Three-dimensional kinematics and dynamics of the foot during walking: a model of central control mechanisms
Three-dimensional kinematics and dynamics of the foot during walking: a model of central control mechanisms
复制标题
步行过程中足部的三维运动学和动力学：中央控制机制模型
作者：
Y. Osaki;M. Kunin;B. Cohen;T. Raphan
脚是行走过程中身体和支撑面之间的关键界面，但没有一致的框架来模拟站立和摆动阶段的动力学。为了建立这个框架，我们使用运动检测系统（OPTOTRAK）研究了受试者在跑步机上行走时在三个维度上足部运动的旋转和平移动力学。位置、速度和持续时间根据腿长和重力进行标准化。足部位置和足尖离地时的旋转与步行速度密切相关。脚趾间隙处的脚间距随着步行速度的增加而增加，但脚趾的内侧-外侧和垂直位置没有改变。沿着前后方向的相平面轨迹，即脚趾速度与位置的关系图，在摆动阶段是圆形的，半径与行走速度成正比。峰值向前、横向和向上速度与相应的偏移线性相关，形成主序列。二阶模型预测了脚趾位置和速度的变化，以及作为步行速度函数的持续时间的近似双曲线递减。该模型表明，脚在站立阶段以过阻尼方式受到控制，而在摆动期间以反馈控制的无阻尼摆方式受到控制。数据和模型表明，由站立阶段行走速度设定的足部在脚趾离地时的状态决定了摆动阶段的动态。因此，除了确定运动学之外，步行速度在确定摆动阶段足部运动的相平面轨迹和主序列关系方面也起着至关重要的作用。
The foot is a critical interface between the body and supporting surface during walking, but there is no coherent framework on which to model the dynamics of the stance and swing phases. To establish this framework, we studied the rotational and translational dynamics of foot movement in three dimensions with a motion detection system (OPTOTRAK), while subjects walked on a treadmill. Positions, velocities, and durations were normalized to leg-length and gravity. Foot position and rotation at toe-off were closely related to walking velocity. Foot pitch at toe clearance increased with walking velocity, but the medial–lateral and vertical toe positions were unaltered. Phase–plane trajectories along the fore-aft direction, i.e., plots of toe velocity versus position, were circular during the swing phases, with radii proportional to walking velocity. Peak forward, lateral, and upward velocities were linearly related to corresponding excursions, forming main sequences. A second order model predicted the changes in toe position and velocity, and the approximately hyperbolic decrements in duration as a function of walking velocity. The model indicates that the foot is controlled in an overdamped manner during the stance phase and as a feedback-controlled undamped pendulum during the swing. The data and model suggest that the state of the foot at toe-off, set by walking velocity during the stance phase, determines the dynamics of the swing phase. Thus, in addition to determining locomotion kinematics, walking velocity plays a critical role in determining the phase–plane trajectories and main sequence relationships of foot movements during the swing phases.
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影响因子：
2.4
作者：
Donelan, JM;Shipman, DW;Kuo, AD
通讯作者：
Kuo, AD
DOI：
10.1115/1.1372322
发表时间：
2001-06-01
影响因子：
1.7
作者：
Kuo, AD
通讯作者：
Kuo, AD
人类行走和跑步的质心轨迹的决定因素。
DOI：
10.1242/jeb.201.21.2935
发表时间：
1998
期刊：
The Journal of experimental biology
影响因子：
--
作者：
Lee,CR;Farley,CT
通讯作者：
Farley,CT
影响因子：
2.4
作者：
Bauby, CE;Kuo, AD
通讯作者：
Kuo, AD