SI Dysfunction: A Few Easy Diagnostic Tips

For those clinicians that go round and round with how to assess the SI joint, I thought I'd point out a few relationships I came across during my doctoral case study literature review.  My intent here is not to write a literature review, but just plant a few seeds for you to use next time you assess a patient with suspected SI pain.

1. Don't overlook manual muscle test data!  It can tell you a lot more than if a muscle is weak.  Specifically, hip abduction and the L5 myotomal test. You will very often find the side of the up-slip and rotation will have ipsilateral abductor weakness and ipsilateral L5 myotomal weakness.    Take special notice if the weakness is not bilateral.  Take extra notice if you have unilateral weakness in these areas in a fit individual.  After correcting the SI dysfunction, if your treatment is successful, these two tests will often improve immediately upon retesting the same day.
2. Long Sit Test: don't use the traditional ideas discussed in Magee to determine the effectiveness of this test (the studies show it is a poor test based on their definitions).   But when used as a broader "red flag" test, I feel it is an excellent tool.  If the malleoli change in ANY WAY during the supine to sit, don't over think it, just consider the test positive and start seriously suspecting an SI problem.  If the leg length is the same difference in supine and long sit, you have a true difference and start digging around for a heel lift (but I've found this is the minority of people).
3. Last test to consider.  The "Shotgun Test" for adduction strength in a hook-lye position.  If this test is painful or weak (or both) you probably have an SI problem.  Also will need to clear L5-S1 if this is weak.  

These tests are ones that are performed as part of most evaluations, and the Shotgun Test is used as a part of most SI treatments.  But start putting them into your mental assessment calculator, using them as possible SI tells, and you might find your success rate when treating these difficult patients goes up a notch or two.  All questions regarding this topic are welcomed.