Blood pressure in the great toe with simulated occlusion of the dorsalis pedis artery.

Blood pressure was measured in both great toes using strain-gauge plethysmography in 100 healthy persons aged 18 to 43 before and during successive compression of the dorsalis pedis artery, the posterior tibial artery, and both arteries at the same time. In 54 (27 percent) of 200 feet, successive compression of the dorsalis pedis and the posterior tibial arteries produced no decrease in pressure in the great toe. In 47 of the feet, toe pressure decreased significantly only after compression of the posterior tibial artery, and in 65 of the feet toe pressure decreased significantly only after compression of the dorsalis pedis artery. In 34 of the feet, toe pressure decreased significantly after compression of each of the arteries. Thus in 99 (50 percent) of 200 feet, compression of the dorsalis pedis artery decreased the pressure in the great toe significantly, and in 4 feet the pressure decreased below 40 mm Hg. When both arteries were simultaneously compressed, 69 feet showed detectable blood pressure in the great toe. Attempts to evaluate adequacy of collateral circulation by pressure blanching of the great toe prior to artery compression and then observing capillary refilling time upon release of toe compression proved unreliable.