Risk of neck musculoskeletal disorders among males and females in lifting exertions

Abstract

Work-related neck disorders are common among various occupational groups. Despite clear epidemiological evidence for the association of these disorders with forceful arm exertions, the effect of such exertions on the biomechanical behavior of the neck muscles is currently not well understood. In this study, the effect of lifting tasks on the biomechanical loading of neck muscles was investigated for males and females. Twenty-six participants (13 males and 13 females) performed bi-manual isometric lifting tasks at knuckle, elbow, shoulder, and overhead heights by exerting 25%, 50%, and 75% of their maximum strength. The activity of the cervical trapezius and sternocleidomastoid muscles was recorded bilaterally using surface electromyography. Higher activity of the cervical trapezius muscle (10% MVC–43% MVC) compared to the sternocleidomastoid muscle (4% MVC–18% MVC) was observed. Females tend to use the sternocleidomastoid muscle to a greater extent than males, whereas, higher cervical trapezius muscle activation was observed for males than females. The main effect of weight and height, and weight by height interaction on the activity of neck muscles was statistically significant (all p < 0.001). The results of this study demonstrate that the neck muscles play an active role during lifting activities and may influence development of musculoskeletal disorders due to resulting physiological changes. Relevance to industryLifting and forceful arm exertions are common at workplaces. The effect of lifting tasks on the biomechanical loading of neck muscles was evaluated in this study. Understanding this effect would improve our pathophysiological understanding of neck WMSDs caused by physically demanding exertions. This will further facilitate development of workplace intervention to modify workplace methods and/or designs so that incidences of neck WMSDs caused by lifting and forceful arm exertions could be minimized.