The Jerk Test is most consistent with which elbow/shoulder pathology?

• A. Posterior inferior instability with or without posteroinferior labral tear
• B. Anterior instability
• C. Superior labrum anterior and posterior (SLAP) lesion
• D. Medial collateral ligament laxity

Answer: (A)

The Jerk Test assesses posterior-inferior instability of the shoulder, often with a posteroinferior labral tear. When the arm is brought toward the midline with a posterior-directed load through the humerus, a sudden jerk or clunk as the humeral head slides back and then reduces on the glenoid indicates posterior-inferior translation and potential labral injury. This combination—posterior-inferior instability with or without a posteroinferior labral tear—fits the test’s provocative pattern best. Tests for anterior instability, SLAP lesions, or medial elbow laxity produce different signs, so the jerk test is most consistent with the posterior-inferior pathology.