Joint loading topography during occupational tasks - A musculoskeletal modeling approach to substantiate ergonomic recommendations

Abstract

Background: To improve ergonomic recommendations and decrease work-related musculoskeletal disorders, thorough documentation of full-body, joint loading topography during occupational tasks is needed. Therefore, the purpose of this study was to document full-body internal joint loading topography in terms of estimated joint contact forces during occupational tasks. In addition, this internal loading topography was also compared to loading proxies (e.g., external joint moments) commonly used to assess injury risk during occupational tasks. Methods: 3D motion capture and ground reaction forces were measured while 20 participants performed ten occupational tasks. A musculoskeletal modeling workflow with a detailed spine was used to calculate internal joint loading in terms of contact forces, and their association with external joint moments was evaluated. Findings: Lifting 10 kg from the ground imposed the highest full-body internal joint loading compared to all other lifting tasks, while lifting 10 kg from hip height to shoulder height imposed the lowest internal joint loading. Only during occupational tasks involving standing upright posture, loading proxies did correlate well with internal joint loading. Interpretation: The modeling workflow and the internal joint loading topography could inform ergonomic recommendations on optimized load distribution across different anatomical regions.