Task-Related Training Combined with Transcutaneous Electrical Nerve Stimulation Promotes Upper Limb Functions in Patients with Chronic Stroke

Severe upper limb paresis is a major contributor to disability after stroke. This study investigated the efficacy of task-related training (TRT) with transcutaneous electrical nerve stimulation (TENS) on recovery of upper limb motor function in chronic-stroke survivors. Thirty patients with chronic stroke were randomly allocated two groups: the TRT+TENS group (n = 15) and the TRT+placebo (TRT+PLBO) group (n = 15). Patients in the TRT+TENS group received TENS stimulation (two to three times the sensory threshold), while subjects in the TRT+PLBO group received TENS without real electrical stimulation. TENS was applied to muscle belly of triceps and wrist extensors, while placebo (PLBO) stimulation was administrated without real electrical stimulation. Both interventions were given for 30 minutes per day, 5 days per week, for a period of 4 weeks. The primary outcomes were assessed with Fugl-Meyer assessment scores (FMA), Manual function test (MFT), Box and block test (BBT), and Modified Ashworth scale (MAS), each of which was performed one day before and one day after intervention. Both groups showed significant improvements in FMA, MFT, and BBT after intervention. When compared with the TRT+PLBO group, the TRT+TENS group showed significantly greater improvements in FMA (p = 0.034), MFT (p = 0.037), and BBT (p = 0.042). In MAS score, significant improvement was observed only in the TRT+TENS group (p = 0.011). Our findings indicate that TRT with TENS can reduce motor impairment and improve motor activity in stroke survivors with chronic upper limb paresis, highlighting the benefits of somatosensory stimulation from TENS.