Low level laser therapy for nonspecific low-back pain

Background Low-back pain (LBP) and related disabilities are major public health problems and a major cause of medical expenses, absenteeism and disablement. Low level laser therapy (LLLT) can be used as a therapeutic intervention for musculoskeletal disorders such as back pain. Objectives To assess the effects of LLLT in patients with non-specific low-back pain and to explore the most effective method of administering LLLT for this disorder. Search strategy We searched CENTRAL (The Cochrane Library 2005, Issue 2), MEDLINE and CINAHL from their start to January 2007 and EMBASE, AMED and PEDro from their start to 2005 with no language restrictions. We screened references in the included studies and in reviews of the literature and conducted citation tracking of identified RCTs and reviews using Science Citation Index. We also contacted content experts. Selection criteria Only randomised controlled clinical trials (RCTs) investigating low level laser therapy as a light source treatment for non-specific low-back pain were included. Data collection and analysis Two authors independently assessed methodological quality using the criteria recommended by the Cochrane Back Review Group and extracted data. Consensus was used to resolve disagreements. Clinically and statistically homogeneous studies were pooled using the fixed-effect model; clinically homogeneous and statistically heterogeneous studies were pooled using the random-effects model. Main results Six RCTs with reasonable quality were included in the review. All of them were published in English. Because of clinical heterogeneity in study populations, interventions used and reported outcomes, meta-analysis was not possible to determine an overall effect for pain, disability and range of motion. Three studies (n=168) separately showed a significant pain relief effect of LLLT compared to sham therapy for sub-acute and chronic low-back pain. These effects were only observed at short-term and intermediate-term follow-ups. Long-term follow-ups were not reported. There was insufficient evidence to investigate the difference between LLLT and comparison groups for pain-related disability. There is insufficient evidence to determine the effectiveness of LLLT on anterior-posterior lumbar range of motion compared to control group in short-term follow-up. The relapse rate in the LLLT group was significantly lower than in the control group at six months follow-up period according to the findings of two trials. One study (n=50) reported a significant improvement in pain in LLLT group versus exercise therapy. Authors' conclusions No side effects were reported. However, we conclude that there are insufficient data to draw firm conclusions. There is a need for further methodologically rigorous RCTs to evaluate the effects of LLLT compared to other treatments, different lengths of treatment, different wavelengths and different dosages. Comparison of different LLLT treatments will be more reasonable if dose calculation methods are harmonized.