Video 2.6. The External Rotation Lag Sign

The examiner demonstrates the external rotation lag sign on a patient with a rotator cuff tear. A test is considered positive if the patient is unable to maintain the position of maximal external rotation and if the arm falls into internal rotation. A positive test is specific for full-thickness tears of the infraspinatus. Here, the patient is unable to maintain the position of maximal external rotation and the arm drifts into internal rotation. The test is positive.