The effectiveness of low-level laser therapy on pain, self-reported hand function, and grip strength compared to placebo or "sham" treatment for adults with carpal tunnel syndrome: A systematic review

Background: Carpal tunnel syndrome (CTS) is one of the most common peripheral neuropathies in the upper extremity.

Objective: The aim of this review was to systematically and critically appraise the available literature for the effectiveness of Low-Level Laser Therapy (LLLT) on pain, self-reported hand function, and grip strength compared to placebo treatment in adults with CTS.

Methodology: Seven databases were searched from 2000 to March 2015 namely: Cinahl, Cochrane Library, EBSCOhost, PEDro, PubMed, Science Direct, and Scopus. Key search terms were: CTS, LLLT, and physiotherapy. Specific inclusion and exclusion criteria were applied. The methodological quality was appraised with the PEDro scale. Data were extracted and captured on an Excel spreadsheet.

Results: The nine included randomized control trials (RCTs) had an average score of 8.2/11 according to the PEDro scale. The heterogeneity of the LLLT regimes used made statistical pooling inappropriate for this review and results were described narratively.

Conclusion: No strong evidence exists concerning the effects of LLLT on CTS in adults. Studies that used 780-860 nm Lasers and energy dosages of 9-11 J/cm² or 10.8 J reported a more favorable outcome for pain, symptom severity, and functional ability as well as grip strength at the end of treatment and short-term follow up.