Anatomy

Work (physics)

Upper limb

Powered exoskeleton

Wearable computer

Engineering

Exoskeleton

Embedded system

Elbow

Elbow flexion

Computer science

Biceps

Simulation

Medicine

Mechanical engineering

Physical medicine and rehabilitation

IEEE Robotics and Automation Letters

Physically demanding work is still common in western countries, with large proportions of the workforce that are exposed for more than a quarter of their working time to tiring postures or repetitive tasks: the shoulder is one of the main body areas susceptible to work-related musculo-skeletal disorders. Recent advancements in assistive technology have provided new instruments to promote safety and reduce workload. Colloquially referred to as occupational exoskeletons (OEs), these wearable devices are usually spring-loaded, and provide gravity support for overhead tasks. OEs for upper limbs are usually single-joint exoskeletons and assist shoulder flexion/extension; they do not provide support to distal joints such as the elbow. In the present work, starting from a commercially available exoskeleton, we propose an innovative concept of hybrid upper-limb OEs. We combined a spring-loaded shoulder exoskeleton with an active elbow exosuit to extend the capability of the OEs to provide gravitational support to both shoulder and elbow flexion-extension in strenuous manual tasks. The proposed device can reduce up to 32% of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">biceps</i> activity during the elbow flexion and up to 31% of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">deltoids</i> activity during the shoulder abduction. In-lab experimentation showed the potentials of such a hybrid approach in reducing the strain of the upper-limb muscles.

Rigid, Soft, Passive, and Active: A Hybrid Occupational Exoskeleton for Bimanual Multijoint Assistance