Effects of acupuncture on shoulder impingement syndrome: A systematic review and meta-analysis

Shoulder impingement syndrome (SIS) is a common condition that causes chronic shoulder pain. The effectiveness of acupuncture in treating chronic shoulder pain has been documented in previous studies; however, existing systematic reviews and meta-analyses have often excluded Chinese databases and combined different types of acupuncture interventions, such as electroacupuncture, warm acupuncture, pharmacopuncture, and acupotomy. Thus, this study specifically examines the exclusive impact of manual acupuncture on SIS.

Several databases, including PubMed, Cochrane Central, Embase, 1 Chinese database (China National Knowledge Infrastructure), and 5 Korean databases (ScienceON, Oriental Medicine Advanced Searching Integrated System, KoreaMed, Korean Studies Information Service System, and KMBASE), were systematically searched for relevant studies. The quality of the included studies was evaluated using the Cochrane Assessment Tool for Risk of Bias Version 2. Data collected from the selected studies were synthesized for meta-analysis. The primary outcome was a pain scale score, and the secondary outcomes were shoulder function and disability.

This study included 5 randomized controlled trials. The primary outcome assessment revealed significantly reduced pain (standardized mean difference [SMD] = -0.50, 95% confidence interval [CI] = -0.74 to -0.27) and improvements in shoulder function and disability (SMD = -0.57, 95% CI = -0.96 to -0.19). A subgroup analysis based on treatment duration indicated that short-term acupuncture treatment (≤4 weeks) exhibited a high level of confidence with low heterogeneity (SMD = -0.37, 95% CI = -0.73 to -0.02).

Manual acupuncture is effective for relieving pain and improving shoulder function and disability in patients with SIS. However, further research is necessary to validate these findings owing to the limited number of patients and heterogeneity among the studies reviewed.