Effect of low-level laser therapy on pain and function of patients with shoulder tendinopathy: A systematic review

ABSTRACT Among the various existing physiotherapeutic interventions, low-level laser therapy (LLLT) is broadly used for treating musculoskeletal disorders. Evidence suggests that LLLT is effective in modulating inflammatory mediators, contributing to tissue repair and thus being indicated for the treatment of inflammatory conditions in general. However, heterogeneous results have been reported regarding its efficacy for shoulder tendinopathies. Thus, the aim of this study was to systematically review randomized controlled trials on the effects of LLLT on pain and function outcomes of patients with shoulder tendinopathy. Two reviewers independently searched the PubMed, SciELO, Cochrane, and PEDro databases. We included randomized controlled trials of humans diagnosed with shoulder tendinopathy and treated with LLLT, with outcome measures of pain and/or function. The risk of bias of each study was assessed using the PEDro scale. Eight studies (73%) were considered as having low risk of bias and three (27%) were considered as having high risk. Eleven studies, involving 486 participants, were included in this review. LLLT showed statistically significant pain reduction in 45% of the studies, and only one study demonstrated a statistically significant increase in function. Further systematic reviews are still needed for assessing the additive effect of LLLT with exercise, as well as the effect of LLLT using recommended dosages in the treatment of shoulder tendinopathy.