Effect of TENS Versus Placebo on Walking Capacity in Patients With Lumbar Spinal Stenosis: A Protocol for a Randomized Controlled Trial

BACKGROUND: Lumbar spinal stenosis (LSS) is a growing health problem and a leading cause of disability and loss of independence in older adults. It is usually caused by age-related degenerative narrowing of the spinal canals leading to compression and ischemia of the spinal nerves and symptoms of neurogenic claudication. Limited walking ability is the dominant functional impairment caused by LSS. Animal studies suggest increased blood flow to the spinal nerves and spinal cord with superficial paraspinal electrical stimulation. The purpose of this study is to assess the effectiveness of paraspinal transcutaneous electrical nerve stimulation (TENS) applied while walking on walking ability in patients with LSS. METHODS/DESIGN: We propose to conduct a 2-arm double-blinded (participant and assessor) randomized controlled trial. We will recruit individuals who have limited walking ability due to degenerative LSS from hospital specialists, community physicians, and chiropractors located in the city of Toronto, Canada. Eligible consenting participants will be randomly assigned to either paraspinal TENS or placebo paraspinal TENS applied while walking. The primary outcome will be walking distance measured during a single self-paced walking test. We will calculate the differences in proportions among participants in both groups who achieve at least a 30% improvement in walking distance from baseline using Pearson χ(2) test with 95% confidence intervals. DISCUSSION: Effective nonoperative interventions for LSS are unknown. Interventions that can improve blood flow to the spinal nerves while walking may increase walking ability in this population. Transcutaneous electrical nerve stimulation is a low-cost intervention that may have the potential to achieve this objective. To our knowledge, this study will be the first clinical trial to assess the effects of TENS on walking ability of patients with LSS. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02592642