The Effects of Passive and Active Back Support Exoskeletons on Endurance, Perceived Exertion, and Back Discomfort During Fatigue-Induced Repetitive Lifting

Back-support exoskeletons (BSEs) show promise for mitigating physical strain in industrial settings, yet their effectiveness during fatigue-inducing tasks remains underexplored. This study evaluated the effects of powered and unpowered BSEs on endurance, perceived exertion, and back discomfort during repetitive lifting. Sixteen participants lifted a box (15% body mass) at ~8 lifts/min until exhaustion under three conditions: no exoskeleton, unpowered, and powered. Endurance time (i.e., time-to-fatigue), number of lifting cycles, perceived exertion (RPE), and back discomfort (RPD) were recorded. The powered BSE significantly increased time-to-fatigue ( p = .03) and number of lifting cycles ( p = .03) compared to control. RPE increased over time across all conditions ( p < .001) but was significantly lower with powered versus control ( p = .015). The unpowered device showed a non-significant trend toward reduced RPE. Neither device significantly alleviated back-discomfort. These findings suggest powered exoskeletons may better regulate fatigue during repetitive lifting; however, further research should explore long-term biomechanics effects and user adaptation.