Javed Iqra, Nukman Yusoff, Ghazilla Raja Ariffin Bin Raja, Ahmad Ashfaq, Dawal Siti Zawiah Md, Tayyab Aisha, Rashid Zahid
Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia.
School of Systems and Technology, University of Management and Technology, Lahore, Pakistan.
BMC Musculoskelet Disord. 2024 Oct 1;25(1):757. doi: 10.1186/s12891-024-07874-4.
Workers are driven to work faster in the industrial work environment to meet high productivity targets. An increased work pace leads to increased muscle activation. However, the effect of work pace on bilateral upper trapezius muscles during sewing machine operation in an industrial work environment has not been thoroughly investigated in experimental studies. Therefore, this research aims to conduct an experimental study to analyze the bilateral upper trapezius muscle activity of industrial sewing machine operators at different levels of work pace. Thirty subjects (15 males, and 15 females) continuously performed the sewing operation for two hours in an industrial work environment. Experiments were conducted for two levels of work pace i.e. low pace (100% of standard cycle time) and high pace (120% of standard cycle time). Electromyographic signals were recorded from the bilateral upper trapezius muscles. The EMG amplitude (RMS) among the muscles was computed. A statistically significant (p < 0.05) increase in muscle activity was observed with an increased work pace. In this study, right upper trapezius muscle activity increased by 30.4% during high work pace tasks compared to low pace, while the left upper trapezius showed a 24.12% increase. The right upper trapezius showed a mean difference of 0.696 (%MVC), and the left upper trapezius showed 0.399 (%MVC), both indicating greater activity during high-pace tasks. The increase in muscle activity with time indicated the presence of muscle fatigue among sewing machine operators. Furthermore, higher muscular activity was observed among females than males. This research highlights the critical need to balance productivity goals with the health and safety of workers, reducing the risk of muscle fatigue and associated work-related musculoskeletal disorders.
在工业工作环境中，工人们被迫加快工作速度以实现高生产率目标。工作节奏加快会导致肌肉激活增加。然而，在工业工作环境中操作缝纫机时，工作节奏对双侧上斜方肌的影响在实验研究中尚未得到充分调查。因此，本研究旨在进行一项实验研究，以分析不同工作节奏水平下工业缝纫机操作员双侧上斜方肌的活动情况。30名受试者（15名男性和15名女性）在工业工作环境中连续进行了两小时的缝纫操作。针对两种工作节奏水平进行了实验，即低节奏（标准周期时间的100%）和高节奏（标准周期时间的120%）。记录双侧上斜方肌的肌电信号。计算肌肉间的肌电幅度（均方根值）。随着工作节奏加快，观察到肌肉活动有统计学意义的显著增加（p < 0.05）。在本研究中，与低节奏相比，高工作节奏任务期间右上斜方肌的肌肉活动增加了30.4%，而左上斜方肌增加了24.12%。右上斜方肌的平均差异为0.696（%MVC），左上斜方肌为0.399（%MVC），两者均表明在高节奏任务期间活动更强。肌肉活动随时间的增加表明缝纫机操作员存在肌肉疲劳。此外，观察到女性的肌肉活动高于男性。本研究强调了在提高生产率目标与工人健康和安全之间取得平衡的迫切需要，以降低肌肉疲劳和相关工作性肌肉骨骼疾病的风险。
