SPORTS MEDICINE DIGEST
Kristen M. Agena, MS, ATC, CSCS, CES; Cailee E. Welch Bacon, PhD, ATC; Tamara C. Valovich McLeod, PhD, ATC, FNATA
Athletic Training and Sports Health Care. https://doi.org/10.3928/19425864-20190207-04
Posted March 26, 2019
Abstract
Haslerud S, Magnussen LH, Joensen J, Lopes-Martins RA, Bjordal JM. The efficacy of low-level laser therapy for shoulder tendinopathy: a systematic review and meta-analysis of randomized controlled trials. Physiother Res Int. 2015;20:108–125.
Clinical Question: A systematic review and meta-analysis was conducted to understand the effectiveness of low level laser therapy (LLLT) in reducing pain in patients with shoulder tendinopathy.
Data Sources: Studies published between 1987 and 2012 were identified for review if they included (1) randomized controlled trials, controlled clinical trials, or trials with crossover design; (2) human patients experiencing pain and functional disability due to a diagnosed shoulder tendinopathy or subacromial impingement; and (3) incorporated LLLT within a range of 632 to 1,064 nm over the pathological tendon, acupuncture point, or trigger point to one group in a controlled trial.
Study Selection: Of 395 studies initially identified by the selected search terms, 17 studies met all inclusion criteria and were used in the meta-analysis.
Data Extraction: Pain was assessed with the Visual Analog Scale (VAS).
Main Results: Positive effects were reported in 11 studies, whereas no significant effects were reported in 6 studies, with 4 of those noted to have inadequate dosage. Eleven of 15 (73%) studies addressing pain relief favored LLLT over no treatment, placebo, or other modalities. Nine of these 11 studies had tests for overall effect (Z scores) that were statistically significant (P < .05) and had a minimally important change score of 14 or greater on the VAS. When trials with an inadequate dosage based on World Association for Laser Therapy (WALT) recommendations were removed, 10 of 11 (90%) studies reported statistically significant findings for pain reduction.
Conclusions: The primary outcome of pain reduction was significantly improved when LLLT was performed as a single therapy and when it was combined with exercise or a multimodal physiotherapy plan. Pain improved from 73% to 90% after LLLT when recommended WALT dosage parameters were followed. These findings support the use of LLLT for the treatment of shoulder tendinopathies when the recommended dosage is used.
Summary: Photobiomodulation (PBM) entails the physiological mechanisms that are affected by the therapeutic use of light known as PBM therapy (PBMT). PBMT may use single or multiple non-ionizing light sources, including laser diodes, superluminescent diodes, and light-emitting diodes, in the visible and infrared spectrum. According to the North American Association for Photobiomodulation Therapy (NAALT), PBM involves photo-physical and photochemical events in endogenous chromophores that may result in the reduction of pain or inflammation (inhibitory effect) or the promotion of wound healing and tissue regeneration (stimulatory effect).1 Since September 2014, the use of the terms PBM and PBMT has been encouraged by the NAALT and WALT over other terms, including LLLT, due the wide variety of electromagnetic energy sources, parameters, and therapeutic benefits it encompasses.
Clinicians treating shoulder tendinopathies may attempt to reduce pain with a variety of interventions. In 2002, the U.S. Food and Drug Administration initially approved the use of lasers for treating pain originating in the head and neck and pain associated with carpal tunnel syndrome and arthritis,2 but the list of conditions has been expanded over the past 15 years. Since 2002, systematic reviews and meta-analyses have addressed the effectiveness of PBMT to treat a variety of musculoskeletal conditions, but the meta-analysis by Haslerud et al.3 is the only study to focus solely on shoulder tendinopathies. When used as a monotherapy under the proper treatment parameters, PBMT had a significant effect on decreasing pain in comparison to placebo and ultrasonography. However, most clinicians use a multifaceted approach to treating patients, including the use of multiple modalities and a variety of exercise…