Biomechanical and performance-related adaptations to repeated lifting and lowering tasks with a passive back-support exosuit.

Back-support exosuits (BSEs) can potentially reduce low-back muscular demand during lifting and lowering tasks. However, most studies assess their efficacy over a single session. We assessed the efficacy of a passive BSE on twelve participants who performed six sessions of lifting and lowering 8 kg boxes with and without a passive BSE. In both tasks, completion time decreased across sessions at the same rate; however, there were no differences in overall performance or comfort between conditions. Without the BSE, peak knee flexion decreased across sessions in both tasks. Comparatively, participants increased peak torso anterior rotation with the BSE and gradually increased peak knee flexion across sessions in both tasks. Erector spinae activity initially decreased 8% while lowering with the BSE but was not maintained. CONCLUSION: Initial muscle activation reductions were not maintained, but gradual kinematic changes suggest ongoing adaptations might become more pronounced with continued use.