Comparing the effectiveness of high-and low-intensity laser therapy in enhancing conventional treatment for frozen shoulder: A systematic review, meta-analysis, and meta-regression

Abstract

Introduction: This study reviews the efficacy of high-intensity laser therapy (HILT) and low-level laser therapy (LLLT) for frozen shoulders, including a meta-regression to identify variables affecting treatment outcomes. Methods: Eight randomized controlled trials (RCTs) with 444 participants with frozen shoulders received HILT or LLLT, combined with conventional therapies. Outcomes measured visual analogue scale (VAS)-pain scores, shoulder pain and disability index (SPADI), short form health survey questionnaire (SF-36), and shoulder range of motion (ROM). The bias was analyzed with risk of bias version 2 and the analysis was performed with JAMOVI 2.4.14 and RevMan 5.4. Results: Laser therapy showed significant improvements in outcomes: VAS scores (risk ratio [RR]-1.36, 95% confidence interval [CI]-1.95,-0.76), SPADI-pain (RR-10.20, 95% CI-15.95,-4.44), shoulder abduction ROM (RR 8.74, 95% CI 1.37, 16.11), and SF-36 role limitation due to physical health (RR 28.55, 95% CI 9.99, 47.12). The intensity of laser therapy influenced outcomes, with confounding factors affecting follow-up time and SF-36 emotional well-being. Conclusion: Laser therapy, especially HILT, significantly reduces pain, improves shoulder range of motion, and enhances quality of life.