Aruin A S, Latash M L
Department of Kinesiology, Pennsylvania State University, University Park 16802, USA.
Electroencephalogr Clin Neurophysiol. 1996 Dec;101(6):497-503. doi: 10.1016/s0013-4694(96)95219-4.
The purpose of the study was to define whether anticipatory postural adjustments scale with the magnitude of a self-triggered postural perturbation when a standard motor action triggers the perturbation. Standing subjects generated vertical forces of different magnitude with their extended arms against a bar connected through a rigid cord to the floor. They released the bar with a standard bilateral shoulder abduction. Anticipatory postural adjustments were seen as changes in the level and/or timing of the background activation of postural muscles. Muscles of the dorsal part of the legs and of the trunk demonstrated an anticipatory decrease in the level of activation, commonly leading to its complete disappearance. There was no relation between the magnitude of the unloading and the timing of the changes in the background activity of these muscles. Muscles of the frontal part of the legs and of the trunk demonstrated an anticipatory increase in their activity whose timing and amplitude correlated positively with the magnitude of the perturbation. We conclude that anticipatory postural adjustments can be scaled with respect to the magnitude of a self-triggered perturbation.
本研究的目的是确定当标准运动动作引发扰动时，预期姿势调整是否会随着自我引发姿势扰动的幅度而变化。站立的受试者用伸直的手臂对通过刚性绳索连接到地面的横杆施加不同大小的垂直力。他们通过标准的双侧肩部外展动作松开横杆。预期姿势调整被视为姿势肌肉背景激活水平和/或时间的变化。腿部和躯干背部的肌肉表现出激活水平的预期下降，通常导致其完全消失。卸载幅度与这些肌肉背景活动变化的时间之间没有关系。腿部和躯干前部的肌肉表现出其活动的预期增加，其时间和幅度与扰动幅度呈正相关。我们得出结论，预期姿势调整可以根据自我引发扰动的幅度进行调整。
