The effects of ergonomic intervention on the musculoskeletal complaints and fatigue experienced by workers in the traditional metal casting industry

This research aimed to evaluate the effects of ergonomic intervention on the musculoskeletal complaints and fatigue experienced by workers of the traditional metal casting industry that manually pour molten metal into molds. The workers’ physical complaints are typically in the form of musculoskeletal complaints, which include (1) an activity aspect, (2) a physical aspect, and (3) a motivational aspect. The method used in this research was stratified random sampling. The subjects (n = 127) were divided into three groups, namely, the process cement department (PCD) group, the loam department (LD) group, and the black sand department (BSD) group. The evaluation was carried out using questionnaires based on musculoskeletal complaints and fatigue. Meanwhile, an assessment of musculoskeletal complaints and fatigue was conducted one month before the ergonomic intervention, and then during follow-ups at one and eight months after the ergonomic intervention. The results showed that the average reduction in musculoskeletal complaints and fatigue experienced by the workers in the LD group was lower than that of the workers in the PCD and BSD groups at one and eight months after the ergonomic intervention. The positive effects of the ergonomic intervention on musculoskeletal complaints were evident in terms of the back, waist, left and right thighs, right knee, right ankle, and left foot (p < 0.05). The positive effects of the ergonomic intervention on the level of activity-based fatigue were felt in the body and legs, and the feeling of wanting to lie down decreased. The motivational fatigue experienced by the workers manifested as difficulty in thinking, concentrating, and controlling behavior, while the physical fatigue experienced by the workers was in the form of headaches, back pain, excessive thirst, and feeling unwell (p < 0.05). It can be concluded that ergonomic intervention can reduce both musculoskeletal complaints and fatigue, especially by conducting a morning briefing, using ergonomic ladles when pouring molten metal into molds, and consuming nutritious food during break times.