Purpose: To Test for the presence of shoulder instability.
Test position: Sitting or standing.
Performing the Test: The examiner grasps the wrist of the patient's elbow and pulls the arm distally. Observation is made of the amount of "sulcus" (space between the acromion process and humeral head) that is present with the distal arm pull. A positive test is considered for multidirectional instability if 1-2 cm of "sulcus" is noted.
Diagnostic Accuracy: Unknown.
Importance of Test: Multidirectional instability (MDI) at the shoulder was first defined by Neer and Foster in 1980. Many cases of MDI are atraumatic and related to repetitive overuse, such as baseball throwing or swimming. In addition to being unstable in multiple directions, patients with MDI have excessive shoulder capsule laxity. Factors that are correlated with MDI are decreased muscular control, ligamentous laxity, labral stabilization, and biomechanical abnormalities. Typical treatment for MDI includes 1-year of conservative exercise based treatment before being considered for surgery. Because the head of the humerus is less stable within the glenoid fossa, patients with a MDI frequently subluxate or dislocate. The inferior portion of the glenohumeral capsule is often most lax, and as a result the head of the humerus can easily shift inferiorly. By applying a distal pull on the humerus, a glenohumeral joint that displays capsular, muscular, or ligamentous laxity will translate inferiorly greater than an asymptomatic joint. This excessive gapping between the acromion and humeral head is considered a positive sulcus sign.
Note: these tests should only be performed by properly trained health care practitioners.