Rear-Supported Lower-Limb Exoskeleton: Design Implementation and Experimental Validation of Assistive Performance

Area of Science:

• Biomedical Engineering
• Rehabilitation Robotics
• Biomechanics

Background:

• Conventional lower-limb exoskeletons often use lateral supports, leading to center of mass shifts and gait asymmetry.
• These limitations hinder the practical application of exoskeletons in rehabilitation and assistive walking.

Purpose of the Study:

• To validate a novel rear-supported lower-limb exoskeleton with a three-layer torque-impedance control strategy.
• To assess the exoskeleton's impact on muscle activation and gait symmetry in healthy adults.

Main Methods:

• Design and implementation of a rear-supported lower-limb exoskeleton.
• Evaluation of the exoskeleton's performance during level walking and an 8.5° incline.
• Synchronized collection of surface electromyography and kinematic data from six healthy participants.

Main Results:

• Rectus femoris muscle activation (root mean square) decreased by 20.62% on level ground and 36.38% on an incline.
• Gait Symmetry Index improved by 8.82% on level ground and 14.37% on the incline.
• Demonstrated reduced muscular demand and enhanced bilateral gait symmetry.

Conclusions:

• The rear-supported exoskeleton design combined with hierarchical control effectively reduces muscular effort.
• The system significantly improves gait symmetry, indicating its potential for assistive walking devices.
• This approach offers a promising design paradigm for future lower-limb exoskeleton development in rehabilitation.