Effects of high-intensity laser therapy on subacromial impingement syndrome: a systematic review and meta-analysis

This systematic review and meta-analysis aims to identify, critically appraise, and summarize the effects of high-intensity laser therapy on subacromial impingement syndrome. Three databases, PubMed, Embase, and Scopus were searched from inception to March 1, 2024. Clinical trials comparing the effects of high-intensity laser therapy to conventional therapy are eligible for inclusion. Two independent reviewers conducted study selection, data extraction, and quality assessment. Methodological quality was assessed using the Physiotherapy Evidence Database scale. Meta-analyses were performed to determine the effects of high-intensity laser therapy. Five randomized controlled trials and one controlled clinical trial were included, with a total of 284 patients with subacromial impingement syndrome. All included studies were evaluated as good or above for quality assessment. Compared to conventional therapy, high-intensity laser therapy demonstrated significantly better outcomes for pain at both post-intervention (SMD = -1.01, 95%CI = -1.85 to -0.17) and three-month post-intervention (SMD = -0.51, 95%CI = -0.90 to -0.13); shoulder and arm function at both post-intervention (SMD = 0.40, 95%CI = 0.14 to 0.66) and three-month post-intervention (SMD = 0.45, 95%CI = 0.06 to 0.84); shoulder abduction active range of motion (SMD = 3.26, 95%CI = 0.49 to 6.03). No significant difference was found for shoulder flexion and external rotation range of motion. This review highlights the promising effects of high-intensity laser therapy for the rehabilitation of subacromial impingement syndrome. Rehabilitation professionals and policymakers should increase their awareness of high-intensity laser therapy as an emerging technology that may facilitate greater outcomes than current widespread standards.