrike. The results of this study indicate that the influence of the insoles varied during the stance phase. Therefore, it is requested to select the shape of insole based on the injury mechanism, the location of the pain and the injury prevention.
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@#ObjectiveTo analyze the biomechanics of ascending and descending stairs.MethodsThe moment of force of knee joint and contract strength of quadriceps muscles were analyzed by three dimensional motion analysis system and electromyograph (EMG) in three healthy men.ResultsFor the moment of force of knee joint, there were differences among different styles of ascending and descending stairs, but there were no differences in angles of knee joint flexion. The contract strength of quadriceps muscles during ascending stairs was stronger than that during descending stairs.Conclusion There are differences of knee joint moment and quadriceps muscles activities among 4 strategies during descending, and it is shown that quadriceps muscles' activities and knee joint moment became smaller during forward stepping, double stepping on one stair, side stepping, and 45°side stepping in sequence during descending stairs.