Ding Jia-Shun, Wang Zheng-Lun, Zhang Hai-Yang, Yang Lei
School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2004 Dec;22(6):406-9.
To evaluate the intramuscular loads of the upper limb during static postures and repetitive work by surface electromyography.
Twenty-six male college student volunteers were recruited for the experiment. The surface electromyography (SEMG) singal were recorded from the brachioradialis, biceps brachii, deltoid and trapezius of right arm during static postures including forward elevating, abducting, extending and a repetitive performance at different height of the bench, and root mean square (RMS) values were educed from the singal.
The SEMG amplitudes from forward elevating and abducting were in direct proportion to the angle of the elevating and abducting (r > 0.9, P < 0.01). The maximal voluntary electrical activation (MVE) of the deltoid were 6.4%, 10.1%, 12.6%, 16.2% and 20.8% while the arm elevated forward at an angle of 0 degrees , 45 degrees , 90 degrees , 135 degrees and 180 degrees respectively. The repetitive work showed that the height of the bench and the duration had more effects on deltoid and trapezius than the other muscles. The MVE% of the deltoid were 13.0%, 14.4% and 15.6% while the bench was 74, 79 and 84 cm in height respectively (P < 0.01).
SEMG which is suitable for determining and reflecting the muscle strain during static postures and repetitive work may be a reasonable indicator for the assessment of manual workload and the ergonomic design.
通过表面肌电图评估静态姿势和重复性工作期间上肢的肌肉负荷。
招募26名男性大学生志愿者参与实验。在包括前举、外展、伸展等静态姿势以及在不同高度长凳上的重复性动作过程中，记录右臂肱桡肌、肱二头肌、三角肌和斜方肌的表面肌电图（SEMG）信号，并从信号中得出均方根（RMS）值。
前举和外展时的SEMG幅度与举升和外展角度成正比（r>0.9，P<0.01）。当手臂分别以0度、45度、90度、135度和180度前举时，三角肌的最大自主电激活（MVE）分别为6.4%、10.1%、12.6%、16.2%和20.8%。重复性工作表明，长凳高度和持续时间对三角肌和斜方肌的影响比对其他肌肉的影响更大。当长凳高度分别为74、79和84厘米时，三角肌的MVE%分别为13.0%、14.4%和15.6%（P<0.01）。
适用于确定和反映静态姿势和重复性工作期间肌肉应变的表面肌电图可能是评估体力劳动负荷和人体工程学设计的合理指标。
