Renda Erika, Liu Ruoyan, Côté Julie N
Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada.
Occupational Biomechanics and Ergonomics Laboratory, Michael Feil and Ted Oberfeld/CRIR Research Centre, Jewish Rehabilitation Hospital, Laval, Quebec, Canada.
IISE Trans Occup Ergon Hum Factors. 2025 Jun 18:1-13. doi: 10.1080/24725838.2025.2517026.
Occupational ApplicationsIn this study, healthy adults performed repetitive bilateral overhead shoulder flexion to fatigue-failure while we measured electromyography of shoulder muscles. We found that ambidextrous and right-handed individuals, especially females, exhibit asymmetrical muscle activation patterns during the task. To enhance worker health and safety, handedness and sex should be considered when implementing workplace changes. For instance, our results may imply that job rotation strategies that alternate use of hands would be easier to implement for males. Moreover, to minimize risk of injury, bilateral asymmetry in muscle activity could be monitored using wearable technology. In our experiment, the mean time to fatigue-failure was under 5 min, which was enough to elicit asymmetry of muscle activation. Therefore, we recommend frequent breaks after a few minutes of work when feasible, in order to avoid asymmetrical loadings during bilateral manual work, especially among females, who both have higher injury risk and more bilateral asymmetry.
职业应用
在本研究中，健康成年人进行重复性双侧过头肩部屈曲直至疲劳衰竭，同时我们测量了肩部肌肉的肌电图。我们发现，双手灵巧者和右利手个体，尤其是女性，在任务过程中表现出不对称的肌肉激活模式。为了提高工人的健康和安全水平，在实施工作场所变更时应考虑用手习惯和性别因素。例如，我们的结果可能意味着，交替使用双手的工作轮换策略对男性来说更容易实施。此外，为了将受伤风险降至最低，可以使用可穿戴技术监测肌肉活动的双侧不对称情况。在我们的实验中，疲劳衰竭的平均时间不到5分钟，这足以引发肌肉激活的不对称性。因此，我们建议在可行的情况下，工作几分钟后频繁休息，以避免双侧体力劳动期间的不对称负荷，尤其是在女性中，她们受伤风险更高且双侧不对称情况更多。
