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

Conventional lower-limb exoskeletons often rely on lateral supports, which can shift the user's center of mass and induce gait asymmetry, thereby limiting practical deployment. This study preliminarily validated a rear-supported exoskeleton with a three-layer torque-impedance control strategy in healthy adults, providing initial evidence for potential rehabilitation applications. We designed the rear-supported lower-limb exoskeleton and evaluated its performance during level walking and on an 8.5° incline in six participants using synchronized surface electromyography and kinematic data. Results showed that rectus femoris root mean square of muscle activation decreased by 20.62% on level ground and 36.38% on the slope, while the Gait Symmetry Index improved by 8.82% and 14.37%, respectively. The combination of the rear-supported structure and hierarchical control reduced muscular demand and enhanced bilateral gait symmetry, suggesting a potential design paradigm for assistive walking and future rehabilitation.