A positive posterior apprehension test indicates injury to which structure?

• A. Posterior labrum tear
• B. Anterior labrum tear
• C. SLAP lesion
• D. Glenoid fracture

Answer: (A)

The test is about posterior shoulder instability caused by injury to the posterior part of the glenoid labrum. When the humeral head is stressed in the posterior direction, a positive response—pain or apprehension—suggests a disruption of the posterior labrum that normally helps keep the humeral head centered. This is why a posterior labrum tear (often described as a reverse Bankart lesion after a posterior dislocation) is the best fit for a positive posterior apprehension sign.

An anterior labrum tear would produce instability with anterior stress, not posterior; a SLAP lesion involves the superior labrum and typically presents with pain or mechanical symptoms related to the biceps tendon rather than a posterior apprehension sign; a glenoid fracture is a bony injury with focal tenderness and radiographic findings, not specifically indicated by this posterior stress test.