A multifaceted hybrid ES-robotic device for gait training in individuals with neurological disorders.

The integration of robotics and Electrical Stimulation (ES) in neurorehabilitation leverages robotics' precise task execution alongside ES-induced motor learning, muscle conditioning, and cardiovascular benefits. We propose a hybrid system for overground gait training, combining neuromuscular ES and a motorized exoskeleton. Different combination modalities are proposed: ES-motor cooperation for the swinging knee, synchronized but independent ES and motor assistance for hip movements and for the knee during stance, and ES-only for the non-actuated ankle. Twelve non-disabled subjects and eleven participants with neurological disorders tested the system under two conditions: exoskeleton-only and hybrid. The hybrid condition reduced knee motor torque by 48% during swing without compromising tracking accuracy, showing that ES can effectively drive limb motion. Neurological participants rated the hybrid system as more usable than the exoskeleton alone (median 5-point improvement of System Usability Scale). These findings support the feasibility of hybrid ES-motorized exoskeletons in clinical settings. Future studies should investigate their potential to enhance therapeutic outcomes.