Allen's Test 💛 Allen's test or the Allen test is a medical sign used in physical examination of arterial blood flow to the hands. 1. The hand is elevated and the patient is asked to clench their fıst for about 30 seconds. 2. Pressure is applied over the ulnar and the radial arteries so as to occlude both of them. 3. Still elevated, the hand is then opened. It should appear blanched (pallor may be observed at the finger nails). 4. Ulnar pressure is released while radial pressure is maintained, a