Comparison of the effectiveness of high-intensity laser therapy versus low-level laser therapy in musculoskeletal disorders: a systematic review and network meta-analysis

Musculoskeletal disorders (MSDs) are a leading cause of global disability. Low-Level Laser Therapy (LLLT) and High-Intensity Laser Therapy (HILT) are widely used for pain relief, yet their comparative effectiveness remains unclear, warranting further investigation. This systematic review aims to compare the effectiveness of HILT and LLLT in the treatment of MSDs. A systematic search for randomized controlled trials (RCTs) comparing HILT and LLLT in MSDs was conducted across Web of Science, ScienceDirect, PubMed, Scopus, EBSCOhost, Cochrane Library, the Physiotherapy Evidence Database (PEDro), and Google Scholar (last updated on December 13, 2025). Pain intensity was the primary outcome, whereas disability and range of motion (ROM) were secondary outcomes. A meta-analysis was conducted using mean differences (MDs) for pain intensity outcomes (Visual Analogue Scale [VAS], Numeric Pain Rating Scale [NPRS], and the KOOS pain subscale) and standardized mean differences (SMDs) for disability and range of motion (ROM) to compare the effects of HILT and LLLT. A network meta-analysis was subsequently performed to compare and rank the relative effectiveness of all laser-based treatment modalities, whether applied alone or in combination with other therapeutic interventions. Study quality was assessed using the Cochrane Risk of Bias 2 tool, and the certainty of the evidence was evaluated according to the GRADE approach. Twenty-two RCTs (n = 1,353) were included, with 575 participants receiving HILT and 778 receiving control interventions, including LLLT (n = 526), placebo laser (n = 216), and active non-laser treatments (n = 82). The overall risk-of-bias assessment indicated that 54.5% of the included studies presented methodological issues. Statistically significant reductions in pain intensity at the end of treatment favored HILT over LLLT in some comparisons, including HILT applied alone (MD = 0.8; 95% CI 0.5–1.2), HILT combined with exercise (MD = 0.6; 95% CI 0.04–1.1), and HILT combined with other physiotherapeutic interventions compared with corresponding LLLT-based approaches (MD = 1.4; 95% CI 0.6–2.2). However, the magnitude of pain reduction was generally modest and frequently below established minimal clinically important difference (MCID) thresholds. Evidence regarding disability and ROM outcomes was limited and heterogeneous, precluding firm conclusions and showing no clear statistically or clinically meaningful differences between interventions. Network meta-analysis ranked mild-dose HILT combined with exercise among the highest for pain reduction (SUCRA = 79.3%); however, ranking estimates were characterized by substantial uncertainty. According to GRADE, the clinical importance of the observed effects across pain, disability, and ROM outcomes ranged from not important to moderate, while the certainty of evidence was predominantly very low due to heterogeneity, imprecision, indirectness, and suspected publication bias. HILT demonstrated statistically greater pain reduction than LLLT in some comparisons, particularly when combined with exercise or other physical therapy modalities. However, these effects were generally modest and supported by very low certainty of evidence. Evidence regarding disability and ROM outcomes remains insufficient, particularly in terms of clinical relevance. Based on the current evidence, both HILT and LLLT may be considered therapeutic options for pain management in MSDs; however, treatment decisions should be made cautiously within a multimodal rehabilitation framework. Furthermore, adherence to WALT dosage recommendations for LLLT is advised to enhance treatment consistency and optimize clinical outcomes.