Systematic review and meta-analysis of laser physical agent for pain and disability in rotator cuff tendinopathy: subgroup analysis and meta-regression exploration of randomized control trials

INTRODUCTION: Laser therapy is increasingly used in the management of rotator cuff tendinopathy; however, the comparative effectiveness of different laser types and treatment parameters remains unclear. This study aimed to evaluate the effects of low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) on pain and disability. METHODS: A systematic search of PubMed, Medline-Ovid, PEDro, and ClinicalTrials.gov was conducted from inception to July 2025. Randomized controlled trials comparing LLLT or HILT with placebo laser, exercise-based interventions, or other physical agents were included. Pain and disability outcomes were pooled using random-effects models. Subgroup and meta-regression analyses explored the influence of laser type, treatment regimen, control conditions, emission mode, wavelength, treatment duration, session frequency, and study quality. RESULTS: Laser therapy significantly reduced pain (Hedges' g = -0.701) and disability (Hedges' g = -0.691). HILT showed greater effect sizes than LLLT across outcomes. Pulsed-mode LLLT showed significant effect on pain reduction. Meta-regression analyses did not identify significant associations between sessions per week and treatment outcomes. CONCLUSION: HILT, applied alone or as an adjunctive therapy, provides significant benefits for pain and disability in rotator cuff tendinopathy, whereas standalone LLLT shows limited effectiveness. Further studies should examine long-term outcomes and standardized laser dosing.