刮研工不同脊柱前倾角度竖脊肌表面肌电特征研究

Study on surface electromyography characteristics of erector spinae muscles at different spinal anteversion angles of the scrapers

目的模拟并评价不同脊柱前倾角度工人的刮研工作,探究不同前倾角度对刮研工竖脊肌的影响。方法于2019年11月,募集16名男性在校大学生志愿者,模拟工人刮研工作,参数分别为25°、15次/min,15°、30次/min,5°、60次/min。采用表面肌电仪收集试验者竖脊肌肌电信号,并结合Borg量表进行竖脊肌表面肌电特征评价。结果三组不同脊柱前倾角度下,试验者左右侧竖脊肌最大随意收缩百分比(MVE%)组间差异均有统计学意义(F_(左)=13.41,P左<0.001;F_(右)=4.74,P右=0.005),且在25°、15次/min时较高。在15°、30次/min时,试验者左侧MVE%值明显高于右侧(t=2.58,P=0.021)。三组右侧竖脊肌肌电的平均功率频率(MPF)差异有统计学意义(F=9.42,P<0.001),而左侧竖脊肌肌电的MPF值差异无统计学意义(F=0.30,P=0.823);拟合直线显示,左侧竖脊肌MPF值在5°、60次/min时呈下降趋势(t=-5.39,P=0.012)。结论刮研工在姿势为15°、30次/min时产生疲劳的可能性较低,而在5°、60次/min时工作更易产生疲劳。

Objective To simulate and evaluate the scraping and grinding work of workers with different spinal anteversion angles,and to explore the effects of different anteversion angles on the erector spinae muscles of scrapers.Methods In November 2019,16 male college student volunteers were recruited to simulate workers'scraping and grinding work.The parameters were 25°,15 times/min,15°,30 times/min,5°,60 times/min respectively.The surface electromyography(sEMG)was used to collect the electromyographic signals of the erector spinae muscles,and the surface electromyographic characteristics of the erector spinae muscles were evaluated with Borg Scale.Results There were significant differences between the maximum voluntary contraction percentage(MVE%)of the left and right erector spinae muscles groups in the three groups with different spinal anteversion angles(F_(left)=13.41,Pleft<0.001;F_(right)=4.74,Pright=0.005),and the EMG amplitude was higher at 25°,15 times/min.At 15°,30 times/min,MVE%of the left side was significantly higher than that of the right side(t=2.58,P=0.021).There was significant difference in the mean power frequency(MPF)of the right erector spinae muscle in the three groups(F=9.42,P<0.001),but there was no significant difference in the MPF of the left erector spinae muscle(F=0.30,P=0.823).The fitting line showed that the left erector spinae muscle showed a downward trend at 5°,60 times/min(t=-5.39,P=0.012).Conclusion Scrapers are less likely to be fatigued when the posture is 15°,30 times/min,but they are more likely to be fatigued when working at 5°,60 times/min.