ACUTE EFFECTS OF THERAPEUTIC ULTRASOUND DELIVERED AT VARYING PARAMETERS ON THE BLOOD-FLOW VELOCITY IN A MUSCULAR DISTRIBUTION ARTERY

Therapeutic modalities that alter hemodynamic parameters may have a dr amatic impact on the viability of living tissues. The purpose of the c urrent study was to investigate the response of blood low velocity to various treatment parameters of therapeutic ultrasound. Twenty healthy volunteers attended six randomly selected 15-minute treatment session s of the following parameters: Tx-1 = 1.0 MHz at 1.5 W/cm(2), Tx-2 = 1 .0 MHz at 1.0 W/cm(2); Tx-3 = 3.0 MHz at 1.2 W/cm(2); Tx-4 = 3.0 MHz a t 1.0 W/cm(2) Tx-5 = sham; and Tx-6 = control. Ultrasound was applied to a circular area over the triceps surae muscle mass. Blood flow velo city in the popliteal artery was assessed after 5, 10, and 15 minutes of ultrasound and at two posttreatment intervals via a dual frequency bidirectional ultrasound Doppler. A two-factor analysis of variance (p less than or equal to 0.05) with repealed measures For treatment and time was performed on the data. Groups Tx-1 and Tx-2 showed significan t increases in blood flow velocity when compared with the control and all other groups. The sham group showed significant increases in blood flow velocity when compared with the control group. Groups Tx-3 and T x-4 showed no significant change when compared with the sham condition . The results of the current study indicate that 1.0 MHz ultrasound de livered at 1.0 and 1.5 W/cm(2) to the triceps surae musculature as des cribed in the present study can increase the blood flow velocity in th e popliteal artery.