Evaluation of a Semi-Active Upper-Limb Exoskeleton While Performing Material Handling Tasks

Work-related musculoskeletal disorders (WRMSDs) are still today one of the primary health risks for workers worldwide. Adopting exoskeletons is emerging as a preventive measure in alleviating the musculoskeletal system's workload. This work investigates the effect of a semi-active exoskeleton, a new class of wearable devices, in a simulated industrial environment. The study found a consistent decrease in the average activity of the Anterior Deltoid, Upper Trapezius, and Rectus Abdominis in four different material handling and lifting tasks when the exoskeleton was used. Using the exoskeleton to move a weight between two shelves reduced the activity of 10 measured muscles belonging to the arm and trunk, with a notable 42.6% reduction for the Anterior Deltoid and 46.4% for the Upper Trapezius. The study also showed reduced peak force and slower lifting motion, potentially decreasing the likelihood of WRMSDs. Lastly, using the exoskeleton did not require additional cognitive exertion from the subjects, who also consistently reported a 44.9% reduction in their perceived Effort and a 34.0% reduction in Physical Demand. Despite some negative feedback regarding limited mobility, the study demonstrated the potential of semi-active exoskeletons, achieving good results in tasks and with weights where passive upper-limb exoskeletons are not typically used.