The effect of changes in the body configuration on anticipatory postural adjustments.
The effect of changes in the body configuration on anticipatory postural adjustments.
复制标题
身体形态的变化对预期姿势调整的影响。
DOI：
10.1123/mcj.7.3.264
复制
发表时间：
2003
期刊：
影响因子：
1.1
通讯作者：
Aruin,AlexanderS
中科院分区：
文献类型：
--
作者：
Aruin,AlexanderS
许多因素可能在产生预期姿势调整（APAs）的过程中起主要作用。其中包括预期扰动的大小和方向，与扰动相关的自愿动作的属性，以及姿势任务的特征，例如动作之前的身体结构。本研究的目的是分析体型对APAs的影响。对8名健康受试者进行站立时快速双侧肩部伸展运动。通过指示受试者垂直站立或上半身向前弯曲15°至60°来改变身体形态。记录体位肌的电活动和压力中心的位移。结果表明，APAs随上半身角度位置的改变而改变。腹直肌和股直肌的预期激活减少，而在前屈条件下，竖脊肌和股二头肌的预期抑制增加。结果，与垂直姿势相比，前屈的肌肉对的总预期活动仅表现出轻微的调节。这些结果表明，中枢神经系统通过补偿肌肉对中单个肌肉APAs的变化来重组体位肌肉的预期活动，从而使肌肉对的整体预期活动保持不变。这种补偿用于抵消扰动的预期机械效应，以适应体位肌肉长度的变化和由于前屈引起的身体稳定性下降。
A number of factors are likely to play a major role in the process of generation of anticipatory postural adjustments (APAs). Among them are the magnitude and direction of an expected perturbation, properties of a voluntary action associated with the perturbation, and features of the postural task such as a body's configuration prior to the action. The aim of this study was to analyze the effect of body configuration on APAs. Experiments were performed on 8 healthy subjects performing fast bilateral shoulder extension movements while standing. Body configuration was modified by instructions to the subjects to stand vertically or with a forward upper body bend varying from 15 to 60°. The electrical activity of postural muscles and displacements of the center of pressure were recorded. Results indicated that APAs were modified with changes in the angular position of the upper body. Decreased anticipatory activation was seen in rectus abdominis and rectus femoris, while increased anticipatory inhibition was observed in erecteor spinae and biceps femoris across conditions with forward bend. As a result, the total anticipatory activity of muscles in a muscle pair in series with a forward bend showed only slight modulation as compared to vertical posture. These results suggest that the CNS uses reorganization of the anticipatory activity of postural muscles by compensating for the changes in APAs of individual muscles in a muscle pair in such a way that the overall anticipatory activity of the muscle pair stays unchanged. Such compensation in counteracting the expected mechanical effects of the perturbation is used to accommodate both changes in the length of postural muscles and diminished stability of the body due to forward bend.