Khristova L G, Gidikov A A, Aslanova I F, Beliaeva M G, Kirenskaia A V
Kosm Biol Aviakosm Med. 1988 Jul-Aug;22(4):39-43.
Ten test subjects were exposed to water immersion for 3 days. Extraterritorial potentials of low and high threshold motor units (LMU and HMU) of m. biceps brachii were measured using a specially designed multielectrode and an electromyograph. The results revealed substantial changes in LMUs. A significant decrease in the propagation rate of muscle potentials was observed in 9 out of 10 test subjects. The average propagation velocity of LMU potentials was 4.93 +/- 0.16 m/s before exposure, 4.12 +/- 0.07 m/s after a day of immersion and 4.29 +/- 0.09 m/s after three days of immersion, the mean decrease being 20% and 15%, respectively. The total duration of LMU potentials increased significantly during immersion, the increase making 17.5% after a day of immersion and 13% after three days of immersion. The total depolarized zone length diminished by 1.65 mm after a day of immersion and by 1.29 mm after three days of immersion. Conversely, this exposure produced no significant changes in HMU potentials. It can be assumed that the major cause of changes in LMU potentials is reduced muscle activity.
十名受试对象接受了为期3天的水浸试验。使用专门设计的多电极和肌电图仪测量肱二头肌低阈值和高阈值运动单位（LMU和HMU）的域外电位。结果显示LMU有显著变化。在10名受试对象中，有9名观察到肌肉电位传播速率显著下降。暴露前LMU电位的平均传播速度为4.93±0.16米/秒，浸泡一天后为4.12±0.07米/秒，浸泡三天后为4.29±0.09米/秒，平均下降分别为20%和15%。浸泡期间，LMU电位的总持续时间显著增加，浸泡一天后增加17.5%，浸泡三天后增加13%。浸泡一天后总去极化区长度减少1.65毫米，浸泡三天后减少1.29毫米。相反，这种暴露对HMU电位没有显著影响。可以认为LMU电位变化的主要原因是肌肉活动减少。
