Quantifying the biomechanical effects of back-support exoskeletons on work movements using statistical parametric mapping

Introduction: In response to physically demanding industrial environments, back-support exoskeletons (BSEs) have emerged as assistive devices. However, their functional interaction with body structures and potential in preventing musculoskeletal disorders (MSDs) remain unclear. The objective of this study was to analyze biomechanical motion sequences throughout the entire process of different work movements and provide a comprehensive assessment of the influence of BSE. Method: Using statistical parametric mapping (SPM) methodology, we examined and quantify the magnitude of significant effects of BSEs on muscle activity (MA) and kinematic movement patterns during lifting, carrying, walking, and static bending in a standardized manner. Results: Significant changes with large effect sizes were identified during the downward phase of the lifting task, indicating decreased MA in the musculus (M.) biceps femoris and a reduced hip flexion. The usage of BSEs during carrying and walking resulted in a decreased MA of M. biceps femoris during the legs' pre- and mid-swing phases, accompanied by an increased knee and ankle flexion. These changes in MA and kinematics, especially when the BSEs exert pressure on the leg shells through their supporting function, may be indicative of strain in other body regions due to the BSEs. Practical Applications: We suggest that the evaluated effects may lead to the non-use of BSEs in the workplace and should therefore be considered in the development of alternative BSE designs.