Evaluation of a Novel Active Exoskeleton for Tasks at or Above Head Level

Tasks at or above head level have been known to cause discomfort and musculoskeletal disorders. This letter presents a novel wearable active pneumatic exoskeletal support system with a power tool based control interface to make work at head level or above more comfortable. Subjective task effort (Borg CR10), movement velocities, and muscle activity (surface electromyography) have been evaluated and different passive and active operation modes are being compared. We show that the exoskeleton is capable of performing a substantial reduction in muscle activity, increasing upper arm elevation velocities, and reducing task effort. The comparison of an active support mode with a trigger button at the tool grip with a passive support mode showed that users reported less resistance for lowering the arm and increased velocities when they were able to adjust the support with a simple button. We show that for tasks with a varying weight of loads, an adaptive active exoskeleton is greatly beneficial over a passive one as it eases usability and acceptance.