TRI-DIMENSIONAL AND TRIPHASIC MUSCLE ORGANIZATION OF WHOLE-BODY POINTING MOVEMENTS
TRI-DIMENSIONAL AND TRIPHASIC MUSCLE ORGANIZATION OF WHOLE-BODY POINTING MOVEMENTS
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DOI：
10.1016/j.neuroscience.2010.07.006
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发表时间：
2010-11-10
期刊：
影响因子：
3.3
通讯作者：
Pozzo, T.
中科院分区：
文献类型：
--
作者：
Chiovetto, E.;Berret, B.;Pozzo, T.
先前的运动学和动力学研究表明，当完成超过手臂长度的全身指向任务时，模块化和灵活的组织可以代表同时控制目标指向和平衡维持的鲁棒解决方案。在这里，我们研究了产生这种协调运动结构的潜在机制。我们监测了受试者在手臂长度以外进行指指动作时的大量肌肉活动，无论是否施加姿势或指指限制。分析表明，肌肉信号位于三维超平面上，并在时间上按照三相模式组织（三个组成部分，每个组成部分表现出单个激活峰，并且峰值在时间上是连续的）。这种功能性肌肉协同作用被发现在各种条件下都是强大的。此外，在每个身体关节处单独的肌肉群的活动也产生了三维的效果。特别是那些与下半身关节肌肉（脚踝、膝盖和臀部）相关的肌肉在所有条件下都呈现这三种顺序。然而，上肢肌肉活动的组织结构略有不同，这表明这些肌肉的活动对运动限制具有中等程度的灵活性。在运动控制的层次视图中，目前的研究结果将整个身体指向运动的关节协调与基本的肌肉协同组织（即三相模式）联系在一起。(c) 2010 ibro。Elsevier Ltd.出版。版权所有。
Previous kinematic and kinetic studies revealed that, when accomplishing a whole-body pointing task beyond arm's length, a modular and flexible organization could represent a robust solution to control simultaneously target pointing and equilibrium maintenance. Here, we investigated the underlying mechanisms that produce such a coordinative kinematic structure. We monitored the activity of a large number of muscles spread throughout subjects' bodies while they performed pointing movements beyond arm's length, either with or without imposition of postural or pointing constraints. Analyses revealed that muscle signals lied on a tri-dimensional hyper-plane and were temporally organized according to a triphasic pattern (three components, each one exhibiting one single peak of activation and the peaks being consecutive in time). Such a functional muscle synergy was found to be robust across conditions. Also the activities of the separate groups of muscles acting at each body joint resulted tri-dimensional. In particular, those associated with the muscles of the lower-body joints (ankle, knee and hip) always presented the three sequences in all conditions. However, a slightly different organization was found for the muscle activities of the upper-limb, suggesting a moderate level of flexibility of the activity of such muscles to movement constraints. The present findings link together, in a hierarchical view of motor control, the joint coordination characterizing whole-body pointing movements with a basic muscle synergistic organization, namely a triphasic pattern. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.