There are 54 documented physical tests for diagnosis of the sacroiliac joint,4 the majority of which assess the comparative mobility of the involved versus uninvolved joint. While these tests are popular and clinically effective in most hands, mobility testing has limitations including poor inter-tester reliability.
More reliable is provocation testing. A 2005 study which compared the diagnostic validity of sacroiliac joint provocation tests with positive response to diagnostic injection found the sensitivity and specificity of two out of 4 positive sacroiliac joint tests to be 88% and 78%, respectively.5 A meta-analysis published in 2009 showed that the thigh thrust test, compression test, and three or more positive sacroiliac joint stressing tests, had discriminative power using a double block injection technique as the reference standard.6
The positive predictive value (PPV) of provocation testing, meaning the proportion of subjects with positive test results who are correctly diagnosed, gives practitioners a reliable means to diagnose sacroiliac pathology, and is particularly helpful when attempting to diagnose or treat a patient for whom initial or conservative treatment was unsuccessful in resolving their symptoms.
The videos below demonstrate the proper techniques for performing these provocative tests. Reproduction of the patient’s sacroiliac joint pain is considered a positive test.
Diagnosing SI Joint Disorders - Provocative Testing
Thigh Thrust (Posterior Shear)
Purpose: This test applies A-P shear stress on the sacroiliac joint. Patient Position: Supine, hip flexed to 90° with the knee relaxed. Action: The examiner then applies a gradual, sustained, vertically directed force through the femur.
Purpose: This test applies tensile forces to the anterior sacroiliac joint. Patient Position: Supine, lower extremities extended. Action: With arms crossed, and one hand over each ASIS the examiner applies gradual sustained posterior-lateral pressure.
Purpose: This test applies tensile forces to the anterior sacroiliac joint ligaments. Patient Position: Supine, the hip flexed, abducted and externally rotated and the foot resting on the opposite knee. Action: The examiner then applies gradual, sustained downward pressure on the flexed knee.
Purpose: This test applies torsional stress on the sacroiliac joints; nutation motion on extended side and counter nutation on flexed side, both of which can both elicit sacroiliac pain. Patient Position: Supine, one lower extremity flexed to the chest and the opposite limb allowed to hang over the edge of the table. Action: The examiner performs simultaneous gradual, sustained extension pressure to one hip and flexion pressure the opposite hip.
Reproduction of the patient’s sacroiliac joint pain is considered a positive test.