Effects of end-effector robotic arm reach training with functional electrical stimulation for chronic stroke survivors

Background: Upper-extremity dysfunction significantly affects dependence in the daily lives of stroke survivors, limiting their participation in the social environment and reducing their quality of life. Objectives: This study aimed to investigate the effect of end-effector robotic arm reach training (RAT) with functional electrical stimulation (FES) on upper-limb motor recovery in chronic stroke survivors. Methods: In this single-blinded randomized controlled trial, 28 chronic stroke survivors were randomized to receive RAT-with-FES and RAT-without-FES for 40 min/day, three times per week over a 4-week period, and the data of 26 participants were used in the final analysis. Upper-limb motor recovery was measured using the Fugl-Meyer assessment (FMA), and kinematics (movement time, speed, and distance) during reaching movements toward targets placed in three directions (ipsilateral, median, and contralateral sides) were measured using a robotic arm. Results: The upper-limb motor recovery (FMA and kinematics) improvement for the within-group comparisons tended to be greater in the RAT-with-FES group than in the RAT-without-FES group. However, in the between-group comparison, no significant differences were found in FMA, and significant differences were observed only for 2 distance parameters of kinematic factors: total (23.0% vs. 1.7%) and straight total (25.5% vs. 2.6%) distance on the ipsilateral side (p < 0.05). Conclusions: This study was unable to clearly reveal the positive effects of electrical stimulation combined with robotic arm training. However, we believe that it provides basic data that furthers our understanding of the role of hybrid neuroprostheses in stroke rehabilitation and the factors determining successful treatment.