Evaluation of a spring-loaded upper-limb exoskeleton in cleaning activities

In the past few years, companies have started considering the adoption of upper-limb occupational exoskeletons as a solution to reduce the health and cost issues associated with work-related shoulder overuse injuries. Most of the previous research studies have evaluated the efficacy of these devices in laboratories by measuring the reduction in muscle exertion resulting from device use in stereotyped tasks and controlled conditions. However, to date, uncertainties exist about generalizing laboratory results to more realistic conditions of use. The current study aims to investigate the in-field efficacy (through electromyography and perceived exertion), usability, and acceptance of a commercial spring-loaded upper-limb exoskeleton in cleaning job activities. The operators were required to maintain prolonged overhead postures while holding and moving a pole equipped with tools for window and ceiling cleaning. Compared to the normal working condition, the exoskeleton significantly reduced the total shoulder muscle activity (-17%), the activity of the anterior deltoid (-26%), medial deltoid (-28%), and upper trapezius (-24%). With the exoskeleton, the operators perceived reduced global effort (-17%) as well as a reduced local effort in the shoulder (-18%), arm (-22%), upper back (-14%), and lower back (-16%). The beneficial effect of the exoskeleton and its suitability in cleaning settings are corroborated by the acceptance and usability scores assigned by operators, which averaged-5.5 out of 7 points. To the authors' knowledge, this study is the first to present an experience of exoskeleton use in cleaning contexts. The outcomes of this research invite further studies to test occupational exoskeletons in various realistic applications to foster scientific -grounded ergonomic evaluations and encourage the informed adoption of the technology.

Automated summary

In recent years, companies have been considering the adoption of upper-limb exoskeletons as a solution to reduce health and cost issues caused by work-related shoulder overuse injuries. Previous research mainly evaluated these devices in laboratory settings, but uncertainties remain about generalizing the results to real-world conditions. This study investigated the efficacy, usability, and acceptance of a commercial upper-limb exoskeleton in cleaning job activities, demonstrating significant reductions in shoulder muscle activity and perceived exertion.