MECHANICAL ANALYSIS OF THE LANDING PHASE IN HEEL TOE RUNNING
MECHANICAL ANALYSIS OF THE LANDING PHASE IN HEEL TOE RUNNING
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DOI：
10.1016/0021-9290(92)90022-s
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发表时间：
1992-03-01
影响因子：
2.4
通讯作者：
NIGG, BM
中科院分区：
文献类型：
--
作者：
BOBBERT, MF;YEADON, MR;NIGG, BM
跑步力学分析的结果可能有助于寻找跑步损伤的病因。 在这项研究中，力学分析的着陆阶段的三个训练有素的脚跟脚趾跑步者，运行在他们喜欢的速度和风格。 身体被建模为一个系统的七个链接的刚性段，并使用200 Hz的视频分析监测这些段的标记的位置。 使用测力板收集关于地面反作用力矢量的信息。 将节段运动学与地面反作用力数据相结合，计算节段间的净力和力矩，发现地面反作用力矢量F（z）的垂直分量在着陆后约25 ms达到第一个峰值。 出现该峰值是因为，在支撑腿中，膝关节的垂直加速度相对于踝关节的垂直加速度没有通过小腿的旋转而减小，使得支撑腿段与地板碰撞。 然而，支撑大腿的旋转减小了髋关节相对于膝关节的垂直加速度，从而在前40 ms期间在限制垂直力方面起重要作用。在触地后的40 ms和100 ms之间，垂直力主要受到支撑小腿的旋转的限制。在F（z）达到其第一峰值的瞬间，围绕支撑腿的踝关节、膝关节和髋关节的净力矩实际上为零。 膝关节的净力矩从触地时的-100 Nm（屈曲）变为触地后50 ms的+200 Nm（伸展）。 这些变化太快，不能用肌肉激活水平的变化来解释，而是归因于预激活的膝屈肌和膝伸肌的弹簧样行为。 这些结果意味着，被调查的跑步者没有机会在接触阶段的第一部分控制身体部分的旋转，除了在触地前选择一定的身体几何形状和肌肉（共）激活水平。
Results of mechanical analyses of running may be helpful in the search for the etiology of running injuries. In this study a mechanical analysis was made of the landing phase of three trained heel-toe runners, running at their preferred speed and style. The body was modeled as a system of seven linked rigid segments, and the positions of markers defining these segments were monitored using 200 Hz video analysis. Information about the ground reaction force vector was collected using a force plate. Segment kinematics were combined with ground reaction force data for calculation of the net intersegmental forces and moments.The vertical component of the ground reaction force vector F(z) was found to reach a first peak approximately 25 ms after touch-down. This peak occurs because, in the support leg, the vertical acceleration of the knee joint is not reduced relative to that of the ankle joint by rotation of the lower leg, so that the support leg segments collide with the floor. Rotation of the support upper leg, however, reduces the vertical acceleration of the hip joint relative to that of the knee joint, and thereby plays an important role in limiting the vertical forces during the first 40 ms. Between 40 and 100 ms after touch-down, the vertical forces are mainly limited by rotation of the support lower leg.At the instant that F(z) reaches its first peak, net moments about ankle, knee and hip joints of the support leg are virtually zero. The net moment about the knee joint changed from - 100 Nm (flexion) at touch-down to + 200 Nm (extension) 50 ms after touch-down. These changes are too rapid to be explained by variations in the muscle activation levels and were ascribed to spring-like behavior of pre-activated knee flexor and knee extensor muscles. These results imply that the runners investigated had no opportunity to control the rotations of body segments during the first part of the contact phase, other than by selecting a certain geometry of the body and muscular (co-)activation levels prior to touch-down.