Modular control of limb movements during human locomotion
Modular control of limb movements during human locomotion
复制标题
DOI：
10.1523/jneurosci.2644-07.2007
复制
发表时间：
2007-10-10
影响因子：
5.3
通讯作者：
Lacquaniti, Francesco
中科院分区：
文献类型：
--
作者：
Ivanenko, Yuri P.;Cappellini, Germana;Lacquaniti, Francesco
CNS可以通过模块分解来控制复杂的相互作用的想法已经受到了相当大的关注。我们通过研究肢体运动学来探索人类运动的这一想法。在人类运动过程中，肢体段的协调已被证明遵循平面定律，以不同的速度，方向和身体卸载水平行走。我们比较了不同步态的协调性。八名受试者被要求以不同的速度在跑步机上行走和跑步，或者以首选的速度在地面上行走，跑步和跳跃。为了探索对肢体运动的各种限制，我们还记录了跨越障碍物，膝盖弯曲行走和体重支撑的空气步。我们发现依赖于速度的协方差平面之间的差异很小，但依赖于步态的差异。在每种情况下，我们可以用肢体长度和方向轨迹的加权和来拟合平面轨迹。这表明，肢体长度和方向可能提供独立的预测肢体协调。我们进一步测试了这一点，让受试者步，跑，跳到位，从而只改变肢体长度和保持肢体方向固定，也通过与膝盖锁定，以保持肢体长度不变，而不同的方向行军。结果是一致的模块化控制的肢体运动，肢体运动的结果从一个叠加的单独的长度和方向相关的角度协方差。这一假设在动物研究中得到了支持，即肢体本体感受也可能根据这些全局肢体参数进行编码。
The idea that the CNS may control complex interactions by modular decomposition has received considerable attention. We explored this idea for human locomotion by examining limb kinematics. The coordination of limb segments during human locomotion has been shown to follow a planar law for walking at different speeds, directions, and levels of body unloading. We compared the coordination for different gaits. Eight subjects were asked to walk and run on a treadmill at different speeds or to walk, run, and hop over ground at a preferred speed. To explore various constraints on limb movements, we also recorded stepping over an obstacle, walking with the knees flexed, and air-stepping with body weight support. We found little difference among covariance planes that depended on speed, but there were differences that depended on gait. In each case, we could fit the planar trajectories with a weighted sum of the limb length and orientation trajectories. This suggested that limb length and orientation might provide independent predictors of limb coordination. We tested this further by having the subjects step, run, and hop in place, thereby varying only limb length and maintaining limb orientation fixed, and also by marching with knees locked to maintain limb length constant while varying orientation. The results were consistent with a modular control of limb kinematics where limb movements result from a superposition of separate length- and orientation-related angular covariance. The hypothesis finds support in the animal findings that limb proprioception may also be encoded in terms of these global limb parameters.