E-STIM Trial: Comparing the Efficacy of the Empi Select TENS to a Control for the Treatment of Chronic Lower Back Pain

Inclusion Criteria:

• Subjects must be 18-65 years of age.

• Subjects must have reported low back pain of at least 3 months duration.

• Subjects must report a low back pain score of 4 or greater on the 0-10 point NumericalRating Scale (NRS) for average daily pain.

• Subjects must have been on a stabilized analgesic medication regimen for 3 months orgreater.

• Subjects must be willing to discontinue use of all rescue pain medications for theduration of the trial (all PRN medications for breakthrough pain), except for OTC oralacetaminophen (up to 4 grams per day).

• Subjects must be willing to refrain from starting any new lower back pain treatmentsfor the duration of the trial.

• Subjects must be willing and able to comply with all follow-up procedures (includingcompletion of the daily diary) and return for scheduled follow- up visits.

• Female subjects must be post-menopausal for at least 1 year, surgically sterile orwilling to take a pregnancy test which must be negative prior to study enrollment.

• Subjects must be willing and able to provide written informed consent and HIPAAauthorization prior to enrollment into the study.

Exclusion Criteria:

• Subjects that have a demand type pacemaker or defibrillator.

• Subjects that have had previous experience with electrotherapy.

• Subjects that have had any failed back surgeries.

• Subjects that have spinal stenosis which contributes to, or is the cause of lower backpain.

• Subjects that have sciatica (lower back pain with radicular symptoms).

• Subjects that have cauda equina syndrome.

• Subjects that have fibromyalgia.

• Subjects that have pain secondary to cancer.

• Subjects who have cancer in the same anatomical location as their back pain.

• Subjects that have any sensory deprivation or diagnosis of shingles or post- herpeticneuralgia (specifically in the mid-trunk region).

• Subjects that have planned surgeries during the study period.

• Subjects that have a history of alcohol or substance abuse in the last 5 years.

• Subjects on psychoactive medication(s) that:

1. have had a change in dose or a change in medication type during the 3 monthsprior to screening, or

2. are expected to require a change in dose, or a new medication during the study.

• Subjects that are seeking worker's compensation or any other legal claims.

• Subjects that are pregnant or plan to become pregnant during the study period.