Background and Aim : Chronic non-specific low back pain is one of the important health problem in military and different factors have been reported in its emergence. The aim of this study is to determine the association between low back pain and education level, Body Mass Index (BMI), exercise, smoking status ,work status and bad postures in military men.

Materials and Methods : In this non-experimental case-control study, 92 subjects (mean age= 29.16 year, SD= 8.55 year) with chronic non-specific low back pain and 93 subjects (mean age= 26.80 year, SD=9.22 year) without low back pain were selected by simple non-probability method from military centers in Tehran. Evaluation tools of this study included a self-administrated questionnaire, weighting scale and metal tape measure.

Results : According to the results of bivariate logistic regression, risk factors of exercise (P= 0.003), smoking status (P= 0.042), grade of BMI (P= 0.034), bad posture grades including heavy objects lifting movements (P= 0.007), bending movements (P= 0.003), rotating movements from the lumbar (P= 0.011), carrying bulky objects (P= 0.034), carrying heavy objects (P= 0.05) and working in squatting position (P= 0.005) had a significant association with low back pain. Job status (P= 0.999), education level (P= 0.056) and bad postures grades movements like wringing clothes (P= 0.958) had not a significant association with low back pain.

Conclusion : Doing regular exercise and having normal BMI decrease the risk of suffering from low back pain in the military while smoking and doing injurious physical activities during work (lifting heavy objects, bending movements and rotating from the lumbar, carrying bulky and heavy objects, and working in squatting position for a long time) increase the risk of suffering from low back pain.

Key Words : Chronic non-specific low back pain, Military forces, Biomechanical risk factors, Exercise