Short-term therapeutic effects of 890-nanometer light therapy for chronic low back pain: A double-blind randomized placebo-controlled study

We conducted a double-blind randomized placebo-controlled study to investigate the effects of short-term 890-nm light therapy in patients with chronic low back pain in a rehabilitation clinic. Thirty-eight women and 22 men with chronic low back pain (mean age, 60.3 years; range, 32-80 years) received 40-min sessions of hot-pack therapy combined with active or placebo 890-nm light therapy (wavelength=890 nm, radiant power output=6.24 W, power density=34.7 mW/cm² for 40 min, total energy=83.2 J/cm²) over the lower back three times weekly for 2 weeks. Participants were assessed before and after treatment by using a range of motion measurements, a visual analog scale evaluation of pain, the Multidimensional Fatigue Inventory, the Biodex Stability System, the Fear-Avoidance Beliefs Questionnaire, repeated chair-rising times, the Frenchay Activity Index, the Oswestry Disability Questionnaire (ODQ), and the Osteoarthritis Quality of Life Questionnaire. The severity of disability based on the ODQ score was used as the primary clinical outcome measurement. Compared to the baseline measurements, participants in the treatment group reported significant reductions in fear-avoidance beliefs regarding physical activity (P=0.040) and work (P=0.007) and in the severity of disability (P=0.021). Treatment with hot-pack therapy and 890-nm light therapy was associated with reductions in the severity of disability and fear avoidance beliefs in patients with chronic low back pain.