Assessment of risk factors of upper-limb musculoskeletal disorders in a fish processing industry

Abstract

A large number of studies show that awkward postures and repetitive hand and wrist movements contribute to the development of work-related musculoskeletal disorders (WMSDs). To effectively prevent these problems, there is a need for precise and quantitative knowledge about the relation between exposure and effect. In most epidemiological studies of disorders of the upper limbs, information about exposure is too limited or imprecise. Moreover, the exposure often involves several dimensions, and therefore it is necessary to use reliable methods to obtain trustworthy risk estimates. Therefore, the aim of this study was to evaluate the risks in relation to repetitive movements of the upper limbs of workers, as well as analyze the effects of a reduced work pace on the risk levels in a fish processing industry. The study was conducted in a Brazilian fish processing industry with 1,900 workers, who were divided into two work shifts. The OCRA checklist was used to assess 10% of the total workforce during work tasks. The 13 main work tasks (homogeneous groups) of the productive sector were analyzed. The occupational repetitive actions performed by workers were 81.5 ± 19.2 per minute, representing 10 points on the OCRA scale (0 to 10 point scale). The average score of the OCRA checklist was 18.4 ± 2.9 (moderate risk). Considering the five risk categories proposed by the OCRA method, 12 tasks were deemed moderate risk (92%) and 1 low risk level (8%). Due to the predominance of the highly repetitive movements of the upper limbs in fish processing work, and previous studies suggesting a reduced work pace to prevent UL-WMSDs, simulations of a pace with very low risk levels were carried out utilizing the OCRA checklist. By conducting these simulated interventions, it was possible to reduce the risk of UL-WMSDs to very low levels in all tasks by only decreasing the work pace (-42.8 ± 17.7%). These results suggest that most of the tasks carried out by workers were classified as moderate risk, predisposing workers to a greater probability of developing UL-WMSDs (10.8 to 21.5%) than the population that was not exposed. Simulations of a reduced work pace showed the effectiveness of this organizational measure in lowering the risk of UL-WMSDs.