Does Red Light Therapy Help with Low Back Pain?
This 2007 Cochrane systematic review of six randomized controlled trials found some evidence that low level laser therapy relieves pain compared to sham therapy in subacute and chronic low back pain, at short-term and intermediate-term follow-up. There was no difference between LLLT and comparison groups for pain-related disability, and the authors concluded that there are insufficient data to draw firm conclusions.
Red light therapy, also known as low-level laser therapy (LLLT) or photobiomodulation (PBM), uses specific wavelengths of light as a therapeutic intervention for musculoskeletal disorders such as back pain.
Low back pain and the disabilities that come with it are major public health problems and a major cause of medical expenses, absenteeism, and disablement. This review set out to assess the effects of LLLT in patients with nonspecific low back pain and to explore the most effective way of administering it.
What the Research Shows
The reviewers searched CENTRAL, MEDLINE, and CINAHL from their start to January 2007, and EMBASE, AMED, and PEDro from their start to 2005, with no language restrictions. They screened references in the included studies and in literature reviews, tracked citations of identified trials and reviews, and contacted content experts. Only randomized controlled trials of low level laser therapy as a light source treatment for nonspecific low back pain were eligible. Two authors independently assessed methodological quality using the criteria recommended by the Cochrane Back Review Group and extracted the data, resolving disagreements by consensus.
Six randomized controlled trials of reasonable quality were included, all published in English. There is some evidence of pain relief with LLLT compared to sham therapy for subacute and chronic low back pain, and those effects were seen only at short-term and intermediate-term follow-up. Long-term follow-ups were not reported. For pain-related disability, there was no difference between LLLT and the comparison groups. For antero-posterior lumbar range of motion, there is insufficient evidence to determine whether LLLT is effective compared to control at short-term follow-up. In two trials, the relapse rate in the LLLT group was significantly lower than in the control group at six months.
Dr. Kumar’s Take
As someone who operates on the spine every week, I have a deep appreciation for anything that can help people manage back pain without surgery. This Cochrane review is from 2007, and the evidence was still building at that time. The honest reading is narrow: some pain relief against sham in the short and intermediate term, no measurable benefit for pain-related disability, and no side effects reported. The reviewers themselves say the data are insufficient to draw firm conclusions, and I am not going to stretch that into more than it is. The two trials showing a lower relapse rate at six months are the part I find most interesting, because relapse is what my patients actually live with, but two trials is a signal to follow, not a reason to change practice.
The Role of Treatment Parameters
The reviewers called for further methodologically rigorous trials comparing LLLT to other treatments, different lengths of treatment, different wavelengths, and different dosages. They also made the point that comparing different LLLT treatments will be more reasonable once dose calculation methods are harmonized. That is a real obstacle: without a common way to calculate dose, trials that look similar on paper may be delivering very different treatments, which makes pooling them across studies difficult.
Practical Takeaways
- LLLT showed some pain relief compared to sham therapy for subacute and chronic low back pain at short-term and intermediate-term follow-up.
- Long-term follow-ups were not reported in the included trials.
- LLLT made no difference to pain-related disability compared to the comparison groups.
- Two trials found a significantly lower relapse rate in the LLLT group at six months.
- No side effects were reported, but the reviewers concluded the data are insufficient to draw firm conclusions.
FAQs
Why did the Cochrane review say evidence was limited?
Only six randomized controlled trials met the inclusion criteria, and the reviewers judged the body of evidence insufficient to draw firm conclusions. They specifically called for more methodologically rigorous trials looking at different treatments, treatment lengths, wavelengths, and dosages, and noted that comparing LLLT treatments becomes more reasonable once dose calculation methods are harmonized.
Should I try laser therapy before considering back surgery?
For nonspecific low back pain, surgery is rarely the first option. Most conservative care starts with exercise and physical therapy. LLLT sits in that conservative category, and no side effects were reported in this review. That said, this review found pain relief against sham only in the short and intermediate term, and no benefit for pain-related disability, so I would treat it as an optional addition rather than a substitute for anything that works.
What wavelengths and doses work best for back pain?
This review could not answer that. One of its stated objectives was to explore the most effective method of administering LLLT, and the conclusion was that further trials are needed on different wavelengths, different dosages, and different lengths of treatment, with harmonized dose calculation methods so that treatments can be compared.
Bottom Line
This Cochrane review of six randomized controlled trials found some evidence of pain relief with low level laser therapy compared to sham therapy in subacute and chronic low back pain, at short-term and intermediate-term follow-up, with no long-term follow-ups reported and no difference in pain-related disability. Two trials reported a significantly lower relapse rate at six months. No side effects were reported. The authors concluded that there are insufficient data to draw firm conclusions, and that is where I would leave it.
