Abstract
This study evaluated the morphological changes of the lower limb and associated hemodynamic responses to different lower-body compression pressures (COMPs) in physically active, healthy individuals at rest. Each of the 32 participants underwent three trials with three different degrees of lower-body compression applied: “Low” (2.2±1.4 mmHg), “Medium” (12.9±3.9 mmHg), and “High” (28.8±8.3 mmHg). In each COMP, a cross-sectional area of leg muscles (CSAmuscle), subcutaneous fat (CSAfat), superficial vessels (SupV), deep arteries (DA), and deep veins (DV) at the calf, knee, and thigh levels were measured using magnetic resonance imaging (MRI). Additionally, blood pressure (BP), heart rate (HR), cardiac output (CO), stroke volume (SV), and systemic vascular resistance (SVR) were measured using Doppler ultrasound (USCOM®). With High COMP, calf CSAmuscle and SupV were smaller (p<0.01), whereas DA and DV were larger (p<0.05). Calf CSAfat, however, was similar among all COMPs. There were no major changes in CSAmuscle and CSAfat at knee and thigh levels. CO (3.2±0.9 L/min) and SV (51.9±16.4 mL) were higher (p<0.05) only with High COMP, but other hemodynamic variables showed no significant changes across different COMPs. The High COMP at the lower limb induces leg morphological changes and increases associated hemodynamic responses of physically active healthy individuals at rest.
Key words
stroke volume - cardiac output - heart rate - blood vessels - MRI - ultrasound
