Understanding the Posterior Shear Test (or Posterior Thigh Thrust) Assessment
To assess for dysfunction of the **Sacroiliac (SI) Joint**, specifically a posterior shearing force.
Watch How It's Done
How do I start?
Patient is supine. Hip is flexed to 90°, and the knee is flexed to 90°.
What happens?
The examiner applies a strong, axial **posterior thrusting force** through the femur (down the shaft of the femur) which stresses the SI joint.
In Plain English
What Does a Positive Result Mean?
Reproduction of the patient's **posterior buttock/SI joint pain**.
Helpful Tip:
This test is one of five cluster tests commonly used to diagnose symptomatic SI joint dysfunction.
Safety First
This guide is to help you understand what happens in a clinic. Do not try to diagnose yourself. If you have severe pain, swelling, or cannot put weight on your leg, please visit an urgent care center or your doctor immediately.
Other Hip/SI Joint Tests
Gaenslen Test
To assess for dysfunction or pathology of the **Sacroiliac (SI) Joint** or hip pathology (less specific).
Patrick's Test (FABER: Flexion, Abduction, External Rotation)
To assess for pathology in the **hip joint** (e.g., OA or labral tear) or the **Sacroiliac (SI) joint**.
Trendelenburg Sign
To assess the functional strength of the **Hip Abductors**, primarily the **Gluteus Medius** muscle.