Effects of inertial load and velocity on the braking process of voluntary limb movements
Effects of inertial load and velocity on the braking process of voluntary limb movements
复制标题
惯性载荷和速度对肢体随意运动制动过程的影响
DOI：
10.1007/bf00236760
复制
发表时间：
1979
影响因子：
2
通讯作者：
F. Lestienne
中科院分区：
文献类型：
--
作者：
F. Lestienne
摘要本研究的目的是确定人类在不同速度和幅度以及不同惯性负载下进行的自愿前臂运动的制动过程。用于估计制动过程参数的程序涉及运动的运动学分析以及通过记录肌电图（EMG）活动来测量屈肌和伸肌的α运动输入。我们已经证明，当主动力不超过伸肌和屈肌产生的被动粘弹性张力时，运动可以仅由粘弹性力制动。相反，超过这个力阈值，发现主动肌和拮抗肌的运动输出由明确的肌电图活动爆发组成，首先是主动肌，然后是拮抗肌。这两次爆发的时间（激动剂活动的持续时间和拮抗剂活动的开始）与峰值速度的值明显相关。对于相同的峰值速度，增加惯性负载会增加主动肌和拮抗肌的兴奋水平，但不会改变肌电图爆发的时间。对这些结果的讨论集中在“运动单位”的概念上，该概念旨在减少作用于同一关节的肌肉的大量可能的激活模式。
SummaryThe aim of this study has been to identify, in humans, the braking process underlying voluntary forearm movements performed at various velocities and amplitudes and against different inertial loads. The procedure used to estimate the parameters of the braking process involved kinematic analysis of the movement and measurement of alpha-motoneural input to flexor and extensor muscles by recording electromyographic (EMG) activity. We have shown that when the agonist force does not exceed the passive viscoelastic tension developed by the extensor and flexor muscles, the movement can be braked by the viscoelastic forces alone. In contrast, above this force threshold, it was found that the motor output in agonist and antagonist muscles consists of well defined bursts of EMG activity, first in agonist then in antagonist muscles. The timing of these two bursts (duration of the agonist activity and onset of the antagonist activity) are clearly correlated with the value of the peak velocity. For the same peak velocity, the addition of inertial loads increases the excitation level of both agonist and antagonist muscles but does not change the timing of the EMG bursts. The discussion of these results focuses on the concept of “unit of movement” organized to reduce the large number of possible patterns of activation of the muscles acting on the same joint.