Muscle synergy organization is robust across a variety of postural perturbations
Muscle synergy organization is robust across a variety of postural perturbations
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DOI：
10.1152/jn.00810.2005
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发表时间：
2006-09-01
影响因子：
2.5
通讯作者：
Ting, Lena H.
中科院分区：
文献类型：
--
作者：
Torres-Oviedo, Gelsy;Macpherson, Jane M.;Ting, Lena H.
我们最近发现，四个肌肉协同作用可以重现多种肌肉激活模式的猫在姿势反应，以支持表面翻译。我们现在测试功能性肌肉协同作用的鲁棒性，其指定在几种生物力学不同条件下姿势响应期间产生的肌肉分组和主动力向量。我们的目的是确定这种协同作用是否代表一个广义的控制策略，姿势控制，或者如果他们只是特定于每个姿势的任务。分析了在不同前后爪距离下对多方向平移的姿势反应和在首选站立距离下对多方向旋转的姿势反应。需要五个协同作用，以充分重建反应的翻译在首选的立场距离-四个类似于我们以前的分析翻译，而第五占新增加的背景活动在安静的立场。这五个控制协同作用可以解释> 80%的总变异性或r（2）> 0.6的肌电和力调谐曲线的所有其他实验条件。力被成功地重建，但只有当它们被引用到一个坐标系，随着站立距离的变化与肢体轴旋转。最后，在肌肉协同数量、协同激活模式和协同力矢量方面，所有六只猫的大部分功能性肌肉协同作用都是相似的。跨扰动类型、姿势和动物的协同组织的稳健性表明，控制任务变量的肌肉协同是CNS用于平衡控制的一般构造。
We recently showed that four muscle synergies can reproduce multiple muscle activation patterns in cats during postural responses to support surface translations. We now test the robustness of functional muscle synergies, which specify muscle groupings and the active force vectors produced during postural responses under several biomechanically distinct conditions. We aimed to determine whether such synergies represent a generalized control strategy for postural control or if they are merely specific to each postural task. Postural responses to multidirectional translations at different fore-hind paw distances and to multidirectional rotations at the preferred stance distance were analyzed. Five synergies were required to adequately reconstruct responses to translation at the preferred stance distance-four were similar to our previous analysis of translation, whereas the fifth accounted for the newly added background activity during quiet stance. These five control synergies could account for > 80% total variability or r(2) > 0.6 of the electromyographic and force tuning curves for all other experimental conditions. Forces were successfully reconstructed but only when they were referenced to a coordinate system that rotated with the limb axis as stance distance changed. Finally, most of the functional muscle synergies were similar across all of the six cats in terms of muscle synergy number, synergy activation patterns, and synergy force vectors. The robustness of synergy organization across perturbation types, postures, and animals suggests that muscle synergies controlling task-variables are a general construct used by the CNS for balance control.