Sympathetic-Somatomotor Coupling in Human Spinal Cord Injury

Significance: The long term objective of this study is to improve physical therapy and fitness programs in people with spinal cord injury. The results of the study will demonstrate the importance of matching blood flow to a muscle with exercise of that same muscle. Scientific Objective: The objective of the study is to measure how the body regulates bloodflow to a muscle during exercise. We intend to study these effects by triggering blood flow changes during movement, and measuring bloodflow changes during exercise in people with spinal cord injury. We will also look at the long term effects of different exercise programs on bloodflow during exercise. Study Populations: This study will involve people with partial spinal cord injury and age and sex matched controls without injury. Specific Aims: Aim 1 will be to measure bloodflow during exercise of the legs (below the injury). This aim will examine the control of bloodflow and muscle contractions and how it changes after spinal cord injury. Aim 2 will then look at changes in bloodflow during exercise after training. Three different eight week exercise training programs will be tested including 1) upper body ergometry, 2) treadmill training with exertion level matched to the upper body ergometry and 3) treadmill training with heart rate matched to an initial test of upper body ergometry.