肢体肌肉运动单位电位时限与波幅间关系的研究

Correlation between MUPs duration and amplitude in limb muscle

目的:研究肢体肌肉正常运动单位电位时限与波幅间的关系。方法:记录165名不同性别、年龄受试者的肱二头肌、拇短展肌、股四头肌内侧头、胫骨前肌共392块肌肉的运动单位电位,运用统计学的方法分析时限与波幅间的关系。结果:运动单位电位时限与波幅相关系数为0.54,时限-波幅曲线类似于横"S"型;约在9.6～11.5 ms时限范围内较为平缓,误差棒也较小;此范围外波幅误差棒明显增大;在9.6～11.5 ms时限范围内4个部位肌肉、性别和年龄间的波幅时限比值没有统计学差异(P=0.44,P=0.21,P=0.22)。结论:波幅与时限间成明显相关性且可能和肌群、性别、年龄无关,是骨骼肌运动单位较稳定的电学特性。超出一定时限范围波幅的变异性明显变大。

Objective：To study the correlation between duration and amplitude of motor unit potentials（MUPs） in limb muscle.Methods：MUPs were recorded in 392 blocks of muscles including biceps brachii,abductor pollicis brevis,quadriceps femoris and tibialis anterior in 165 subjects who were different in gender and age.The correlation between duration and amplitude were analyzed by statistical methods.Results：The correlation coefficient between duration and amplitude was 0.54.The duration-amplitude curve was like transverse S type;and it was gentler and had less error bars in duration of 9.6ms to 11.5 ms.The error bars of amplitude enlarged remarkably beyond the area.The amplitude-duration ratios of different muscles,genders and ages in duration of 9.6ms to 11.5ms had no significant deviation（P=0.44,P=0.21,P=0.22）.Conclusion：There is obvious correlation between amplitude and duration but may be irrelative to the musculature,gender and age.This is a stable electrical characteristic of skeletal muscle motor unit.The variability of amplitude rises apparently when beyond a certain duration range.