Voluntary and reactive recruitment of locomotor muscle synergies during perturbed walking.
Voluntary and reactive recruitment of locomotor muscle synergies during perturbed walking.
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DOI：
10.1523/jneurosci.6344-11.2012
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发表时间：
2012-08-29
期刊：
影响因子：
--
通讯作者：
Ting LH
中科院分区：
文献类型：
--
作者：
Chvatal SA;Ting LH
肌肉成组的模块化控制，通常被称为肌肉协同作用，已经被提出为运动的健壮控制提供动作的运动曲目。然而，尚不清楚在一项任务中确定的肌肉协同效应是否也被不同的神经通路招募，这些神经通路服从于其他运动行为。我们测试了这样一种假设，即人类对行走的自愿和反应性改变是运动肌肉协同作用的重新招募。我们记录了受试者以两种不同的速度行走7.5米时右腿16块肌肉的活动情况。为了引发第二种运动行为，在路径中途，我们在四个基本方向中的每一个方向上施加坡道和保持支撑面的平移扰动。运动肌肉协同作用在时间上的招募的变化可以解释跨步肌肉活动的周期变化。运动肌肉协同作用也在步态的非典型阶段被招募，这既考虑了扰动前的预期步态修改，也考虑了对扰动的反应性反馈反应。我们的发现与这样的观点是一致的，即不同的神经路径可以招募到一个共同的空间固定的运动肌肉协同效应池，包括用于行走的中央模式生成器，用于平衡控制的脑干路径，以及调节自愿步态修改的皮质路径。结合电生理研究，我们的工作表明，肌肉协同作用可能提供一个运动子任务库，可以通过平行的下行路径灵活地招募这些子任务，以在上肢和下肢产生各种复杂的自然动作。
The modular control of muscles in groups, often referred to as muscle synergies, has been proposed to provide a motor repertoire of actions for the robust control of movement. However it is not clear whether muscle synergies identified in one task are also recruited by different neural pathways subserving other motor behaviors. We tested the hypothesis that voluntary and reactive modifications to walking in humans result from the recruitment of locomotor muscle synergies. We recorded the activity of 16 muscles in the right leg as subjects walked a 7.5 m path at two different speeds. To elicit a second motor behavior, midway through the path we imposed ramp and hold translation perturbations of the support surface in each of four cardinal directions. Variations in the temporal recruitment of locomotor muscle synergies could account for cycle-by-cycle variations in muscle activity across strides. Locomotor muscle synergies were also recruited in atypical phases of gait, accounting for both anticipatory gait modifications prior to perturbations and reactive feedback responses to perturbations. Our findings are consistent with the idea that a common pool of spatially-fixed locomotor muscle synergies can be recruited by different neural pathways, including the central pattern generator for walking, brainstem pathways for balance control, and cortical pathways mediating voluntary gait modifications. Together with electrophysiological studies, our work suggests that muscle synergies may provide a library of motor subtasks that can be flexibly recruited by parallel descending pathways to generate a variety of complex natural movements in the upper and lower limbs.