Chapter 4

Diagnosing SI Joint Disorders: Provocative Testing

Based on very rigorously reviewed research there are five provocation tests that are used to commonly diagnose sacroiliac joint disorders.  These five tests, when used in combination, can be very accurate, both sensitive and specific, when giving information about the potential effectiveness of an injection into the SI joint.* 

Provocative tests:

• FABER - (Flexion, ABduction, External Rotation)

• Compression

• Thigh Thrust

• Distraction

• Gaenslen 

*Szadek, Karolina M, et al. “Diagnostic Validity of Criteria for Sacroiliac Joint Pain: a Systematic Review.” The Journal of Pain: Official Journal of the American Pain Society 10, no. 4 (April 2009): 354–368.


The iFuse Implant System is intended for sacroiliac joint fusion for conditions including sacroiliac joint disruptions and degenerative sacroiliitis.

Biagio Mazza is a paid consultant of SI-BONE Inc.

"We have 18 physical therapists on staff and we specialize in patients with chronic low back pain issues and that includes diagnosis of SI joint dysfunction.

The diagnosis of SI joint problems is very prevalent in our practice.  

We see a lot of people who have been either shuffled through the system with multiple other providers or have been given other diagnoses which may be seen on imaging but their true pain generator or a component of their pain generator may be from the SI joint.

In a classic study, over 22% of patients with low back pain were found to have the SI joint and SI joint dysfunction as either the primary source of pain or a component of their low back pain.

This actually correlates well with what we see with patients every day.  We see a lot of patients come in with low back pain, very few are given the true patho-anatomical diagnosis in showing exactly what’s causing their pain.  We see roughly between one in five or two in five that may have the SI joint as a pain generator.

Based on very rigorously reviewed research there are five provocation tests that are used to commonly diagnose SI joint dysfunction.  These five tests, when used in combination, can be very accurate, both sensitive and specific, when giving information about the potential effectiveness of an injection into the joint.

It’s particularly difficult to differentiate the patient whose having facet-based pain vs. SI joint pain.  

Fortunately the provocation tests will be positive in the patient with SI joint pain and typically negative in someone with facet pain.  

Also you’ll see more pain with three-dimensional motions, meaning combinations of extension, rotation and side bending or flexion, rotation and side bending with the patient with facet-based pain which you don’t typically see with someone with SI joint pain.

There are really three things that we look for when you’re trying to diagnose SI joint dysfunction away from other pathologies.  

The first is the subjective complaints of the patient, the history, seeing the location of the symptoms and then what activities provoke the symptoms.  

The second is ruling out lumbar pathology as being the culprit , so ruling out discogenic pain and facet-based problems, and then the third is positive provocation testing.  If you have those three factors in place the next step would be a diagnostic injection.

The SI joint moves very little.  It moves about three to five degrees with the normal patient.  That motion is very difficult to assess and treat with using palpation techniques.  Those assessment methods have not been found to be statistically valid.

The SI joint should be considered a potential pain generator and option for treatment in every case with low back pain.  

The diagnosis of SI joint dysfunction or at least the provocation tests should be included in every patient when they come in the door.  

When performing SI joint provocation tests it’s important to let the patient know what to expect.  You should let them know that you’re trying to provoke their symptoms and try to get an idea of where they feel them.  

When they report pain the follow up question to that would be is that your same pain that you’ve been experiencing.

One test that can be performed is the distraction test.  A pillow is placed underneath the knees of the patient, the patient’s forearm is placed underneath the low back.  

Your hands are placed on the inside of the bones of the front of the pelvis.  Arms are placed straight and the therapist or clinician leans slowly into the patient.  

How does that feel?  Where does that hurt? Is that your same pain? That would be considered a positive test.  

The thigh thrust test is performed with the patient lying on their back.  This test is considered to be one of the most sensitive and specific tests along with the compression test.  

The knee of the patient is flexed to 90 degrees.  The front of the leg is relaxed.  The knee is held and the opposite side of the pelvis is stabilized with the other hand.  Slow and steady force is placed through the femur and the patient is asked how does that feel? 

Where does that hurt? Is that your same pain? That would be considered a positive test.

The Faber test is performed as the patient lies supine.  

The knee is flexed and the leg is crossed over the opposite thigh.  The clinician’s hand stabilizes the opposite side of the pelvis.  The other hand holds at the knee and brings the leg into external rotation. How does that feel?  

Where does that hurt? Is that your same pain? That would be considered a positive test.

The Gaenslen test is a rotational torsion test of the pelvis.  The patient is asked to scoot towards the edge of the table.  

The same-side leg is dropped off the table.  The opposite leg is flexed and the patient is asked to support the knee.  One hand is placed in the front of the knee on both sides.  The patient is asked to pull the knee towards the chest as the clinician helps both legs rotate.  How does that feel? Where does that hurt? 

Is that your same pain? That would be considered a positive test.

The same test is performed on the opposite side.  The patient scoots towards the other edge of the table, the leg is dropped off.  This knee is flexed and the hands are repositioned.  Normally the clinician would be on the same side of the table.  For purposes of demonstration I’m standing opposite.  The same pressure is given and the patient is asked how does that feel?  (Patient answers)  Where does that hurt?  (Patient answers)  Is that your same pain?  (Patient answers)  That would be considered a positive test.   

The compression test is the second test along with the thigh thrust that is the most sensitive and specific combination of tests.  The patient is placed in side lying with a pillow between the knees.  The clinician places their hand 

on the outside of the pelvis and crosses their hand.  Elbows are kept straight and a pressure is forced directly into the table.  How does that feel?  

Where does that hurt? Is that your same pain? That would be considered a positive test."