Active and Passive Back-Support Exoskeletons: A Comparison in Static and Dynamic Tasks

Abstract

Studies on back-support exoskeletons focus mostly on the evaluation of single devices. Also, these studies suggest that passive exoskeletons might be preferred when performing static tasks, whereas active ones, could show their advantage in dynamic tasks. To verify this hypothesis and provide a comparison between different devices, in this study, we analyse the performance of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">XoTrunk</i> and the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Laevo v2.56</i> , an active back-support exoskeleton and a passive one, respectively. We analyse these devices highlighting their ability to reduce back muscle activation, perceived discomfort and usability. The study was carried out by simulating a dynamic and a static task. The results show that both exoskeletons reduce back-muscle activation levels, although the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">XoTrunk</i> provides a reduction that was more than twice as large as the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Laevo</i> (e.g., 41% vs 16%, respectively). The results also show that, overall, in the dynamic condition, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">XoTrunk</i> has better scores than the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Laevo</i> . Conversely, in the static task, the participants in the study had a preference for the passive device, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Laevo</i> . The results presented in this work can help exoskeleton end-users to properly select the best device to fit their needs.