Fold patient thumb into closed fist ; Test is positive if Patient thumb tip extends from Palm of Hand. ______________________________ b.Walker-Murdoch sign >>>>>>>>>>>>>>>>>>>> Because of long fingers and thin forearm, thumb and little finger overlap when patient grasps wrist. If a person has Hypermobility + Sternberg sign + Walker-Murdoch sign the chances are close to 90% that the person has Marfan Syndrome.