Latash M L
Department of Physical Medicine and Rehabilitation, Rush Medical College, Chicago, IL 60612.
Exp Brain Res. 1994;98(1):145-52. doi: 10.1007/BF00229119.
Predictions of three models of single-joint motor control were compared with experimental observations of the changes in electromyographic (EMG) patterns during fast voluntary movements against an unexpectedly reduced inertial load. The subjects performed elbow flexions over 40 degrees "as fast as possible" in two series. During the first series, an approximately 40% decrease in inertia, simulated by a torque-motor, might occur unpredictably on half of the trials (unloaded trials). During the second series, all the trials were unloaded. The major findings are: (1) no differences in the antagonist burst latency in unexpectedly unloaded and unperturbed trials; (2) a decrease in the antagonist latency during expected unloadings; (3) a small, statistically non significant decrease in the first agonist burst EMG integral; and (4) a larger, statistically significant increase in the antagonist burst EMG integral in unexpectedly unloaded trials as compared to unperturbed trials. The data are in good correspondence with a version of the equilibrium-point hypothesis that assumes central programming of the beginning of the antagonist burst and incorporates the possibility of reflex-induced changes in EMG amplitudes.
将三种单关节运动控制模型的预测结果与快速随意运动过程中对抗意外减小的惯性负荷时肌电图（EMG）模式变化的实验观察结果进行了比较。受试者分两组“尽可能快地”进行超过40度的肘部屈曲。在第一组中，由扭矩电机模拟的惯性大约降低40%，在一半的试验（无负荷试验）中可能会意外发生。在第二组中，所有试验均无负荷。主要发现如下：（1）意外无负荷试验和未受干扰试验中拮抗肌爆发潜伏期无差异；（2）预期无负荷时拮抗肌潜伏期缩短；（3）首次主动肌爆发EMG积分有小幅下降，但在统计学上无显著意义；（4）与未受干扰试验相比，意外无负荷试验中拮抗肌爆发EMG积分有更大幅度的增加，且在统计学上具有显著意义。这些数据与平衡点假说的一个版本高度吻合，该版本假设拮抗肌爆发开始时进行中枢编程，并考虑了反射引起的EMG振幅变化的可能性。
