A New Validated SI Provocative Test

Reference:Werner CM, et al Distraction test of the posterior superior iliac spine (PSIS) in the diagnosis of sacroiliac joint arthropathy. BMC Surg. 2013 Oct 31;13:52.

There are a number of provocative tests for the SI joint out there and I usually limit myself to 2-3 per patient, per session in order not to irritate them. I admit I have rarely used the PSIS distraction test.

What is the PSIS distraction test?

With the patient in prone lying, the PT thumbs are placed medial to the PSIS and the hands are flared around the ilium. Then a quick, jerky and fairly strong force is applied on the PSIS in medial-to-lateral direction.

+ve test: the patient reports reproduction of their unilateral low back pain
-ve test: no symptoms reproduced

Challenge: It cannot definitively be proven if the tenderness of the PSIS is caused by an intra-articular pathology or rather a peri-articular (i.e. ligamenteous) problem.

In this 2013 study, when compared to other provocative SI tests, the PSIS distraction test was found to have the best sensitivity and specificity.


If +ve: An SI joint irritation is likely present
If -ve: Low back pain is unlikely related to an SI joint irritation

Personal comment: Just palpation of the PSIS region is often tender; perhaps it’s not the test!

Posted on: March 10, 2014

Categories: SI & Pelvis

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