Evaluation of the Efficacy and Safety of Herbal Medicine for Treating Work-related Chronic Low Back Pain

Inclusion Criteria: * Inpatients with chief complaint of low back pain in oriental rehabilitation medical center * Age 19 - 65 * Workplace Vulnerable populations(hospital workers, office worker, blue collar workers, transit workers) * Patients must include all of the following symptoms: * Those who have 4 \~7 cm of VAS pain score; * Those who has classified as 'at risk non-complier' or 'pain complaints' by KOSHA questionnaire * Ability to have normal communication * Ability to give informed consent Exclusion Criteria: 1. Patients with pain duration of 3 months or less 2. Patients with progressive neurologic deficit or severe neurologic symptoms by SLR test 3. Patients diagnosed with serious pathology(s) which may cause low back pain (e.g. spinal metastasis of tumor(s), acute fracture, etc) 4. Patients with spondylolisthesis or spondylolysis(diagnosed with grade II or higher level) 5. Patients currently taking steroids, immunosuppressants, medicine for mental illness or other medication(s) that may interfere with study results 6. Patients with history of spinal surgery 7. Patients with more severe pain than pain caused by low back pain 8. Those who do not (cannot) abide by treatment and follow up due to the mental illness such as behavior disorder, depression, anxiety neurosis etc. 9. Patients with history of Medical Malpractice Case 10. Patients with treatment history of low back pain within 1 month either KM or WM 11. Patients participating in other clinical studies within 3 months 12. Pregnant patients or patients with plans of pregnancy or lactating patients 13. Patients disagree to sign the informed consent form 14. Patients deemed unsuitable for participating the trial by the researchers