Femoral Artery Blood Flow and Microcirculatory Perfusion During Acute, Low-Level Functional Electrical Stimulation in Spinal Cord Injury

Objective Functional electrical stimulation (FES) may help to reduce the risk of developing macrovascular and microvascular complications in people with spinal cord injury. Low-intensity FES has significant clinical potential because this can be applied continuously throughout the day. This study examines the acute effects of low-intensity FES using wearable clothing garment on vascular blood flow and oxygen consumption in people with spinal cord injury. Design This was a cross-sectional observation study. Methods Eight participants with a motor complete spinal cord injury received four 3-min unilateral FES to the gluteal and hamstring muscles. Skin and deep femoral artery blood flow and oxygen consumption were measured at baseline and during each bout of stimulation. Results Femoral artery blood flow increased by 18.1% with the application of FES (P = 0.02). Moreover, femoral artery blood flow increased further during each subsequent block of FES (P = 0.004). Skin perfusion did not change during an individual block of stimulation (P = 0.66). Skin perfusion progressively increased with each subsequent bout (P < 0.001). There was no change in femoral or skin perfusion across time in the nonstimulated leg (all P > 0.05). Conclusion Low-intensity FES acutely increased blood flow during stimulation, with a progressive increase across subsequent FES bouts. These observations suggest that continuous, low-intensity FES may represent a practical and effective strategy to improve perfusion and reduce the risk of vascular complications.