Investigation of Efficacy of Botulinum Toxin A (Dysport) in Chronic Low Back Pain

Inclusion Criteria: * Age 18-80, all ethnic groups, races, both sexes. * Diagnosis of chronic low back pain (longer than 3 months). * Pain of moderate to severe intensity (VAS 4 or higher). * Subjects who are able to read, speak, and understand English. Exclusion Criteria: Existing significant acute medical condition (i.e. cardiovascular, endocrine, hematologic, neoplastic, infectious, or autoimmune disorders). * Hypersensitivity to any botulinum toxin product or is recipient * Allergy to albumin. Lactose or cow milk protein * Infection in the proposed injection site. * Pregnancy or planned pregnancy (determined by urine pregnancy test). The women of childbearing age should use a reliable mode of contraception during the study period (abstinence, etc). * Active breast feeding. * Enrollment in any clinical trial (currently or within the past 3 months) in which treatments are imposed by a protocol. * Patients taking high doses of aminoglycosides or other drugs affecting the function of neuromuscular junction (anticholinergics , muscle relaxants) * Subjects who are younger than 18 years of age. * Neuromuscular-junction disorders and motor neuron disease such as Amyotrophic Lateral Sclerosis. * Evidence of acute pathology on neuro-imaging. * Axis I diagnosis determined by a neurologist or psychiatrist. * Anesthetic medications within two weeks and corticosteroid injections within 4 weeks of enrollment. * Received botulinum toxin injections in the past 3 months. * History of low back surgery , evidence of acute disc or severe lumbar stenosis in MRI