Going beyond the mean in examining the effects of exoskeleton use on motor and attentional task performance

This study examined how exoskeleton use affected motor and attention task performance and variability. Participants completed simulated industrial tasks in overhead or squatting postures, with and without exoskeleton support. Participants' mean performance, intra-individual variability, and inter-individual variability in motor and attention task performance were compared between conditions. The use of an upper-body exoskeleton during the overhead task resulted in overall slower motor performance, while using a lower-body exoskeleton during the squatting task increased intra-individual variability in motor performance. Mixed results were observed for attention performance and mental workload measures, indicating both potentially beneficial and detrimental effects. Findings suggest that exoskeleton use can affect both motor and attention task performance, as well as intra-individual variability, which may be related to restricted movement, poor exoskeleton fit, and pain, though these effects may be task- and system-specific. Performance variability metrics may offer unique insights beyond mean performance measures in evaluating exoskeleton impacts.