Efficacy of neuromuscular electrical stimulation for hemiplegic shoulder pain: A systematic review and meta-analysis of randomized controlled trials

BackgroundNeuromuscular electrical stimulation (NMES) for the treatment of hemiplegic shoulder pain (HSP) remains controversial. This study aims to clarify the efficacy of NMES in treating HSP.MethodsPubMed, Embase, Cochrane Library, Web of Science, CNKI, and Wanfang Data were searched from database inception to May 31, 2025. Randomized controlled trials (RCTs) on NMES for treating HSP were included, and subgroup analyses were performed based on follow-up duration. The National Institutes of Health Quality Assessment Tool (NIH-QAT) was employed to assess risk of bias, and data were analyzed using Stata 15. This study protocol was registered with PROSPERO (CRD420251070156).ResultsFive studies involving 290 patients were included. NMES was found to alleviate shoulder pain (SMD = -0.49; 95% CI: -0.86 to -0.11), enhance upper limb motor function (WMD = 4.47; 95% CI: 2.85 to 6.09), and increase the range of motion (ROM) in shoulder forward flexion (WMD = 11.82; 95% CI: 6.13 to 17.50) and shoulder external rotation (WMD = 5.41; 95% CI: 2.48 to 8.34). Except for shoulder flexion, all of these findings were influenced by a single study with low methodological quality. No significant effects were observed for shoulder abduction or activities of daily living. The subgroup analyses indicated that the analgesic effect of NMES was sustained over the long term.ConclusionNMES is shown to mitigate shoulder pain over the long term and significantly increase the ROM in shoulder forward flexion. The short-term effect on alleviating shoulder pain is marginally significant, and NMES may be beneficial for enhancing upper limb motor function and increasing the ROM of shoulder external rotation. Nevertheless, due to potential bias, the findings should be interpreted with caution.