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

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. 40 subjects with low back pain entered the study. Patients were aged between 20-70 and their pain severity scale was 3-10 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 (250- 1000 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 12 sessions of laser (160 mw) and control group took 12 sessions of sham laser (the same laser instrument in off status). An infrared laser GaAlAs, wave length 808 nm, power 160 mw and spot size 1 cm 2 , power density 0.16 J/cm 2 , 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 40 subjects who included the study 6 were excluded and 34 entered the analysis. There was significant improvement in pain (p<0.001 at both groups), functional status (Case group: p<0.001, control group: p=0.004) and spinal ROM (Case group: p<0.001 and control group: p= 0.007) in both groups at the end of first month, but these gains persisted to three months only in case group (p<0.001). Regarding spinal tenderness, it was disappeared in 89.47% of patients in true laser group at the end of one month but remained unchanged in 73.33% 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.