Abstract: Objective To apply the surface electromyography (sEMG) in the evaluation of hand motor function for patients with hemiplegia after stroke. Methods From January to August, 2018, 43 hemiplegic patients with hand dysfunction after stroke were selected. All the patients received comprehensive rehabilitation for four weeks. Their root mean square (RMS) and integrated electromyography (iEMG) of wrist flexor (WF), wrist extensor (WE), extensor digitorum (ED) and abductor pollicis brevis (APB) were measured before and after treatment, while they were assessed with Fugl-Meyer Assessment (FMA) and Brunnstrom's stages for the affected hand. Results The FMA score and Brunnstrom's stages, as well as the RMS and iEMG of WF, WE, ED and APB increased after treatment (Z > 2.496, t > 5.361, P < 0.05). The FMA score positively correlated with the RMS and iEMG of WF, WE, ED and APB (r = 0.423-0.732, P < 0.05). The Brunnstrom's stages positively correlated with the RMS of WE, ED and ABP (r = 0.343-0.467, P < 0.05) and the iEMG of WF, WE and ABP (r = 0.223-0.328, P < 0.05). Multiple linear stepwise regression drew the RMS of ED and iEMG of WE as the related factors for FMA (t > 4.243, P < 0.001), and RMS of ED as the related factors for Brunnstrom's stages (t = 4.707, P < 0.001). Conclusions EMG is an effective tool to evaluate the motor function of hand for stroke patient as an objective and quantitative assessment, especially those of WE and ED.

Key words: stroke, surface electromyography, hand, motor function, assessment