Thigh Thrust Test

The Thigh Thrust Test (also called the Posterior Shear Test) is an orthopedic provocation maneuver used to screen for sacroiliac joint (SIJ) dysfunction or pain by applying a targeted shearing force across the SI joint. It is especially useful in identifying whether SIJ pathology is contributing to a client’s low back, buttock, or pelvic pain.

Thigh Thrust Test

How is the Test Performed

  • Client position: Supine (lying on the back) with the hip and knee of the tested side flexed to 90° and slight adduction.

  • The therapist stands on the side to be tested and places one hand over the sacrum to stabilize the pelvis.

  • The examiner then applies a linearly increasing anteroposterior force (downward push) along the femur, generating a shearing stress through the SIJ.

  • The maneuver can be repeated 3 to 6 times or as a continuous pressure.

  • A positive test: Reproduction of the client’s typical SIJ region pain during pressure.

Clinical Significance

  • The Thigh Thrust Test has good sensitivity (~88%) and moderate specificity (~69%) for detecting SIJ dysfunction.

  • It is best used as part of a multi-test cluster (usually including FABER, Gaenslen, Compression, and Distraction tests); the likelihood of SIJ pathology increases as more tests are positive.

  • Pain provoked by this maneuver that matches the client’s symptoms strongly suggests the SIJ as the pain source; but the absence of pain does not conclusively rule out SIJ issues.

Assessment

  • Use the Thigh Thrust Test for clients with low back, buttock, or pelvic pain where SIJ involvement is possible.

  • Always compare both sides (even if symptoms are unilateral) and document pain intensity, location, and whether it matches the client’s typical complaint.

  • Remember that the Thigh Thrust Test is only one part of a broader SIJ assessment.

Treatment

  • If positive:

    • Avoid deep tissue work, high-velocity manipulation, or forceful stretching or mobilization directly over the SIJ.

    • Focus on gentle soft tissue therapy to surrounding gluteals, lower back, and pelvic stabilizers, and pain-modifying approaches.

    • Educate clients about pelvic stability, proper lifting, posture, and activity modification to minimize SIJ shearing and aggravation.

    • Refer to other health professionals for persistent, severe, or complex SIJ pain, or when medical imaging or a multidisciplinary approach is indicated.

Safety and Referral

  • Always refer clients for further evaluation if red flag symptoms, severe or persistent SIJ pain, or associated neurological symptoms are present.

  • Collaborate with physiotherapists, physicians, and other relevant professionals for complex or non-resolving cases.