The sacro-iliac joint (SIJ) is a joint where the ilium (hip bone) meets the sacrum (tailbone). Pain arising from the sacro-iliac joint is typically located right on the joint, but may refer into the buttock, groin, on even below the knee. A study by Slipman et al (2000) found that 94% of patients with confirmed SIJ pain had buttock pain, 28% of patients had pain below the knee, and 14% had referred foot pain.
It is now generally accepted that around 13% of people with persistent low back pain, have the origin of pain confirmed as the SIJ (Maigne et al 1996). The joint itself only has a very small range of movement, less than 4 degrees of rotation and 1.6 mm of translation (Sturesson et al, 1989). And the joint was found to have the same range of movement in asymptomatic patients.
Many physiotherapist’s, chiropractor’s, osteopath’s and other health professionals talk about SIJ dysfunction, and use a battery of SIJ tests to identify ‘SIJ dysfunction’, claiming the joint is not moving correctly and this is the source of the pain. And yet the research does not support the validity or reliability of these tests. Commonly used tests for SIJ diagnosis such as palpation have shown poor reliability, as have frequently used tests like the Gillet test, standing flexion and sitting test (Laslett, 2008). Many asymptomatic people show positive tests, and the tests have a high false-positive rate (show a positive SIJ test where the problem is not actually confirmed as being from the SIJ).
SIJ provocation tests, and how to differentiate pain coming from the low back versus the SIJ
Given the lack of ability to determine the SIJ using palpation or movement tests, further research was conducted on the SIJ using pain provocation tests. Pain provocation tests are tests that produce the sufferer’s exact symptom, as opposed to be being based on abnormal movement.
It was shown that a cluster of SIJ provocation tests (3 of 6 pain provocation tests, or 2 of 4) had 94% sensitivity (those that do not have SIJ pain are correctly found to have negative tests 94% of the time), and 78% specificity (those that do have SIJ pain are correctly identified 78% of the time) when the lumbar spine is ruled out.
Given the lower back can produce false-positive SIJ tests (tests appear to suggest the SIJ as the source of pain, but then become negative once the lumbar spine is evaluated first), a repeated movement exam of the lower back using the McKenzie Method is used. This McKenzie Assessment of the lower back involves repeated movements, attempting to identify Centralization. This refers to the pain in the buttock or lower leg moving to a more central location in the spine, and is associated with discogenic pain as the source of the problem (Laslett, 2008).
Thus these cluster of positive SIJ provocation tests are highly reliable and accurately identify the source of the pain coming from the SIJ, but only once the lower back is excluded first.
And basically if you do not test positive to at least 2 of these tests your pain is not coming from the sacro-iliac joint.
So what do I do if I think I may have SIJ pain?
The evidence suggests you need a McKenzie Assessment of your lower back first to either relieve the pain and resolve the problem with direction specific lower back exercises, or to rule it out and identify the SIJ as the actual source of pain (Laslett et al, 2003).
There is some preliminary evidence that if the lumbar spine is ruled out with a McKenzie Assessment of repeated movement, that some SIJ problems will resolve with direction specific SIJ exercises (Horton and Franz, 2007), and clinically I have seen this myself quite commonly.
Other SIJ problems are primarily inflammatory in nature, and this is more likely if the pain is of a constant nature (McKenzie Institute International, Part C Manual 2015), and there has been no relief with either repeated lumbar or SIJ movements. Some of these people will respond to an injection into the SIJ (with corticosteroid) or to oral anti-inflammatory medication.
Come into Melbourne’s CBD and see our McKenzie Method physiotherapist Joel Laing (Diploma in MDT) to determine the source of your pain without the need for expensive imaging, and to find a simple, effective specific exercise to resolve your problem.
Horton, S. and Franz, A. (2007). Mechanical Diagnosis and Therapy approach to assessment and treatment of derangement of the sacro-iliac joint. Manual Therapy, 12(2), pp.126-132.
Laslett, M. (2008). Evidence-Based Diagnosis and Treatment of the Painful Sacroiliac Joint. Journal of Manual & Manipulative Therapy, 16(3), pp.142-152.
Laslett, M., Aprill, C., McDonald, B. and Young, S. (2005). Diagnosis of Sacroiliac Joint Pain: Validity of individual provocation tests and composites of tests. Manual Therapy, 10(3), pp.207-218.
Laslett, M., Young, S., Aprill, C. and McDonald, B. (2003). Diagnosing painful sacroiliac joints: A validity study of a McKenzie evaluation and sacroiliac provocation tests. Australian Journal of Physiotherapy, 49(2), pp.89-97.
Maigne, J., Aivaliklis, A. and Pfefer, F. (1996). Results of Sacroiliac Joint Double Block and Value of Sacroiliac Pain Provocation Tests in 54 Patients With Low Back Pain. Spine, 21(16), pp.1889-1892.
Slipman, C., Jackson, H., Lipetz, J., Chan, K., Lenrow, D. and Vresilovic, E. (2000). Sacroiliac joint pain referral zones. Archives of Physical Medicine and Rehabilitation, 81(3), pp.334-338.
STURESSON, B., SELVIK, G. and UDÉN, A. (1989). Movements of the Sacroiliac Joints. Spine, 14(2), pp.162-165.