¹Aalborg University, Aalborg, Denmark
²INRS (Institut National de Recherche et de Sécurité), Vandœuvre-lès-Nancy, France
³Institute of Occupational and Social Medicine and Health Services Research, University Hospital of Tübingen, Tübingen, Germany

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Introduction: Manual order picking in warehouse logistics involves repetitive lifting, awkward postures, and substantial physical exertion, contributing to a high prevalence of work-related musculoskeletal disorders (WMSDs). Occupational exoskeletons, such as passive back-supporting devices, induce acute ergonomic benefits as underlined in numerous short-term laboratory-bases studies. However, the literature still lacks long-term in-field evaluations of the devices. The present randomized controlled trial aimed to assess the effect of 24 weeks in-field use of a passive back-supporting exoskeleton (BSE) on biomechanics, perceived work intensity, and musculoskeletal discomfort among warehouse workers.

Methods: Twenty warehouse workers were randomized into an intervention group (BSE use) and a control group (no BSE). Biomechanical assessments including surface electromyography and kinematic recordings were conducted during standardized lifting tasks pre- and post-intervention. The workers rated perceived exertion at the test sessions, and completed questionnaires on musculoskeletal discomfort, usability, and work intensity at four-week intervals throughout the intervention.

Results: BSE use significantly reduced erector spinae and lower trapezius muscle activity across various lifting loads. Perceived exertion during lifting tasks was also significantly decreased with BSE use. Although no additional biomechanical improvements were observed over time, participants in the intervention group reported a significant reduction in perceived work intensity during the 24-week period. Ratings of comfort, movability, and job performance were moderate to positive, though some users reported issues related to decreased mobility and size of the device.

Discussion: This study is among the first to demonstrate sustained in-field use of a BSE over a 24-week period in a real-world logistics environment. The findings suggests that BSEs can consistently reduce muscular load and perceived exertion during manual order picking tasks. Importantly, the long-term use was associated with a reduction in perceived work intensity. These results support the potential of exoskeletons as a practical, long-term ergonomic intervention in physically demanding industries, which could be associated with decreased risk of developing WMSDs.

Conclusion: While BSEs show promise in reducing physical strain and perceived exertion during warehouse work, this study adds critical evidence of their long-term feasibility and benefits. Future research should build on these findings by optimizing design and implementation strategies to support widespread adoption and maximize ergonomic impact in occupational settings. Additionally, the effect of BSE use on WMSDs, worker attrition, and sick leave still needs to be investigated.