Efficacy of polarized light therapy for musculoskeletal pain

Abstract

We evaluated the efficacy of polarized Sight therapy for pain attenuation in outpatients with various types of musculoskeletal pain. The patients consisted of 100 with herniated intervertebral disc. 48 cases of myofascial pain syndrome, 36 with sprain and strain, 26 with frozen shoulder, 23 with arthritis, 15 with Raynaud's syndrome, and 15 cases of tendinitis or epicondylitis. Degree of pain was assessed by a visual analogue scale: VAS (0 to 10) before and after polarized light therapy. The polarized light therapy system used had 1800 mW power output and a wavelength range of 600 to 1600 nm. Along with irradiation of trigger and tender points, irradiation was carried out near the stellate ganglion for 5 to 10 min for the upper limbs and near the lumbar sympathetic ganglion for 10 min. The mean VAS before treatment was 8.3 ± 1.7, whereas that after treatment was 3.1 ± 1.9. The difference was significant (P<0.01). Excellent results (full recovery of movement and strength with more than 75% of the VAS improvement rate) were seen in 135 patients (51.3%), and good results (significant improvement of movement and strength with an improvement in the VAS score between 50% and 75%) were obtained in 69 patients (26.2%) Thermographic evaluation revealed increases of regional temperature when the temperature was relatively hypothermic, and decreases when it was relatively hyperthermic. Although some first and second degree burns at the probe site were observed they were transient and no specific treatment was needed. Our results indicate that polarized light therapy is effective in the attenuation of musculoskeletal pain of various origins, as is low reactive-level laser therapy (LLLT). © 1993, International Phototherapy Association. All rights reserved.