Risk factors for work-related musculoskeletal disorders among workers in Brazil: A structural equation model approach

Abstract

This study aimed to verify the direct and indirect influence of risk factors on the symptoms of WMSDs in the thigh, leg, and foot among workers in the inner regions of Brazil. Research tested a structural equation model (SEM) that describes hypothetical relationships between risk factors and WMSDs. Questionnaires were used to collect data on sociodemographic, occupational, biomechanical, and psychosocial factors, and pain symptoms about 420 workers. The results showed that different factors directly affect the thigh, leg, and foot. Maintaining the lower limbs in uncomfortable positions increases the chances of developing WMSDs in the thigh (β = 0.219; p-value <0.001), leg (β = 0.223; p-value <0.001), and foot (β = 0.158; p-value <0.01). Most psychosocial factors attenuate psychosocial stress, which in turn directly alleviates WMSD symptoms in the thigh (β = −0.502; p-value <0.001), leg (β = −0.315; p-value <0.01), and foot (β = −0.246; p-value <0.01). Factors were also found to uniquely affect aspects such as “another job” (β = −0.246; p-value <0.01) in the leg and effort (β = 0.146; p-value <0.05) in the foot. It was concluded that multiple factors influence the development of WMSDs in the lower limbs. These findings contribute to the existing knowledge on the causes of WMSDs and can help improve working conditions for the population under study. Therefore, managers and health, ergonomics, and occupational safety professionals can use the findings to develop more precise strategies to reduce the impacts of WMSDs on workers.