Obesity and physical loading during manual lifting

Abstract

Manual lifting greatly increases the risk of developing work-related musculoskeletal disorders (WRMSD). Muscle loading related to manual tasks may be significantly influenced by workers’ body conditions, being obesity one of them. In the present study, different tasks of manual lifting were performed by 14 participants with different obesity levels, defined in terms of individuals’ fat mass percentage. Surface electromyography (EMG) data were collected bilaterally from 3 muscles recruited during this type of tasks. EMG data normalization was based on the percentage of maximum contraction during each task (MCT). Furthermore, the participants reported physical loading by using the Rated Perceived Exertion scale (RPE). These techniques sought to analyze the physical loading during manual lifting tasks. The obtained results indicate that obesity level influenced the MCT percentage, which in turn increases the muscle loading during manual lifting tasks. However, obesity level does not seem to influence the RPE values. In this context, further studies based on biomechanical approaches are required to provide a more complete understanding of the obesity effects on musculoskeletal loading during manual lifting.