The Effectiveness of Wet Cupping on Persistent Non-specific Low Back Pain

Inclusion Criteria: * Patients who have had non-specific low back pains at least 12 weeks now. Exclusion Criteria: * Patients who have low back pain due to specific and known etiological causes (infection, tumor, osteoporosis, ankylosing spondylitis, fracture, inflammatory process, radicular syndrome, cauda equinal syndrome). * Patients who are inappropriate to the wet cupping treatment. * AIDS, Active Hepatitis, Tuberculosis, Syphilis * Patients who regularly take anticoagulants, antiplatelet drugs * Anemia, thrombocytopenia * Hemorrhagic disease like hemophilia * Diabetes * Severe cardiovascular disease * Kidney diseases (renal failure, chronic renal disease) * Patients who have experiences of wet cupping treatment during last 3 months. * Patients who have had treatment for low back pain during last 2 weeks. * Patients who are in pregnancy or have plan to conception. * Patients who have vertebra surgery or have plan of surgery. * Patients who are inappropriate to join this trial judged by the radiologists or specialists.