Degenerative lumbar spinal stenosis (DLSS) or osteoarthritis of the spine is a leading cause of pain, disability, and loss of independence in older adults. It is a chronic disease caused by age related degenerative narrowing (stenosis) of the spinal canal that can lead to compression and ischemia of the spinal nerves (neuro-ischemia). The clinical syndrome of DLSS is known as neurogenic claudication. It is characterized by bilateral or unilateral buttock and/or lower extremity pain, heaviness, numbness, tingling or weakness, precipitated by walking and standing and relieved by sitting and bending forward. Limited walking ability is the dominant functional impairment caused by DLSS. Those afflicted have greater walking limitations than individuals with knee or hip osteoarthritis and greater functional limitations than those with congestive heart failure, chronic obstructive lung disease or systemic lupus erythematosus. Inability to walk among individuals with DLSS leads to a sedentary lifestyle and a progressive decline in health status. The prevalence and economic burden of DLSS is growing exponentially due to the aging population. Although DLSS is the most common reason for spine surgery in individuals over the age of 65, only very few DLSS patients receive surgery. The vast majority of individuals with DLSS receive non-surgical care. However, what constitutes effective non-surgical care is unknown. Self-management strategies may be a practical and effective means to improve walking ability, functional status, and quality of life in this chronic arthritic and often progressive condition. The investigators have conducted two systematic reviews of the literature, one assessing the effectiveness of non-surgical treatments for neurogenic claudication which included randomized controlled trials (RCTs) assessing improvements in pain, disability, quality of life or global improvement; the other evaluated the effectiveness of surgical or non-surgical interventions and included only RCTs that assessed improved walking ability. the investigators learned from these reviews that the evidence for interventions that improve outcomes including walking ability in neurogenic claudication due to DLSS is lacking. The evidence published thus far on this topic has been of low or of very low quality, prohibiting the formulation of evidence-based recommendations for clinical practice. Moreover, the investigators identified no RCTs that examined a self-management approach to the treatment of DLSS.
In addition to the structural arthritic changes causing narrowing of the spinal canal, DLSS has an important dynamic component. The volume of the spinal canal and degree of epidural pressure and ischemia of the spinal nerves can change depending on spinal posture. Both lumbar flexion (stooping forward), and sitting increase the diameter of the canal and reduce spinal nerve ischemia, and correspond with a reduction or elimination of lower extremity symptoms. Conversely, lumbar extension or increasing the lumbar lordosis (which occurs when standing) reduces the diameter of the spinal canal and increases spinal nerve ischemia, and corresponds with increased lower extremity symptoms. The ability to reduce symptoms of DLSS by changing spinal posture/structural alignment and/or increasing blood flow to the spinal nerve provides potential mechanisms for developing interventions to improve symptoms and walking ability.
First, the investigators have designed and implemented a novel six week self-management training program for DLSS over the past 3 years at the Spinal Stenosis Clinic at the Rebecca MacDonald Centre for Arthritis and Auto-immune Diseases at Mount Sinai Hospital (MSH). The goal of the training program is to provide patients with the knowledge, skills, self-confidence, and physical capacity to manage their symptoms and maximize their function. The program is multi-modal, tailored and directed to the structural, functional, physiological and psychosocial consequences of DLSS. Particular emphasis is placed on exercise instruction to build core and lower extremity strength and enable individuals to achieve optimal posture during standing and walking.
There are numerous human studies demonstrating significant reduction in laboratory induced ischemic pain in the lower and upper extremities with paraspinal TENS compared to placebo TENS. Moreover, there is low quality evidence from one case series suggesting that electrical stimulation may be effective for the management of neurogenic claudication. Higher quality studies are needed to assess whether paraspinal TENS applied while walking improves walking ability, as this could be an innovative, convenient, and inexpensive self-management strategy for DLSS patients.
Finally, the investigators have designed a prototype spinal stenosis belt with the Ontario College of Art and Design. The belt is designed as garment that will snugly fit over the sacrum and pelvic girdle with a pump that place pressure over the sacrum with the aim to reduce the lumbar lordosis and maximize the spinal canal diameter when walking. The investigators hypothesize the belt will reduce the lumbar lordosis and alleviate epidural pressure and neuro-ischemia while standing and walking. The investigators identified two preliminary studies evaluating back belts, supports or braces for DLSS, none of which were RCTs. These studies found significant improvements in walking distance with the use of a back corset; however both studies had a high risk of bias.
OBJECTIVES AND HYPOTHESES The overall goal of this study is to assess the effectiveness of four self-management strategies in improving walking ability among patients with DLSS. The investigators primary objective is to compare the effectiveness of a comprehensive six week self-management training program that includes a patient instructional workbook, video and pedometer to a patient workbook, video and pedometer alone. The investigators secondary objectives are: 1) to compare the change in walking capacity from baseline when using superficially applied para-spinal TENS versus placebo para-spinal TENS applied during walking and 2) to compare the change in walking capacity from baseline while wearing a novel spinal stenosis belt to the use of a sham spinal stenosis belt while walking. The investigators hypothesize that the self-management training program with workbook, video and pedometer will be more effective in improving walking capacity and functional outcomes than the use of a workbook, video and pedometer alone. Furthermore, the investigators hypothesize that para-spinal TENS or the novel spinal stenosis belt used while walking will be more effective in improving walking capacity than placebo TENS or a sham spinal stenosis belt, respectively.
