DYNAMICS OF DOPPLER ULTRASONOGRAPHY DATA FROM ARTERIES OF THE LOWER EXTREMITIES AND BRAIN IN THE COURSE OF STATIC ERGOMETRIC TEST

The paper contains analysis of Doppler ultrasonography data (Doppler US) from the leg and brain arteries of 52 Vietnamese male pilots and 15 Russian male pilots during the static ergometric test (Statoergometre machine). The subjects' age varied between 19 and 27 years. The measured parameters included peak systolic velocity (Vps) and resistive index (RI) of the popliteal (PA) and superficial femoral (SFA) arteries in the right leg, and common carotid artery (CCA) before, during and after testing. Results of the investigation evidenced that static strain in leg muscles during the test causes constriction in a segment distal from the superficial femoral artery confirmed by decreased Vps and increased RI in SFA and increased Vps and stable RI in PA. Under the head-to-pelvis g-loads, the static muscle strain is liable to impede blood pooling in leg muscles. Decreases of CCA Vps and RI due to the static muscle strain in consequence of, probably, vasodilatation in the brain, will be favorable to blood redistribution toward the head at the time of g-load. There was no reliable difference in doppler US data between the Vietnamese and Russian pilots.