Physiological Effects of a Back-Support Exoskeleton Control to Assist Carrying Activities

To mitigate the risk of musculoskeletal disorders and injuries at the back, occupational back-support exoskeletons are being introduced in the workplace because of their ability to reduce workers’ lumbar loading during the execution of demanding activities. Nevertheless, back-support exoskeletons’ assistance has not been developed extensively for activities different from lifting.This work presents a control strategy for an active back-support exoskeleton specifically tailored for assisting carrying task and analyzes the physiological effects on the user. The control strategy modulates the exoskeleton torques to assist the back without hindering the user’s legs’ during gait. A gait phase detection framework that uses sensorized insoles is employed to control the modulation of the assistive torques. The strategy is assessed through an experimental test on nine subjects. Participants performed a simplified carrying task without and with the exoskeleton. The experimental evaluation found a statistically significant increase in the normalized heart rate when using the exoskeleton compared to not using it. No statistically significant changes were found in the mental effort between the conditions with and without the exoskeleton aid.