VALGUS INSTABILITY STRESS TEST FOR TEARS OF THE MEDIAL ULNAR COLLATERAL LIGAMENT The elbow joint is very similar to the knee joint. While both joints are hinge joints (when we look at the humeroulnar joint - the radiohumeral joint is a ball-and-socket joint that is restricted by the humeroulnar's shape), they are both stabilized by collateral ligaments. In order to test the medial ulnar collateral ligament, you are performing the varus instability stress test, similar to the one of the knee. No