Jerk Test | Posteroinferior Labral Tear | Shoulder Assessment

The Jerk Test has moderate validity to confirm and good validity to rule out posteroinferior labral lesions. Kim et al. (2004) have found a sensitivity of 90% and a sensitivity of 85%, while Morey et al. (2018) found a sensitivity of 62.5% and a specificity of 96.4%.  A painful Jerk Test is a predictor of failure of conservative treatment.

To execute the test, the patient is in sitting position, and the examiner positions himself behind. The examiner stabilizes the scapula with one hand and holds the patient’s affected arm at 90° abduction and internal rotation. Then the examiner applies a longitudinal force through the humerus at the elbow and moves the arm into horizontal adduction.

This test is positive if the patient experiences a sudden onset of posterior shoulder pain and a click in the shoulder. A painful response is also a predictor of failure for conservative treatment.

Other common orthopedic tests to assess posterior instability of the glenohumeral joint are:

Miniaci Test

Kim’s Test

Porcellini Test

Kim SH, Park JC, Park JS, Oh I. Painful jerk test: a predictor of success in nonoperative treatment of posteroinferior instability of the shoulder. The American journal of sports medicine. 2004 Dec;32(8):1849-55.

Morey VM, Singh H, Paladini P, Merolla G, Phadke V, Porcellini G. The Porcellini test: a novel test for accurate diagnosis of posterior labral tears of the shoulder: comparative analysis with the established tests. Musculoskeletal surgery. 2016 Dec;100(3):199-205.