Why We Must Utilize More Than Pain Provocation Tests for SIJ Dysfunction

We are once again back on the topic of SIJ Dysfunction. A couple months ago, we had a pretty controversial post about non-painful sacroiliac joint dysfunction. A large part of our discussion was on the basis of how limitations in SIJ mobility could alter the normal stresses in adjacent joints. While we still believe this is an important aspect, in the past few weeks we have become aware of yet another reason for regularly assessing the sacroiliac joint.

Something that is often lost in the effects of SIJ dysfunction is impact on muscle alignment. Any time there is a deficiency in the alignment of the joint surfaces, the origin or insertion of the muscles are altered, thus changing the moment arm of the muscle as it crosses its respective joint. These changes may seem small and insignificant, but they can result in both muscle pain and weakness. The significance of a muscle alignment issue is that these patients will likely not have many positive pain provocation tests, because it is not the joint that is painful - it is the muscle (or structures near the muscle). Therefore, when assessing the sacroiliac joint, be sure to assess the symmetry and depth of SIJ structures such as the PSIS, sacral sulci, sacral ILAs, ischial tuberosities, and more. In the past few weeks, we have had multiple patients with pain or weakness that was eliminated or minimized simply by doing a sacral mobilization or other manual technique to correct the asymmetry. These patient's had negative pain provocation testing but noticeable bony landmark asymmetries. We are aware of the fact that SI mobility tests are unreliable according to several research studies, but we again argue that they should not be forgotten. This brings up the importance of testing and re-testing after a treatment. A muscle that appeared weak initially in your eval may be normal after correction. If you can show immediate changes in pain and strength from a treatment directed at the SIJ, not only will it potentially alter your plan of care, but it also builds your patients' confidence in you as a clinician! 

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