Hybrid robot & FES rehabilitation after stroke: Short‐term performance, fatigue, and patient experience

Abstract

Combining functional electrical stimulation (FES) and robotics may enhance post-stroke motor recovery, particularly in the subacute phase, yet evidence on usability and user experience remains limited. This study evaluated the feasibility and short-term effects of robotic, FES, and hybrid assistance during a wrist flexion–extension tracking task in 32 subacute stroke patients, most with severe upper-limb impairments. Participants received one of the three assistance modalities across three training sessions. Quantitative measures of tracking performance, effort, and fatigue, along with patient-reported outcomes, were analysed. Tracking performance improved during assisted trials across all groups, confirming the immediate efficacy of each modality, with no significant differences between them. The benefit of assistance was greater in more impaired patients, particularly in the Robot and Hybrid groups. Cocontraction increased in the FES and Hybrid groups during assistance, suggesting enhanced muscular engagement, while no change was observed in the Robot group. No significant increases in muscular fatigue were detected. All modalities were well tolerated, enjoyable and perceived as useful, with hybrid assistance receiving consistently positive feedback. Although the short intervention limited conclusions on unassisted performance over time, these findings demonstrate the feasibility and acceptability of hybrid robot–FES training across a broad range of impairment levels.