Crossed fingers and other tests of ulnar nerve motor function

All tests for ulnar nerve motor function require demonstration and explanation if they are to be carried out reliably. The tests used most commonly may be difficult to elicit, particularly in children or in the presence of an acute injury. The authors have found that the ability to cross the middle over the index finger is a reliable test of ulnar nerve function. This maneuver of "crossing the fingers" is in common usage from childhood on as a good luck sign and is elicited easily in the presence of an intact ulnar nerve. An annotated table is included of other tests that may be useful in evaluating ulnar nerve integrity.