RecruitingProcedureEndothelial Dysfunction After SCIThis study plans to learn how endothelial cells, single cell lining of blood vessels may be dysfunctional after a spinal cord injury. Endothelial dysfunction will be measured by the capacity of blood vessels to vasodilate (increase in size) and alter blood flow is lower in adults with a spinal cord injury in comparison to adults without a spinal cord injury. The mechanisms which may alter this function may be critical in reducing the risk of heart attacks and strokes in people with spinal cord injuries.