Basic postures and risk factors for occupational low back pain: an investigation with workers and health professionals

Abstract

Introduction: The association between postures at work and LBP in workers has conflicting results. There is no comparison between the different postures, as well as there is a lack of information between exposure time in these occupational postures
and the presence of LBP. In addition, few LBP risk factors are controlled in the studies performed. Finally, there are no reports in the literature on the knowledge of occupational health professionals regarding the LBP risk factors. The present thesis verified the relationship between basic postures and risk factors for occupational LBP in four different investigations. Objectives: The first study analyzed the relationship between work-related lumbar posture (sitting, standing, walking, alternating posture) and LBP in workers. The second investigation developed and validated a cutoff point for daily postures to discriminate workers with LBP. The third study analyzed the prevalence and the factors associated with musculoskeletal complaints in nursing professionals. Finally, the last investigation verified the knowledge about LBP risk factors, beliefs and attitudes about LBP management among health professionals working in the occupational area. Methods: The first and second studies analyzed 529 records of adult workers from a private company database. Predominant work-related lumbar posture was classified based on time spent in each posture. LBP symptoms in the last 12 months and during the last 7 days were the study outcomes. The multivariate analysis model evaluated the independent relationship between occupational posture and 22 personal, occupational, clinical and psychosocial covariates with LBP. Receiver operating characteristics curve (ROC curve) verified the ability of daily time in each posture in discriminating workers with low back pain in a training sample. The third study was composed of 61 records of female nursing workers. Twelve personal, occupational, clinical, and psychosocial covariates were evaluated. The multivariate analysis model evaluated the independent relationship between potential exposure factors and musculoskeletal complaints. The last study recruited 81 Brazilian workers' health professionals who answered an electronic questionnaire about knowledge, beliefs and attitudes about LBP. Results: The
adjusted logistic regression model indicated that predominant walking reduced the likelihood to report LBP during the last 12 months when compared to standing (OR=0.54; 95%CI 0.30, 0.99; p=0.048), but there is no association between work related postures and recent LBP. Adjusted analyzes also revealed an association between LBP and female sex, pain in another body region, and previous LBP. The daily time spent in a given posture was not able to accurately discriminate against workers with LBP. Total time spent walking was the only daily posture that discriminated workers with LBP in the last year in the testing sample, albeit with low
accuracy. A high prevalence of musculoskeletal complaints (86.9%) was found among nursing professionals, with the lumbar region, shoulder, upper back and neck being the most affected parts. An association was found between musculoskeletal neck complaints and no breaks at work, shoulder complaints and overweight or obesity, wrists/hands complaints and workday > 8 hours, upper back complaints and feeling of frequent tiredness, and between hips/thigs complaints and mental stress. Finally, obesity (7.4%), sitting for more than 2 hours (8.6%), physical activity (9.9%), lack of psychosocial support at work (11.1 %) and daily alcohol consumption (37.0%) had the lowest rates of knowledge by professionals about LBP risk factors. In addition, factors about general health showed the highest lack of knowledge. Conclusions: Standing posture increases the likelihood to report LBP last year when compared to walking. An episode of LBP is associated with personal and clinical factors for both recent cases and previous year. The daily time spent in a given posture was not able to accurately distinguish workers with LBP. A high prevalence of musculoskeletal complaints in
nursing professionals was evidenced, as well as personal, occupational, clinical and psychosocial characteristics were associated with musculoskeletal complaints in the last 12 months among these professionals. Finally, Brazilian occupational health professionals lack knowledge about non-occupational LBP risk factors, especially general health status.