A Novel Passive Back-Support Exoskeleton With a Spring-Cable-Differential for Lifting Assistance

Area of Science:

• Biomechanics
• Wearable technology
• Ergonomics

Background:

• Work-related lower back injuries are a significant issue, often linked to musculoskeletal disorders.
• Passive back-support exoskeletons (BSEs) offer a lightweight solution but can cause discomfort during walking due to resistance.
• Existing passive BSEs lack the ability to differentiate between lifting and walking motions.

Purpose of the Study:

• To develop and evaluate a novel passive BSE capable of distinguishing between lifting and walking actions.
• To reduce user discomfort and improve the functionality of passive BSEs for occupational safety.

Main Methods:

• A unique spring-cable-differential mechanism was designed as a torque generator for hip joints.
• The system was engineered to provide assistive torque during lifting and minimal resistance during walking.
• Parameter optimization was performed to account for human gait asymmetry, ensuring balanced forces.

Main Results:

• The novel passive BSE reduced erector spinae muscle activation by up to 41% during simulated 10 kg lifting tasks.
• No significant changes in leg or back muscle activation were observed during walking trials.
• The torque generator's placement on the back minimized leg-based weight.

Conclusions:

• The developed passive BSE effectively reduces muscle strain during lifting while maintaining comfort during walking.
• This technology has the potential to significantly decrease the incidence of lower back injuries in occupational settings.
• The device's ability to adapt to different movements offers a promising advancement in wearable assistive technology.