PREMUS 2025: 12th International Scientific Conference on the Prevention of Work-Related Musculoskeletal Disorders
Assessing the level of support of a lower back exoskeleton among landscaping workers in real-world working conditions
2Centre interdisciplinaire de recherche en réadaptation et intégration sociale (CIRRIS), Québec, Canada
3Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Montréal, Canada
4University of Québec in Montréal, Montréal, Canada
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Background: Musculoskeletal disorders (MSDs) remain a major concern worldwide. Landscaping workers are at high risk of back injuries [1]. Various prevention strategies are being explored, with growing interest towards exoskeletons. Studies on passive back exoskeletons show a modest reduction in back loading during tasks that mainly involve a stoop posture [2]. The use of a free-style or squat posture with a passive back exoskeleton does not appear to have a significant effect on reducing back loading [3], [4]. There is also a lack of literature documenting their effects on workers’ risks of MSDs in real-world tasks performed in the workplace. The aim of this study was to measure the effectiveness of a back exoskeleton during a real weeding task in reducing exposure to MSD risk factors.
Methodology: Four landscaping workers (including one woman), with no reported pain or health issues in the previous six months, were recruited. A surface electromyography system was used, with bilateral placement on the following muscles: upper trapezius, middle deltoid, anterior deltoid, external obliques, and spinal erectors (iliocostalis at L3 and longissimus at L1). For kinematic data, an Xsens Awinda wireless motion capture system was used to measure full-body movement. Seventeen sensors were placed on bony landmarks of body segments to minimize soft tissue artifacts. Before biomechanical data collection with the Laevo FLEX back exoskeleton, a familiarization phase allowed all participants to use the exoskeleton over a period of three weeks. The data collection involved working without and with the exoskeleton during weeding tasks. Several conditions and work phases were analyzed, including a 15-minute free posture working phase followed by three 5-minute phases with imposed postures: squat, stoop, and kneeling. Participants completed a questionnaire on their perceptions of exoskeleton use, including exertion, discomfort and preference (with or without). The postures of the back, knees and shoulders were analyzed, as well as the muscular effort required. The 50th and 95th percentile values were extracted from kinematic data and EMG measurements for each task and compared with and without the exoskeleton.
Results: Participants reported an increase in effort when wearing the exoskeleton compared to tasks when not wearing the exoskeleton. The four participants reported that they were not interested in trying the exoskeleton in the future (due to the discomfort they felt and the time it took to fit and adjust). Biomechanical data are under analysis.
Discussion/Conclusion: Testing the exoskeleton in real-world working conditions is an essential step in determining worker acceptance and assessing the level of support during authentic movements.
References
[1] Lim MC, Awang Lukman K, Giloi N, Lim JF, Salleh H, Radzran AS, Jeffree MS, Syed Abdul Rahim SS. Landscaping Work: Work-related Musculoskeletal Problems and Ergonomic Risk Factors. Risk Manag Healthc Policy. 2021 Aug 17;14:3411-21. DOI: 10.2147/RMHP.S314843[2] Tröster M, Budde S, Maufroy C, Andersen MS, Rasmussen J, Schneider U, Bauernhansl T. Biomechanical Analysis of Stoop and Free-Style Squat Lifting and Lowering with a Generic Back-Support Exoskeleton Model. Int J Environ Res Public Health. 2022 Jul 25;19(15):9040. DOI: 10.3390/ijerph19159040
[3] Banks JJ, Quirk DA, Chung J, Cherin JM, Walsh CJ, Anderson DE. The effect of a soft active back support exosuit on trunk motion and thoracolumbar spine loading during squat and stoop lifts. Ergonomics. 2025 Feb;68(2):223-36. DOI: 10.1080/00140139.2024.2320355
[4] Luger T, Bär M, Seibt R, Rimmele P, Rieger MA, Steinhilber B. A passive back exoskeleton supporting symmetric and asymmetric lifting in stoop and squat posture reduces trunk and hip extensor muscle activity and adjusts body posture - A laboratory study. Appl Ergon. 2021 Nov;97:103530. DOI: 10.1016/j.apergo.2021.103530
