人体背部负重对于步态特征的影响及相应补偿策略的实验研究

人体背部负重量大小对步态特征的影响及相应补偿策略的研究对于自主式两足步行机器人的设计和平衡控制以及军人体能训练均有重要意义。从实验的角度对受试者分别背部负重6kg、12kg和25kg时的步态特征和补偿策略进行了研究。结果表明：人体背部负重后会引起步态特征的明显变化，这种差异主要表现在髋关节、膝关节以及上躯干的摆动角位移变化。负重后，人体的平均步速明显降低，但其步长的变化并不明显。人体对于负重的响应特征与受试者的肌肉强度是密切相关的。为有效补偿背部负重所产生的影响，人体利用多关节协调运动来进行补偿。但各个关节的贡献不同，其补偿主要由髋关节、膝关节以及上躯干的摆动来完成，踝关节的贡献相对较小。背部负重后总质心向前的调整主要是由上躯干的向前倾斜来实现。负重量越大，上躯干向前倾斜的平均角位移越大。为减少负重后的冲击对关节的损伤，脚跟触地时，可利用髋关节和膝关节的弯曲刚度来吸收冲击。

The Effects of Backpack Loading on the Gait and Corresponding Compensatory Strategy

This study was designed to determine the effect of backpack loading on the gait pattern and corresponding compensatory strategy, which is important to the balance control of biped robot and military training. Five healthy subjects were instructed to walk at their preferred speed on level pathway taking three different loads, i.e. 6kg, 12kg and 25kg, on their backs. The results showed that the gait pattern was apparently influenced, and the dominant effects were found to be the flexion of hip, knee joints and pitch angle of torso. The stride speed decreaseed apparently with loading on their backs, but the stride length showed less changes. Besides, the responses to taking loads might be influenced by the strength of body. An apparent multi joints coordination motor mode was employed to compensate the influences of loading, however, their contributions are different; hip, knee joints and torso pitch made dominant contributions to the compensation while ankle joints made minor. The anterior pitch of upper torso could be employed to adjust the overall center of mass while loading on their backs, the larger the magnitude of loading on their backs, the larger the anterior pitch angle of torso. After the heel touched the ground, the flexion of hip and knee joints were effective for the shock absorption, which means that the stiffness of hip and knee joints can be used to absorb the shock and avoid the trauma of each joints.