Fig. 1.

Schematic of forearm exercise model. Brachial artery blood velocity was measured (via Doppler ultrasound) proximal to the balloon. The configuration of the balloon upstream from the lumen of the introducer allowed measurement of the brachial arterial pressure (BAP) distal to the balloon that was perfusing the contracting forearm muscles. Rhythmic forearm exercise was performed with a hand grip device by lifting a weight (10% and 20% of maximal voluntary contraction) 4–5 cm over a pulley system at a duty cycle of 1-s contraction and 2-s relaxation (20 contractions/min).