The effect of gallium arsenide aluminum laser therapy in the management of cervical myofascial pain syndrome: a double blind, placebo-controlled study

The efficacy of low-level laser therapy (LLLT) in myofascial pain syndrome (MPS) seems controversial. A prospective, double-blind, randomized controlled trial was conducted in patients with chronic MPS in the neck to evaluate the effects of low-level 830-nm gallium arsenide aluminum (Ga–As–Al) laser therapy. The study group consisted of 64 MPS patients. The patients were randomly assigned into two groups. In group 1 (n = 32), Ga–As–Al laser treatment was applied over three trigger points bilaterally for 2 min over each point once a day for 15 days during a period of 3 weeks. In group 2 (n = 32), the same treatment protocol was given, but the laser instrument was switched off during applications. All patients in both groups performed daily isometric exercise and stretching exercises for cervical region. Parameters were measured at baseline and after 4 weeks. All patients were evaluated with respect to pain (at rest, movement, and night) and assessed by visual analog scale, measurement of active range of motion using an inclinometer and a goniometer, and the neck disability index. In both groups, statistically significant improvements were detected in all outcome measures compared with baseline (p < 0.05). However, no significant differences were obtained between the two groups (p > 0.05). In conclusion, although the laser therapy has no superiority over placebo groups in this study, we cannot exclude the possibility of effectivity with another treatment regimen including different laser wavelengths and dosages (different intensity and density and/or treatment interval).