A systematic review and meta-analysis of randomized controlled trials on the effectiveness of high-intensity laser therapy in the management of neck pain

The purpose of this systematic review was to evaluate the effects of high-intensity laser therapy (HILT) on pain, disability, and range of movement in patients with neck pain. Randomized controlled trials (RCTs) of HILT for neck pain disorders were searched across databases such as PubMed, Web of Science, Scopus, CINAHL, Science Direct, Cochrane Library, the PEDro database, and Google Scholar (updated January 7, 2024). The main outcome was pain intensity, with neck disability and cervical range of motion as secondary outcomes. Researchers reviewed article titles and abstracts from different databases using the Rayyan web app. Study quality was assessed using the Cochrane risk of bias tool, and evidence-based recommendations were developed using the GRADE approach. A meta-analysis was conducted to calculate the pooled effect in terms of mean differences (MD) for the outcomes of interest, along with a 95% confidence interval (95% CI). Twenty studies met the selection criteria and were potentially eligible for inclusion in the meta-analysis. At the end of the treatment, there was a statistically significant (p < 0.01) pooled MD of -14.1 mm for pain intensity (17 RCTs) with the VAS (95% CI:-18.4,-9.7), 3.9° (95% CI:1.9,6.7) for cervical extension (9 RCTs), and -8.3% (95% CI:-14.1,-4.1) for disability diminish (12 RCTs) with the neck disability index in favor of HILT. Only the results for pain intensity are in line with the minimal clinically important differences (MCID) reported in the literature. Overall, the evidence was deemed significant but with low certainty, attributed to observed heterogeneity and some risk of bias among the RCTs. HILT demonstrates effectiveness in reducing neck pain and disability while enhancing cervical extension when added to other physical therapy interventions, especially therapeutic exercise, based on a moderate level of evidence. This review highlights that the most favorable results are obtained when HILT is employed to address myofascial pain, cervical radiculopathy and chronic neck pain. PROSPERO registration number: CRD42023387394 (Registration date, 14/01/2023).