Pailhous J, Bonnard M, Coyle T
UMR movement et perception, CNRS, université de la Méditerranée, Faculté des sciences du sport, Marseille, France.
C R Acad Sci III. 1996 Sep;319(9):773-7.
In biological systems, obviously dissipative, some injection of muscle force is required in order to sustain rhythmic movement. As the movement frequency increases, the way the muscle-force-to-movement relationship evolves (in timing and amplitude) can be used to characterize some fundamental control properties, including whether the observed system is autonomous or forced. In the case of a simple rhythmic, biological movement (single-joint horizontal forearm movement), this question can be addressed by assuming that the processed electromyographic activity (EMG) is related to the muscle torques. In this case, 2 interesting phenomena can be observed as the frequency increases. The first is that the phase lag between the force and movement remains constant (40 degrees), and the second is that the co-contraction of the agonist and antagonist muscle groups increases with the square of the frequency. These results showed that the contribution of muscle forces to movement organization cannot be regarded in terms of an escapement in an autonomous system, nor in terms of a forcing function in a forced system.
在明显具有耗散性的生物系统中，为了维持有节奏的运动，需要注入一定的肌肉力量。随着运动频率的增加，肌肉力量与运动之间关系的演变方式（在时间和幅度上）可用于表征一些基本的控制特性，包括所观察的系统是自主的还是受迫的。对于简单的有节奏的生物运动（单关节水平前臂运动），这个问题可以通过假设处理后的肌电图活动（EMG）与肌肉扭矩相关来解决。在这种情况下，随着频率增加，可以观察到两个有趣的现象。第一个现象是力与运动之间的相位滞后保持恒定（40度），第二个现象是主动肌和拮抗肌组的共同收缩随频率的平方增加。这些结果表明，肌肉力量对运动组织的贡献既不能被视为自主系统中的擒纵机构，也不能被视为受迫系统中的强迫函数。
