The dose-response effects of low level laser therapy on pain and range of motion in patients with lumbar disc protrusion

To assess the effectiveness of low level laser therapy (LLLT) on pain and range of motion (ROM) in patients with lumbar disc protrusion. A sample of convenience of 45 patients randomly assigned to 3 groups (n=15) including: High dose LLLT group (Dose= 40 j/cm2،age=35/886±5/8 mass= 70/4±8/7)، low dose LLLT group (Dose= 7 j/cm2، age=36/13±6/3 mass= 69/3±13/5) and control group (age=36/53±4/8; mass=69/16±8/33). All Patients in each group treated with LLLT 3 times per week to 15 sessions. Pain and ROM were measured pre and post treatment with visual analogue scale and clinical tests respectively. Between group comparisons of all data were performed using ANOVA (α<0. 05) Most patients in this study had pain during sitting. There were not significant differences in gender (p=0/145)، pain during sitting (p=0/432) and sport activities (p=0/132) between 3 groups. Although the mean values of pain intensity (p=0/281)، flexion (p=0/223)، extension (p=0/906)، right (p=0/211) and left (p=0/503) lateral flexion، rigth (p=0/205) and left (p=0/653) rotation variables were not significant between these groups before treatment. Furthermore، pain (p= 0/001)، lumbar flexion (p= 0/011) and lumbar extension (p=0/045) showed significant differences after treatment that was related to low dosage laser therapy based on post-hoc analysis. low dosage LLLT may be effective in decreasing pain and improving ROM in patients with lumbar disc protrusion.