What This Review Looked At
Chronic non-specific neck pain is one of the most common reasons adults consult primary care and physiotherapy. It is also one of the most stubborn — exercise helps, manual therapy helps, but the response is partial for many patients and recurrence rates remain high. In 2009 a research team led by Roberta Chow at the University of Sydney published a landmark systematic review and meta-analysis in The Lancet asking a direct, methodologically rigorous question: across the available randomised trials, does low-level laser therapy reduce pain in chronic neck pain — and if so, by how much, and for how long?
The authors searched the major medical databases for randomised controlled trials of LLLT in adults with acute or chronic non-specific neck pain published up to October 2008. Sixteen trials covering 820 patients met the inclusion criteria. The meta-analysis pooled pain reduction outcomes (visual analogue scale) immediately after treatment and at follow-up time points up to 22 weeks, using random-effects models that accounted for variation between trial protocols.
What They Found
Across the pooled trials, low-level laser therapy reduced neck pain by a mean of 19.86 mm on the 100 mm visual analogue scale immediately after treatment compared with placebo. That is a clinically meaningful effect — the threshold for a clinically important difference in pain VAS is generally considered to be around 15-20 mm. The effect held up at medium-term follow-up, with significant pain reduction sustained for up to 22 weeks after treatment.
The result emerged across heterogeneous trials — varying wavelengths (660 nm to 905 nm), dose parameters, treatment frequencies and treatment durations. The fact that a consistent direction and clinically meaningful magnitude of effect appeared despite this protocol variation is one of the stronger forms of evidence that the underlying mechanism is real.
What This Means in Context
Publication in The Lancet matters here. The Lancet does not publish meta-analyses of non-pharmacological pain interventions casually, and the editorial process for this paper was unusually rigorous. The conclusions sit among the strongest evidence-based statements made about LLLT in any clinical area.
The review focuses on short and medium-term pain reduction. It does not by itself establish the optimal protocol for any individual patient, nor does it compare LLLT head-to-head against the conservative-care interventions most patients try first (exercise, manual therapy, NSAIDs). What it does establish is that, where conservative care has not been enough, LLLT is a well-supported addition with a body of randomised evidence behind it.
What It Means for You
If you live with chronic neck pain and the standard approaches have only partly helped, this Lancet meta-analysis is among the most-cited and most-rigorous pieces of evidence supporting low-level light therapy as a meaningful addition. The protocols that worked in the included trials were clinical (administered by a trained operator), and at-home photobiomodulation devices have evolved considerably since 2009 — the clinician helping you manage your neck pain is the right person to discuss which approach fits your situation.
Citation: Chow, R.T., Johnson, M.I., Lopes-Martins, R.A., & Bjordal, J.M. (2009). Efficacy of low-level laser therapy in the management of neck pain: a systematic review and meta-analysis of randomised placebo or active-treatment controlled trials. The Lancet, 374(9705), 1897-1908. PubMed
