Improving the Efficacy of an Active Back-Support Exoskeleton for Manual Material Handling Using the Accelerometer Signal

Occupational back-support exoskeletons see their potential application in many industrial sectors to mitigate low back pain risk for workers performing demanding tasks. This work aims to design and evaluate a control strategy that improves the efficacy of an active exoskeleton by exploiting the raw signal from an accelerometer placed on the user's torso. The designed strategy adapts the assistance to the user's dynamics during lifting and lowering tasks, increasing the assistance for the lifting phase and decreasing it for lowering. The strategy efficacy is demonstrated through experimental analysis on twenty subjects. Comparisons are made with the task executed without the exoskeleton and a state-of-the-art inclination-based strategy. Results demonstrate the efficacy of the proposed strategy in improving users' acceptance and reducing erector spinae muscle activity. Using the accelerometer signal, the exoskeleton can enhance the assistance provided to workers performing manual material handling in real working scenarios, increasing safety, efficiency, and productivity.