Mechanisms and Efficacy of High-Intensity Variable Training in Patients with Incomplete SCI
Abstract
Seeking methods to maximize recovery of walking ability following motor incomplete spinal cord injury (iSCI) has been an area of intense investigation in the past few decades. While the use of cell-based and regenerative strategies are rigorously studied in the laboratory setting, the timeline for the successful translation of these interventions to people with SCI remains unclear. Previous intervention strategies have focused primarily on use of physical rehabilitation, with adjunctive interventions such as robotic devices, and surface neuromuscular or epidural spinal stimulation, although the success of these techniques is not certain. While selected strategies may be promising, the availability and applicability of these techniques to a larger population of patients with iSCI is not clear, as specific equipment or procedures may be costly and/or invasive. In contrast, specific training interventions that have been recognized for decades to improve locomotor performance in other disciplines may be able to elicit substantial gains in locomotor function in patients with iSCI. More directly, we contend that specific training parameters, including the type (specificity), amount, and intensity of task practice, are critical to mobility outcomes, consistent with principles of motor learning and exercise physiology applied in individuals without injury. Previous studies support the notion that task-specific (i.e., stepping) practice may improve locomotor performance in patients with neurological injury and can be applied on a treadmill or overground. However, stepping practice alone is insufficient, as specific stepping paradigms that reduce patient engagement and volitional activity (i.e., robotic-assisted stepping) results in minimal improvements in walking outcomes. Accordingly, the intensity of locomotor practice, defined as power output or workload and estimated using cardiopulmonary measures, can be a significant variable that enhances locomotor performance, as evaluated in patients with stroke. However, the role of intensity of practice has not been well studied in patients with incomplete SCI. Our primary objectives are to assess the influence of locomotor training intensity on walking outcomes in patients with motor iSCI. We intend to investigate the effects of high- versus low-intensity training of walking practice of variable stepping tasks and in multiple environments (overground, treadmill, stairs) on locomotor outcomes in ambulatory patients at least 1 year following motor iSCI. We will primarily focus on specific measures of walking performance, such as peak walking speed overground and on a treadmill, but also measures of motor coordination, impairments in strength and endurance, and cardiopulmonary capacity and efficiency. These secondary measures will also help researchers identify key physiological processes that contribute to improved walking performance such that future studies may harness these changes. Nonetheless, the potential benefit to patients with iSCI on walking function in the home and community are critical. Improvements in walking function are the primary determinant of community mobility and are related to measures of perceived quality of life and participation. The potential benefits of high- versus low-intensity training will be assessed, as well as potential risks, including increases in fatigue, dizziness or lightheadedness associated with exercise, muscle/joint pain or damage with repeated lower extremity loading during walking, and measures of cardiovascular regulation. We anticipate the benefits of higher intensity exercise will outweigh the potential risks to allow application of such training. If successful, application of high-intensity training in patients with iSCI represents an easily modifiable training parameter that can be readily applied in multiple clinical environments without substantial additional costs or equipment. While the focus of this application may be on patien
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 29, 2018
- Source ID
- W81XWH1810796
Entities
People
- Thomas Hornby
Organizations
- Indiana University – Purdue University Indianapolis
- United States Army