Laser acupuncture for chronic non-specific low back pain: a controlled clinical trial

Chronic nonspecific low back pain represents a significant public health problem, affecting millions of people worldwide and causing important limitations in quality of life. This condition is characterized by persistent pain in the lumbar region for more than three months, without a specific identifiable cause such as disc herniation or nerve compression. Among the various therapeutic options available, traditional needle acupuncture has already demonstrated scientific evidence of efficacy, but a more recent modality has gained popularity: laser acupuncture. This technique consists of applying low-power laser at the same points used in traditional acupuncture, offering a noninvasive and painless alternative for patients who prefer to avoid the use of needles.

The primary objective of this study was to determine whether laser acupuncture is more effective than a simulated treatment (placebo) for reducing pain and disability in adults with chronic nonspecific low back pain. The methodology employed was a randomized, double-blind clinical trial, in which neither the patients nor the professional applying the treatment knew which device was actually functioning. One hundred participants were recruited through advertisements in local newspapers and medical clinics, all with low back pain for at least three months. The equipment used was a low-power infrared laser that emitted 830 nm wavelength and 10 mW of power, applied for 20 seconds at each point (equivalent to 0.2 J of energy).

The control group received the same procedure but with the laser turned off, with both devices emitting a red light to maintain study blinding. Each participant received between five and ten weekly treatment sessions, with follow-up at six weeks and six months after completion.

The main results showed that, although there was significant improvement in both pain and functional disability in both groups at the end of treatment, no statistically significant difference was found between the group receiving real laser and the placebo group. The mean pain reduction was approximately 40% at the end of treatment and 30% during follow-up, remaining stable in both the short term (six weeks) and the medium term (six months). As for functional disability, there was a 20% reduction that was maintained during the follow-up period. Psychological aspects such as depression and stress also improved significantly in both groups, but again without difference between real and placebo laser.

During the treatment period, a small reduction in the use of analgesic medications was observed in the group receiving real laser, but this difference disappeared in subsequent follow-up. Adverse effects were minimal, limited mainly to small temporary exacerbations of pain, which occurred equally in both groups.

The clinical implications of these results are important for both patients and health care professionals. For patients, the study suggests that laser acupuncture, at least at the dosage tested, does not offer specific benefits superior to the placebo effect, although the treatment as a whole was beneficial for both groups. This means that the improvement observed may be related to other factors of care, such as the individualized attention of the therapist, the detailed evaluation process, the guidance on exercises provided during treatment, or even the effect of the physical pressure exerted during the location of acupuncture points. For professionals, these findings raise questions about the cost-benefit of laser acupuncture as an investment in specific equipment, suggesting that other aspects of comprehensive care may be equally important.

However, it is crucial to understand that this result does not completely disqualify the technique, but rather indicates the need for more research to determine more effective protocols.

The study has some important limitations that should be considered when interpreting the results. First, only one specific dosage of laser was tested (0.2 J per point), while the literature suggests that different doses may produce different results. Some international guidelines recommend much higher doses, reaching 8 J per point, which could completely alter the results. Second, all treatments were performed by a single professional, which may limit the generalizability of the findings to other therapists or clinical settings.

Third, despite careful randomization, some important differences occurred between groups at baseline, especially related to prior use of analgesic medications and previous acupuncture treatments, which may have influenced the results. Finally, the process of point location itself, which involved palpation and skin marking, may have created an acupressure effect that benefited both groups equally. The researchers recommend that future studies investigate different energy dosages, use more rigorous inclusion criteria, and consider ways to minimize secondary effects not specifically related to the laser. Although this study did not demonstrate superiority of laser acupuncture over placebo, it represents an important contribution to the scientific understanding of this therapeutic modality, offering a solid basis for the development of more refined future research.