Video 2.14. The Internal Rotation Lag Sign

The examiner performs the internal rotation lag sign on a patient with a subscapularis tear. The patient’s hand is placed behind his back at the level of the lumbar spine. The patient’s shoulder is passively placed in maximal internal rotation by the examiner with the patient’s hand several centimeters posterior to the lumbar spine, and the patient is asked to maintain this position away from the body. A positive test is indicated by failure to actively maintain this position and indicates a deficit of the subscapularis. Here, the patient has a positive right-sided internal rotation lag sign, but a negative left-sided internal rotation lag sign.