Efficacy of modified posterior shoulder stretching exercises on shoulder function in subacromial impingement syndrome: A comprehensive meta-analysis

Background: Subacromial impingement syndrome (SIS) is a common cause of shoulder pain and dysfunction. Modified posterior shoulder stretching exercises have been proposed as a treatment method aimed at improving shoulder function and reducing pain in patients with SIS. However, the efficacy of these exercises remains controversial, necessitating a systematic meta-analysis to comprehensively evaluate their effectiveness.

Methods: A systematic search was conducted across PubMed, Cochrane Library, Embase, and Web of Science databases to identify randomized controlled trials (RCTs) and observational studies evaluating the efficacy of modified posterior shoulder stretching exercises in patients with SIS. Inclusion criteria required that participants be diagnosed with SIS, the intervention be modified posterior shoulder stretching exercises, and key outcomes such as shoulder function improvement and pain relief be reported. Meta-analysis was performed using RevMan 5.3 software, calculating standardized mean differences (SMD) with 95% confidence intervals (CI), and heterogeneity and bias risk were assessed.

Results: A total of 10 RCTs with 628 patients were included. The modified posterior shoulder stretching exercises demonstrated significant effects in reducing pain at rest (SMD = -1.00, 95% CI: -1.85 to -0.15, P = .02) and during activity (SMD = -1.45, 95% CI: -2.49 to -0.41, P = .006). Additionally, the exercises showed positive effects in improving internal rotation (SMD = 0.49, 95% CI: 0.22-0.75, P = .0003) and external rotation range of motion (SMD = 0.29, 95% CI: 0.00-0.58, P = .05), as well as enhancing shoulder function (CMS score: SMD = 0.95, 95% CI: 0.64-1.25, P < .00001) and reducing disability (quick DASH score: SMD = -0.85, 95% CI: -1.12 to -0.58, P < .00001). Sensitivity analysis indicated high robustness of the results, and Egger test did not reveal significant publication bias (P > .05).

Conclusion: Modified posterior shoulder stretching exercises are significantly effective in improving shoulder function and reducing pain in patients with SIS, with the study results showing high robustness and low risk of bias. However, further high-quality research is needed to validate these findings.