本研究的目的在于探讨等长负荷诱发肌肉疲劳过程中表面肌电图 (sEMG)功率谱转移的特征 ,确定反映肌肉功能水平的sEMG指标。受试者为 32名青年男性大学生志愿者。采用自身重量的竖脊肌等长运动负荷试验和肱二头肌等长负荷试验 ,记录运动肌的肌电图和负荷持续时间。实验结果表明 :(1)平均功率频率 (MPF)和中位频率 (MF)时间序列曲线均呈线性递减变化规律 ;(2 )MF、MPF时间序列曲线下降斜率值均与肌肉等长负荷持续时间有明显统计学相关。研究认为 ,MF和MPF时间序列曲线下降斜率值均是反映腰部竖脊肌功能水平的良好指标。 The purpose of this study was to investigate the characteristics of the power spectrum shift of the surface electromyogram (sEMG) during isometric load-induced muscle fatigue and to determine sEMG markers that reflect muscle function. Subjects were 32 young male college volunteers. Equal length exercise load test of erector spinae with its own weight and isometric load test of biceps were used to record the EMG and duration of exercise. The experimental results show that: (1) The time series curves of average power frequency (MPF) and median frequency (MF) decrease linearly; (2) The descending slope values ​​of MF and MPF time series curves are similar to those of muscle length load duration There is a statistically significant correlation. The study suggests that the slope values ​​of MF and MPF time series curves are good indicators of functional level of lumbar spine muscle.