Rigid and soft back-support exoskeletons affect biomechanical and perceptual demands, but in different ways, during...

Passive back-support exoskeletons (BSEs) are promising but underexplored interventions to reduce the high physical demands of roofing shingling. Eighteen participants performed simulations of shingle installation tasks under 12 different conditions. These conditions included all combinations of three BSE levels (Rigid, Soft, and no BSE), two task orientations (peak-facing vs. side-facing), and two roof slopes (18° vs. 26°). Using the rigid BSE significantly reduced lumbar muscle activation (11-17%) compared to no BSE, without altering trunk flexion. In contrast, the soft BSE reduced trunk flexion (∼4%) without altering lumbar muscle activation. Both BSEs reduced perceived low back exertion (∼16%); however, the rigid BSE increased leg discomfort (∼26%), and the soft BSE increased shoulder exertion (∼19%). Our results suggest that using BSEs can be beneficial for shingle installation tasks but also highlight the importance of considering device-specific biomechanical benefits and associated trade-offs to ensure effective application.