a tourniquet test used to determine the presence of vitamin C deficiency or thrombocytopenia; a circle 2.5 cm in diameter, the upper edge of which is 4 cm below the crease of the elbow, is drawn on the inner aspect of the forearm, pressure midway between the systolic and diastolic blood pressure is applied above the elbow for 15 minutes, and a count of petechiae within the circle is made: 10, normal; 10-20, marginal; more than 20, abnormal. SYN: capillary resistance test, Rumpel-Leede sign, Rumpel-Leede test, vitamin C test.