Postural adjustments associated with rapid voluntary arm movements. II. Biomechanical analysis.
Postural adjustments associated with rapid voluntary arm movements. II. Biomechanical analysis.
复制标题
与快速自愿手臂运动相关的姿势调整。
DOI：
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发表时间：
1988
影响因子：
11
通讯作者：
S R Simon
中科院分区：
文献类型：
--
作者：
W. G. Friedli;L. Cohen;M. Hallett;S. Stanhope;S R Simon
正常受试者在站立时进行双侧对称的快速肘关节屈曲或伸展（“焦点运动”）。在每种类型的运动中，腿部和躯干肌肉的肌电活动（“相关姿势调整”）都有特定的模式。这些姿势调整的生物力学意义进行了分析，通过地面反作用力和运动的各个身体部分。实验数据与理论模型的机构组成的六段动力链与刚性链接。屈肘时地面反作用力的模式与伸肘时相反。身体各节段的运动都很小，并且特定于某个焦点运动。动态扰动所产生的手臂运动在一个前后方向被认为是补偿姿势调整，而垂直扰动没有得到补偿。在不同的运动中，不同关节的肌肉活动与补偿焦点运动引起的净关节反应力矩所需的活动预测相关。身体各部分的运动可以理解为不同关节处的净反作用力矩和净肌肉力矩的相互作用。动态姿势要求是通过在焦点移动之前启动的精确主动补偿来实现的。
Normal subjects performed bilaterally symmetric rapid elbow flexions or extensions ("focal movements") while standing. Specific patterns of electromyographic activity in leg and trunk muscles ("associated postural adjustments") were seen for each type of movement. The biomechanical significance of these postural adjustments was analysed by means of the ground reaction forces and motion of the various body segments. Experimental data were compared with that from a theoretical model of the body consisting of a six segment kinetic chain with rigid links. Distinct patterns of the ground reaction forces with elbow flexion were opposite in direction to those seen with elbow extension. Movements of the various body segments were small and specific for a certain focal movement. Dynamic perturbations arising from the arm movement in an anteroposterior direction were found to be compensated by postural adjustments, whereas vertical perturbations were not compensated. The muscular activity acting about different joints in the different movements was found to correlate with the predictions of activity needed to compensate for net joint reaction moments arising from the focal movement. Motion of the various body segments could be understood as resulting from the interplay of the net reaction moments and the net muscular moments at the different joints. Dynamic postural requirements are accomplished by a precise active compensation initiated before the focal movement.