Botulinum Toxin A for the Treatment of Chronic Lumbar Back Pain

Inclusion Criteria: * Active duty military, retired military or other DoD healthcare beneficiaries of either sex, aged 18-70 years, with symptoms of chronic back pain. * A clear history of an identifiable muscle strain or back trauma preceding the chronic pain. * Current pain duration \> 6 months. * MRI of the affected spine area to define potential or serious pathology as per standard of care. * Written informed consent and written authorization for use or release of health and research study information. * Normal neurological examination without evidence of radiculopathy. * VAS score minimum of 4 cm or reaches an average of 4 cm out of 10 cm at least 4 days a week, at time of entry into study * Ability to follow study instructions and likely to complete all required visits. * Negative urine pregnancy test prior to the administration of study medication (for females of childbearing potential) (if applicable). Exclusion Criteria: * Age less than 18 or greater than 70 years * Concomitant use of amino glycoside antibiotics, curare-like agents, or other agents that might interfere with neuromuscular function. * Any medical condition that may put the subject at increased risk with exposure to Botulinum Toxin A (Botox®), including diagnosed myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis/motor neuron disease, neuropathy, renal stones, or any other disorder that might interfere with neuromuscular function or produce a similar type of back pain. * Females who are pregnant, breast-feeding, or planning a pregnancy during the study or who think that they may be pregnant at the start of the study, or females of childbearing potential who are unable or unwilling to use a reliable form of contraception during the study. * Known allergy or sensitivity to any of the components in the study medication. * Evidence of recent alcohol or substance abuse. * Known, uncontrolled systemic disease. * Participation in the 30 days preceding enrollment or during the duration of this study in another investigational drug or device study. * Any condition or situation that, in the investigator's opinion, may put the subject at significant risk, confound the study results, or interfere significantly with the subject's participation in the study. * Significant Axis I or Axis II diagnosis determined by a neurologist or psychiatrist in the 6 months prior to entry into study * Duration of back pain \< 6 months. * Thoracic or cervical spine pain in the absence of low …