In this study, the effect of healthcare related physical and psychosocially stressful exertions on neuromuscular fatigue of the neck muscles was investigated. Eighteen healthy individuals (16 male, 2 female) performed force exertions commonly used during bed-to-stretcher patient transfer tasks under both the presence and absence of psychosocially stressful conditions. Surface electromyography (SEMG) data from two neck muscles and subjective workload ratings using the NASA Task Load Index (TLX) were collected. The SEMG data was processed and analyzed using discrete wavelet transform (DWT) to quantify development of neuromuscular fatigue. The power of the lower fatigue frequency band (12-23. Hz) was found to be significantly higher during physical exertions performed under psychosocially stressful conditions than physical exertion alone, indicating a faster fatigue development. Significantly higher NASA TLX workload scores for mental demand, temporal demand, and frustration were observed during combined physical and psychosocial exertions. The results of this study suggest that, in addition to the actual physical work, overall psychosocial stress in the work environment should be considered when designing work-rest schedules during long work shifts to reduce incidences of highly prevalent work-related neck musculoskeletal disorders among healthcare workers.
- Discrete wavelet transform