Low level laser therapy for low-back pain

Sixty to eighty per cent of people suffer from back pain at some time in their lives. Of those who develop acute low-back pain (LBP), up to 30% will go on to develop chronic LBP. The toll on individuals, families and society makes the successful management of this common, but benign condition an important goal.

Low level laser therapy (LLLT) is used by some physiotherapists to treat LBP. LLLT is a non-invasive light source treatment that generates a single wavelength of light. It emits no heat, sound, or vibration. It is also called photobiology or biostimulation. LLLT is believed to affect the function of connective tissue cells (fibroblasts), accelerate connective tissue repair and act as an anti-inflammatory agent. Lasers with different wavelengths, varying from 632 to 904 nm, are used in the treatment of musculoskeletal disorders.

We included seven small studies with a total of 384 people with non-specific LBP of varying durations. Three studies (168 people) separately showed that LLLT was more effective at reducing pain in the short-term (less than three months), and intermediate-term (six months) than sham (fake) laser. However, the strength and number of treatments were varied and the amount of the pain reduction was small. Three studies (102 people) separately reported that LLLT with exercise was not better than exercise alone or exercise plus sham in short-term pain reduction.

One study (56 people) showed that LLLT was more effective than sham at reducing disability in the short term. Three studies (102 people) compared LLLT plus exercise with exercise plus sham or exercise alone and did not show significant reduction in disability. Two studies (90 people) separately reported that LLLT was not more effective at reducing disability than exercise alone or exercise plus sham in the short-term.

Based on these small trials, with different populations, LLLT doses and comparison groups, there are insufficient data to either support or refute the effectiveness of LLLT for the treatment of LBP. We were unable to determine optimal dose, application techniques or length of treatment with the available evidence. Larger trials that look specifically at these questions are required.

Authors' conclusions: 

Based on the heterogeneity of the populations, interventions and comparison groups, we conclude that there are insufficient data to draw firm conclusions on the clinical effect of LLLT for low-back pain.

There is a need for further methodologically rigorous RCTs to evaluate the effects of LLLT compared to other treatments, different lengths of treatment, wavelengths and dosages.

Read the full abstract...
Background: 

Low-back pain (LBP) is a major health problem and a major cause of medical expenses and disablement. Low level laser therapy (LLLT) can be used to treat musculoskeletal disorders such as back pain.

Objectives: 

To assess the effects of LLLT in patients with non-specific LBP.

Search strategy: 

We searched CENTRAL (The Cochrane Library 2005, Issue 2), MEDLINE, CINAHL, EMBASE, AMED and PEDro from their start to November 2007 with no language restrictions. We screened references in the included studies and in reviews and conducted citation tracking of identified RCTs and reviews using Science Citation Index. We also contacted content experts.

Selection criteria: 

Randomised controlled clinical trials (RCTs) investigating LLLT to treat 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. Studies were qualitatively and quantitatively analysed according to Cochrane Back Review Group guideline.

Main results: 

Seven heterogeneous English language RCTs with reasonable quality were included.

Three small studies (168 people) separately showed statistically significant but clinically unimportant pain relief for LLLT versus sham therapy for sub-acute and chronic low-back pain at short-term and intermediate-term follow-up (up to six months). One study (56 people) showed that LLLT was more effective than sham at reducing disability in the short term. Three studies (102 people) reported that LLLT plus exercise were not better than exercise, with or without sham in the short-term in reducing pain or disability. Two studies (90 people) reported that LLLT was not more effective than exercise, with or without sham in reducing pain or disability in the short term.

Two small trials (151 people) independently found that the relapse rate in the LLLT group was significantly lower than in the control group at the six-month follow-up.

No side effects were reported.

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