Influence of risk factors associated with musculoskeletal disorders on an inner population of northeastern Brazil

Abstract The loss of workers to musculoskeletal disorders in Brazil represents one of the main health problems in the population. However, studies on workers from the inner Brazilian regions are still scarce. Therefore, this paper aims to determine the risk factors associated with musculoskeletal symptoms of the upper, middle, and lower back of workers in the inner northeast of Brazil. Based on a cross-sectional study of 420 workers (simple random sampling method), risk factors associated with the back were identified using an ordinal logistic regression model and a structural equation model (SEM). The influence of psychosocial, biomechanical, sociodemographic, and occupational factors in the emergence of musculoskeletal disorders among workers was confirmed to exist. Biomechanical factors such as physical demands contributed directly to back symptoms. The influence of psychosocial factors was indirect and mediated by psychosocial stress. Occupational factors such as employment contract and hours worked per day, and socio-demographic factors such as age (≥45 years) had a direct influence on upper back symptoms. Working with a curved spine and with the lower limbs in an uncomfortable position have a direct influence on mid-back and lumbar symptoms, respectively. This study confirmed that the origin of WMSDs, in the three regions of the back, is multifactorial and complex. Relevance to industry: The musculoskeletal disorders have a not only a multifactorial, but also a complex origin, and risks factors may direct and indirect role in the development of symptoms. The findings are useful for better understanding and prevention of WMSD.