Tanii K
Human-Environment System Department, National Institute of Bioscience and Human-Technology, Ibaraki, Japan.
Electromyogr Clin Neurophysiol. 1996 Mar;36(2):99-105.
The present study was performed to investigate whether modes of voluntary contraction have an influence on an appearance of the premovement silent period (PSP) and components of the premovement cortical potentials. The EMG and the EEG were simultaneously recorded in an isometric ballistic contraction for exerting rapidly an elbow extension force and in a ballistic contraction for fast extending an elbow joint. The prime mover in the 2 contraction modes was the triceps brachii muscle. The frequency of the PSP was significantly higher in the isometric ballistic contraction than in the ballistic contraction (P < 0.01). The duration of the PSP was significantly longer in the isometric ballistic contraction than in the ballistic contraction (P < 0.01). In the isometric ballistic contraction, the 3 premovement cortical potentials (FNP, SNP and TNP) were identified. However, in the ballistic contraction the TNP did not appear. The PSP occurred in the phase of the TNP. The results obtained suggest that the PSP and the TNP are related to a more forceful contraction with faster rates of contraction, rather than only to speed of muscular contraction.
本研究旨在探讨自主收缩模式是否会对运动前静息期（PSP）的表现及运动前皮层电位的成分产生影响。在等长弹道收缩（快速施加伸肘力）和弹道收缩（快速伸展肘关节）过程中，同时记录肌电图（EMG）和脑电图（EEG）。两种收缩模式中的原动肌均为肱三头肌。等长弹道收缩时PSP的频率显著高于弹道收缩（P < 0.01）。等长弹道收缩时PSP的持续时间显著长于弹道收缩（P < 0.01）。在等长弹道收缩中，识别出了3种运动前皮层电位（FNP、SNP和TNP）。然而，在弹道收缩中TNP未出现。PSP出现在TNP阶段。所得结果表明，PSP和TNP与更有力且收缩速率更快的收缩有关，而非仅与肌肉收缩速度有关。
