CENTRAL PROGRAMMING OF POSTURAL MOVEMENTS - ADAPTATION TO ALTERED SUPPORT-SURFACE CONFIGURATIONS
CENTRAL PROGRAMMING OF POSTURAL MOVEMENTS - ADAPTATION TO ALTERED SUPPORT-SURFACE CONFIGURATIONS
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DOI：
10.1152/jn.1986.55.6.1369
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发表时间：
1986-06-01
影响因子：
2.5
通讯作者：
NASHNER, LM
中科院分区：
文献类型：
--
作者：
HORAK, FB;NASHNER, LM
我们研究了在何种程度上自动姿势动作站立的人类受试者组织的有限的剧目的中央电机程序。受试者站在不同长度的支撑表面上，这迫使他们采取不同的姿势运动策略来补偿相同的外部扰动。我们评估了是否连续或有限的一组肌肉激活模式被用来产生不同的运动模式和运动模式的程度受先前的经验。暴露受试者站在一个正常的支持表面简短的向前和向后的水平表面扰动引起相对刻板的模式的腿和躯干肌肉激活与73- 110-ms的lavelet。活动开始于踝关节肌肉，然后依次辐射到大腿，然后是身体同一背侧或腹侧的躯干肌肉。这种激活模式对踝关节施加了补偿扭矩，通过向前或向后移动身体重心来恢复平衡。这种模式被称为踝关节策略，因为它主要通过围绕踝关节移动身体来恢复平衡。为了成功地保持平衡，而站在一个支持表面短的脚的长度，科目激活腿部和躯干肌肉在类似的lavelance，但组织的活动不同。躯干和大腿肌肉拮抗踝关节策略中使用的被激活的相反的近端到远端的顺序，而踝关节肌肉一般反应迟钝。这种激活模式产生了对支撑表面的补偿性水平剪切力，但几乎没有踝关节扭矩。这种模式被称为髋关节策略，因为产生的运动主要集中在髋关节上。暴露受试者的水平表面扰动，而站在中间的长度之间的最短和最长的支撑表面引起更复杂的姿势运动和相关的肌肉激活模式，类似于踝关节和髋关节的策略结合在不同的时间关系。这些复杂的姿势运动是通过扭矩和水平剪切力以及踝关节和髋关节的运动来执行的。在从一个支撑表面长度改变到另一个支撑表面长度之后的前5-20个实践试验期间，响应延迟没有改变。然而，激活模式是复杂的，类似于在中间长度的表面上良好实践的立场期间观察到的模式。（400字处截断摘要）
We studied the extent to which automatic postural actions in standing human subjects are organized by a limited repertoire of central motor programs. Subjects stood on support surfaces of various lengths, which forced them to adopt different postural movement strategies to compensate for the same external perturbations. We assessed whether a continuum or a limited set of muscle activation patterns was used to produce different movement patterns and the extent to which movement patterns were influenced by prior experience. Exposing subjects standing on a normal support surface to brief forward and backward horizontal surface perturbations elicited relatively stereotyped patterns of leg and trunk muscle activation with 73- to 110-ms latencies. Activity began in the ankle joint muscles and then radiated in sequence to thigh and then trunk muscles on the same dorsal or ventral aspect of the body. This activation pattern exerted compensatory torques about the ankle joints, which restored equilibrium by moving the body center of mass forward or backward. This pattern has been termed the ankle strategy because it restores equilibrium by moving the body primarily around the ankle joints. To successfully maintain balance while standing on a support surface short in relation to foot length, subjects activated leg and trunk muscles at similar latencies but organized the activity differently. The trunk and thigh muscles antagonistic to those used in the ankle strategy were activated in the opposite proximal-to-distal sequence, whereas the ankle muscles were generally unresponsive. This activation pattern produced a compensatory horizontal shear force against the support surface but little, if any, ankle torque. This pattern has been termed the hip strategy, because the resulting motion is focused primarily about the hip joints. Exposing subjects to horizontal surface perturbations while standing on support surfaces intermediate in length between the shortest and longest elicited more complex postural movements and associated muscle activation patterns that resembled ankle and hip strategies combined in different temporal relations. These complex postural movements were executed with combinations of torque and horizontal shear forces and motions of ankle and hip joints. During the first 5-20 practice trials immediately following changes from one support surface length to another, response latencies were unchanged. The activation patterns, however, were complex and resembled the patterns observed during well-practiced stance on surfaces of intermediate lengths.(ABSTRACT TRUNCATED AT 400 WORDS)