Chen Jing, Ding Jia-Shun, Wang Zheng-Lun, Yang Lei
School of Public health, Tongji Medical College, Huazhong Science and Technology University, Wuhan 430030, China.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2004 Dec;22(6):402-5.
Using surface electromyography (SEMG) technique to evaluate repetitive lifting task-induced fatigue of back muscles.
Thirteen volunteers lifted and lowered an 8 kg weight from floor to waist level for 100 times. Fatigue in the erector spinae muscles was quantified by comparing the frequency content of the EMG signal during static contractions performed before, and immediately after the 100 lifts.
EMG average amplitude rose gradually during 100 lifts, the difference was significant at T10 right (P < 0.05) and L3 left (P < 0.01), the difference was not significant at T10 left and L3 right (P > 0.05). The median frequency intercept at T10 right, T10 left, L3 right, L3 left erector spinae muscles decreased by 2.0% (P > 0.05) 10.9% and 29.9% (P < 0.05), 27.9% (P < 0.01), respectively. The mean power frequency intercept decreased by 9% at L3 left erector spinae muscle (P < 0.05), the decrease was not statistically significant at other sites (P > 0.05).
Repetitive lifting may induce measurable fatigue in the erector spinae muscles. Erector spinae muscle at L3 is more easily fatigued than at T10. Using the median frequency intercept to assess muscle fatigue is more sensitive than using mean power frequency intercept.
运用表面肌电图（SEMG）技术评估重复性提举任务诱发的背部肌肉疲劳。
13名志愿者将一个8千克的重物从地面举到腰部高度，再放下，重复100次。通过比较在100次提举之前和之后立即进行的静态收缩过程中肌电信号的频率成分，对竖脊肌的疲劳进行量化。
在100次提举过程中，肌电平均幅度逐渐上升，在T10右侧（P < 0.05）和L3左侧（P < 0.01）差异显著，在T10左侧和L3右侧差异不显著（P > 0.05）。T10右侧、T10左侧、L3右侧、L3左侧竖脊肌的中位频率截距分别下降了2.0%（P > 0.05）、10.9%和29.9%（P < 0.05）、27.9%（P < 0.01）。L3左侧竖脊肌的平均功率频率截距下降了9%（P < 0.05），在其他部位下降无统计学意义（P > 0.05）。
重复性提举可能会在竖脊肌中诱发可测量的疲劳。L3处的竖脊肌比T10处的更容易疲劳。使用中位频率截距评估肌肉疲劳比使用平均功率频率截距更敏感。
