Evaluation of gait training based on the combination of TWIN exoskeleton and Functional Electrical Stimulation of tibialis anterior.

Lower limb exoskeletons are increasingly used in neurorehabilitation to assist walking in individuals with neurological impairments. The TWIN lower limb exoskeleton developed at the Rehab Technologies Lab of Istituto Italiano di Tecnologia (IIT) is an innovative prototype that has been previously tested on people with spinal cord injury (SCI) and post-stroke conditions. However, the absence of active ankle control limits its effectiveness, especially in addressing foot drop and foot slap. Functional electrical stimulation (FES) of the tibialis anterior (TA) has been shown to mitigate these deficits by promoting dorsiflexion during gait. This study evaluates the integration of TWIN with a FES system to improve ankle mobility. Ten healthy subjects walked on a treadmill with the TWIN+FES system for 30 minutes. Kinematic data showed that FES improved dorsiflexion during the swing phase, leading to more physiological ankle trajectories. Although some subjects exhibited signs of muscle fatigue, there were no significant changes in ankle performance over time. These findings support the feasibility of integrating FES with TWIN and lay the groundwork for future investigations into its impact on gait patterns and potential rehabilitation benefits. Future studies should investigate the effects of this approach in individuals with neurological impairments, and assess its impact on reducing exoskeleton motor demands.Clinical relevance-The combination of lower limb exoskeletons with functional electrical stimulation has the potential to enhance gait rehabilitation in individuals with SCI or post-stroke conditions. By improving ankle dorsiflexion in healthy subjects, this approach shows promise for reducing foot drop and foot slap in future clinical applications; further studies are needed to evaluate its actual effectiveness in individuals with neurological impairments.