Evaluation of the Therapeutic Effect of Low Level Laser in Controlling Low Back Pain: A Randomized Controlled Trial

Abstract Introduction: Low back pain is a very common musculoskeletal disorder. The big burden of disease necessitates investigating a more effective modality of treatments with more persistence and also less side effects. Low power laser has been proved as a pain reducing modality, but there are lack of studies comparing it with other treatments and also among the Iranian race and society. The purpose of this study was to evaluate the effect of low level laser in patients with low back pain.Methods: Our study was a single blind, randomized controlled trial. ۴۰ subjects with low back pain entered the study. Patients were aged between ۲۰-۷۰ and their pain severity scale was ۳-۱۰ according to visual analogue scale of pain (VAS).They were randomly assigned in two groups of case (true laser) and control (sham laser). Naproxen was prescribed with a free dose (۲۵۰- ۱۰۰۰ mg/daily) in both groups. We evaluated patients’ subjective pain, functional status (using Roland Morris disability questionnaire), spinal ROM and spinal tenderness at the basic time, one and three months post- treatment. True laser group received ۱۲ sessions of laser (۱۶۰ mw) and control group took ۱۲ sessions of sham laser (the same laser instrument in off status). An infrared laser GaAlAs, wave length ۸۰۸ nm, power ۱۶۰ mw and spot size ۱ cm۲, power density ۰.۱۶ J/cm۲, in continuous mode was used in treatment. We applied laser to articular space of vertebral column, adjacent paravertebral points, pain radiating areas and tender points and also pain-controlling acupuncture points.Results: From ۴۰ subjects who included the study ۶ were excluded and ۳۴ entered the analysis. There was significant improvement in pain (p<۰.۰۰۱ at both groups), functional status (Case group: p<۰.۰۰۱, control group: p=۰.۰۰۴) and spinal ROM (Case group: p<۰.۰۰۱ and control group: p= ۰.۰۰۷) in both groups at the end of first month, but these gains persisted to three months only in case group (p<۰.۰۰۱). Regarding spinal tenderness, it was disappeared in ۸۹.۴۷% of patients in true laser group at the end of one month but remained unchanged in ۷۳.۳۳% of subjects of sham laser group.Conclusion: We concluded that laser therapy (in combination with NSAIDs) is an effective and long-lasting therapeutic strategy in relief from LBP without any significant side. Keywords: Low Back Pain Low-level laser therapy GaAlAs laser