A Novel Passive Shoulder Exoskeleton Using Link Chains and Magnetic Spring Joints.

Area of Science:

• Biomechanics
• Occupational Health
• Robotics

Background:

• Work-related musculoskeletal disorders, particularly in the back and shoulders, are a significant occupational disability.
• Passive shoulder exoskeletons aim to prevent injuries during overhead work by supporting upper arm and tool weight.
• Existing exoskeletons struggle to align with human shoulder flexibility and can be bulky due to additional components.

Purpose of the Study:

• To propose a new passive shoulder exoskeleton design.
• To address limitations of conventional exoskeletons, including poor joint alignment and increased inertia.
• To develop a compact and effective solution for reducing shoulder strain during occupational tasks.

Main Methods:

• Introduction of a novel passive shoulder exoskeleton utilizing a magnetic spring joint and link chain.
• Leveraging redundant degrees of freedom in link chains for horizontal shoulder movement adaptation.
• Customizing magnetic spring joint installation height and initial angle to minimize torque loss during arm elevation.

Main Results:

• The proposed exoskeleton demonstrates enhanced adaptability to natural shoulder joint movements.
• The magnetic spring joint provides compact torque generation without additional mechanical parts.
• Minimized torque loss during arm elevation compared to conventional designs was observed.

Conclusions:

• The novel passive shoulder exoskeleton offers a promising solution for reducing work-related musculoskeletal disorders.
• Its design effectively supports overhead tasks while maintaining wearer comfort and natural movement.
• Further electromyographic evaluations confirmed its performance in overhead work and box lifting tasks.