LOWER-EXTREMITY BLOOD-FLOW AND RESPONSES TO OCCLUSION ISCHEMIA DIFFERIN EXERCISE-TRAINED AND SEDENTARY TETRAPLEGIC PERSONS

Objective: To test whether lower extremity blood flow and hyperemic re sponses to vascular occlusion differ among electrically stimulated exe rcise trained and sedentary tetraplegic persons and subjects without t etraplegia (control). Design: Blinded cross-sectional comparison, cont rol group. Setting: Academic medical center. Participants: Ten sedenta ry tetraplegic men, 10 tetraplegic persons previously habituated to el ectrically stimulated cycling exercise for 0.4 to 7 years, and 10 nond isabled controls. Outcome Measures: Subjects underwent quantitative Do ppler ultrasound examination of the common femoral artery (CFA). End-d iastolic arterial images and arterial flow-velocity profiles obtained at rest and following five minutes of suprasystolic thigh occlusion we re computer digitized for analysis of heart rate (HR), CFA peak systol ic velocity (PSV), CFA cross-sectional area (CSA), how velocity integr al (FVI), and computed CFA inflow volume (IV). Results: No group main effects were observed for resting HR or FVI. At rest, trained tetraple gic men had 14.9% greater PSV, 29.8% larger CSA, and 51.3% greater IV (p values <.05) than sedentary tetraplegic subjects. Resting PSV and I V of the trained subjects did not differ from controls, although CSA w as smaller than controls (p <.05). Following occlusion, PSV, CSA, and IV averaged 16.5%, 33.4%, and 65.1% greater for trained tetraplegics p ersons, respectively, than sedentary tetraplegic subjects (p values <. 05). Only CSA differed between the control and the trained groups (p < .05). Conclusion: Tetraplegic persons conditioned by electrically stim ulated cycling have greater lower extremity blood how and hyperemic re sponses to occlusion than do their sedentary counterparts. (C) 1996 by the American Congress of Rehabilitation Medicine and the American Aca demy of Physical Medicine and Rehabilitation.