Initial static, pseudo-static, dynamic, and cognitive fit evaluation of three passive shoulder exoskeletons while performing simulated manufacturing tasks.

Shoulder disorders have been associated with repetitive overhead work and manual lifting. Passive exoskeletons may reduce exposure to physical risk factors associated with shoulder injuries. This repeated-measures study evaluated the initial static, pseudo-static, cognitive, and dynamic fit of three passive shoulder exoskeletons compared to a no-exoskeleton condition. Twenty-four participants (sex-balanced) performed range of motion tasks, simulated manufacturing activities, and a cognitive performance test. Results indicated that sex did not significantly affect any fit outcomes. Cognitive performance metrics remained unaffected across conditions. Exoskeletons improved certain static range of motion tasks, notably cross-body adduction and external rotation, while hindering others, such as extension. Mixed results were found for mean arm elevation during cognitive, pseudo-static, and dynamic tasks. The findings offer valuable insights into the nuanced trade-offs of passive exoskeletons and highlight the importance of task-specific fit evaluations for broader industrial adoption.