Effectiveness of Botulinum Toxin A Injection for Hemiplegic Shoulder Pain: A Meta‐Analysis of Randomized Controlled Trials

ABSTRACT Hemiplegic shoulder pain (HSP) is a common post‐stroke complication impairing function and quality of life. Botulinum toxin A (BTA), a neurotoxin that inhibits acetylcholine release and reduces spasticity, has been proposed for treating HSP, though its clinical effectiveness remains unclear. This meta‐analysis aimed to evaluate BTA's efficacy in managing HSP. Nine randomized controlled trials involving 272 patients were included. Compared to placebo, BTA significantly reduced pain at 1 week (SMD = −0.93; 95% CI [−1.67, −0.19]; p  = 0.01) and 4 weeks (SMD = −0.90; 95% CI [−1.51, −0.28]; p  < 0.01), but not at 12 weeks. External rotation ROM improved at all time points, peaking at 4 weeks (WMD = 6.20; 95% CI [3.11, 9.30]; p  < 0.01). Abduction ROM improved at 4 and 12 weeks. Spasticity decreased significantly throughout, with the largest reduction at 12 weeks (WMD = −0.78; 95% CI [−1.42, −0.14]; p  = 0.02). Functional gains were noted at 4 weeks. However, these results should be interpreted cautiously due to small samples and heterogeneous injection protocols across studies. In conclusion, BTA is effective for short‐term HSP management, particularly in relieving pain and improving motor function. Further large‐scale trials with standardized methods are needed.