Ground reaction forces intersect above the center of mass in single support, but not in double support of human walking
Ground reaction forces intersect above the center of mass in single support, but not in double support of human walking
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DOI：
10.1016/j.jbiomech.2021.110387
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发表时间：
2021-03-30
影响因子：
2.4
通讯作者：
Abel, Rainer
中科院分区：
文献类型：
--
作者：
Vielemeyer, Johanna;Mueller, Roy;Abel, Rainer
有各种各样的简化模型来描述人类行走的平衡策略。在一个模型中，假设地面反作用力在整个步幅期间指向质心上方的点（虚拟枢轴点）。在几个实验研究中观察到这一点，但仅限于单一支持相。目前还没有具体考虑人类是否在双重支持阶段使用相同的稳定策略。为了分析这一点，9名志愿者以自选的速度行走，同时测量动力学和运动学数据。我们发现，在对比的单支撑阶段，其中的虚拟枢轴点是显着高于质心，在双支撑阶段的人类行走的地面反作用力点周围的质量中心有一个小的蔓延（R-2 = 92.5%）。不同支撑阶段虚拟支点的高度不同可能是由于质心的垂直运动引起的，在双支撑阶段质心的垂直运动幅度较小。这也反映在地面反作用力中，由此水平和垂直地面反作用力的比率可以解释虚拟枢轴点的高度。在双支撑阶段中，由于接触时间较短和制动脉冲延迟，与单支撑阶段相比，比率向有利于水平分量的方向移动。因此，整个身体似乎围绕质心旋转，这可能使所需的能量最小化。(C)2021爱思唯尔有限公司保留所有权利。
There are various simplifying models that describe balance strategies of human walking. In one model it is assumed that ground reaction forces are directed to a point (virtual pivot point) above the center of mass during the whole stride. This was observed in several experimental investigations, but only for the single support phase. It has not yet been concretely considered whether humans use the same stabilization strategy during the double support phase. For analyzing this, nine volunteers walked at self-selected speed while kinetic and kinematic data were measured. We found that in contrast to the single support phase, where the virtual pivot point was significantly above the center of mass, in the double support phase of human walking the ground reaction forces point around the center of mass with a small spread (R-2 = 92.5%). The different heights of the virtual pivot point in the different support phases could be caused by the vertical movement of the center of mass, which has a lower amplitude in the double support phase. This is also reflected in the ground reaction forces, whereby the ratio of the horizontal and vertical ground reaction forces can explain the height of the virtual pivot point. In the double support phase the ratio is shifted in favor of the horizontal component compared to the single support phase, because of a shorter contact time and a delayed braking impulse. Thus, the whole body seems to rotate around the center of mass, which presumably minimizes required energy. (C) 2021 Elsevier Ltd. All rights reserved.