The sulcus sign tests for inferior glenohumeral instability thanks to the laxity of the superior glenohumeral ligament and coracohumeral ligament. With the patient sitting or standing, the examiner grasps the patient’s arm and pulls 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 taken into account as a positive sulcus sign.
The test is positive if a dimple or sulcus appears beneath the acromion because the humeral head is translated inferiorly. The presence of a sulcus is taken into account as a positive test result and should indicate inferior instability or inferior glenohumeral ligament laxity. Originally described by Neer and Foster in 1980 and reported as an important finding within the diagnosis of multidirectional instability.
Test
The patient is examined in sitting or standing and the shoulder is in a neutral position. It is important that the shoulder muscles are relaxed and that stress is applied above the elbow. (This eliminates the effect of the biceps and
triceps brachii).
With the arm grasped inferior traction is applied. The examiner watches for a dimpling of the skin below the acromion. Palpation reveals the widening of the subacromial space between the acromion and the humeral head.
Positive
- Grade as: I II III
- or 2cm translation
Research
No available data
Reported as the essential diagnostic criteria for Multidirectional Instability, however, it should be noted that this could also be a sign of a rotator interval lesion and/or an injury of the superior ligament complex (in Multidirectional instability there is usually a convincing sulcus bilaterally). This type of lesion should be considered especially if the amount of inferior translation does not decrease with external rotation.
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