Passive Leg Movements and Passive Cycling Do Not Alter Arterial Leg Blood Flow in Subjects With Spinal Cord Injury

Abstract

Subjects with a spinal cord injury (SCI) are at increased risk for cardiovascular disease-related secondary complications, such as pressure ulcers and attenuated wound healing. It has been suggested that passive exercise enhances blood flow via mechanical pump effects or reflex activation. The purpose of this study was to assess the effects of passive leg movements and passive cycling on the arterial circulation in subjects with SCI. Eight men with motor complete SCI and 8 male control subjects participated. Echo Doppler measurements were obtained to measure leg blood flow at rest, during and after 10 minutes of standardized passive leg movements, and during and after 20 minutes of passive leg cycling. Blood pressure was measured continuously, and total vascular resistance and leg vascular resistance were calculated. In both groups, no changes in leg blood flow, vascular resistance, or blood pressure were observed during or after the 2 interventions. The results of the study demonstrate that passive leg movements and passive cycling do not alter the arterial peripheral circulation in subjects with SCI or control subjects. Although the results do not support the use of passive movements or exercise for the prevention of cardiovascular disease-related secondary complications, physical therapists should not be dissuaded from using these techniques to address musculoskeletal concerns.