Therapeutic effects of near-infrared radiation on chronic neck pain

Purpose: We aimed to evaluate the therapeutic effects of near-infrared radiation on patients with chronic neck pain using various subjective and objective outcome measures. Methods: Thirty participants with chronic neck pain between 20 years and 65 years of age were divided into two groups. Participants in Group A received near-infrared therapy every day for 1 week and no intervention in the following week. Group B participants received no intervention during the 1st week and near-infrared therapy every day in the following week. Quantitative measures of visual analog scale (VAS), pressure pain threshold (PPT), muscle stiffness, and skin-surface temperature were obtained using specific equipment. Results: Both groups showed significant increases in VAS scores after receiving near-infrared therapy. In most of the sampled muscles, PPT values also increased after receiving near-infrared therapy in both groups. All other outcome measures collected prior to and after therapy displayed nonsignificant differences. Conclusion: Results from this pilot study indicate that near-infrared therapy reduces pain and partially increases PPT. Further investigation of the long-term effects of near-infrared therapy on a larger population is warranted.