Effects of Passive Upper-Extremity Exoskeleton Use on Motor Performance in a Precision Task

Abstract

Upper-extremity exoskeletons (UEXO) are promising interventions for reducing the physical demands of work performed with arms elevated (e.g., overhead work). In this study, we investigated the effects of passive UEXO use on motor performance and physical demands in a repetitive precision overhead task. Eleven participants completed repetitive tapping of targets in both vertically-aligned (targets above/below shoulder level) and horizontally-aligned (targets at shoulder level) configurations, using two UEXOs (Levitate AirframeTM and Eksobionics EksoVestTM) and in a no-device (control) condition. Median levels of muscle activity in the upper trapezius and anterior deltoid muscles decreased using both UEXOs compared to the control. However, the two UEXOs caused distinct effects on end-point precision. End-point precision was similar between devices in the horizontal configuration, but using the EksoVest significantly decreased precision in the vertically-aligned task. These results indicate that task performance may be device-specific, and should be considered when using industrial exoskeletons in diverse tasks.