(Adapted from Cecile Rost, 2007)
Pain arising from the joint that attaches the sacrum and the ilium together is called sacroiliac joint pain. Sacro-iliac (SI) joint pain can also be caused by problems in any of the joints of the pelvic girdle including the pubic joint (pubic symphysis) and the sacral-coccygeal joint (joint between the sacrum and tailbone). The SI joints are very important since they transfer the weight from our legs to our trunk during movement.
The bones of the pelvic girdle form a ring that is held together with ligaments and muscles. These ligaments relax and stretch in response to hormonal changes during pregnancy, in order to expand the birth canal for delivery. This hormonal relaxation results in the lengthening, and often weakening, of the ligaments of the pelvic joints and the surrounding muscles, which all provide stability to the pelvic ring. Therefore, pregnancy is one of the leading causes for sacro-iliac joint problems. Other causes of SI joint dysfunction can include trauma, and various sporting injuries.
Pelvic Floor muscle problems can also cause pain in the sacro-iliac joints. Pelvic floor muscle tightness can slacken the posterior (back) ligaments of the SI joint, and weak pelvic floor muscles can create decreased stability in the SI joints. In other words, if your pelvic floor is too tight or weak, it will de-stabilize the sacroiliac joints.
Having an “unstable” pelvis is a normal condition in pregnancy, and doesn’t necessarily lead to pain. In fact, it is important to have “looseness” in these joints to facilitate delivery. However, research shows us that women who experience pelvic pain have a different amount of laxity between their right and left sacroiliac joints as compared to pregnant women who don’t have SI joint pain. Therefore, it may be the imbalance between the “looseness” of the ligaments from left to right that is important. A large enough difference in laxity may cause a minor displacement of the ilium, or the portion of the pelvic girdle that has the most freedom to move. It is thought that the pain arises from the asymmetry that occurs as a result of a slightly shifted ilium and/or sacrum into a badly recognized position by the brain. As a result of the “new” position in the sacroiliac joint, one will unconsciously try to restore the situation, and muscles will tense and pull within or around the pelvis. This ongoing tension in muscles that are not supposed to be chronically tensed may cause the brain to produce pain in response to this ongoing activity. If you had pre-existing Pelvic Floor Muscle Tightness, and/or tightness in the muscles of the inside of the leg (adductor muscles), this will also worsen the asymmetry and provoke pain in the pelvic girdle. Therefore, we should call this condition an asymmetrical pelvis not an “unstable” pelvis. The pelvis is never going to crumble, or fall apart, even though the pain can be so bad that this is exactly what it feels like is happening.
Women who are at risk for pelvic pain during pregnancy are:
- Women who did a lot of swimming because of the tension placed on the adductor and pelvic floor muscles during this activity (likely chronically tense before pregnancy began)
- Women who had low back pain prior to pregnancy
- Women who have demanding jobs, particularly with prolonged standing
- Think about SI joint pain like a train derailment. The train is the ilium, which has derailed from the sacrum.
- The railway system (the body) is paralyzed at once, and the railway workers (nerves and muscles) panic.
- Transportation (body movement) must continue, so buses are called in (muscles that would normally carry out other functions), sent by the railroad’s central administration (the brain). Once the train is put back on track (via Symmetry Exercises) and the symmetry (balance) is restored, the panic subsides. Traffic returns to normal, and slowly the malfunctions (pain complaints) disappear.
Think about SI joint pain like a train derailment. The train is the ilium, which has derailed from the sacrum. The railway system (the body) is paralyzed at once, and the railway workers (nerves and muscles) panic. Transportation (body movement) must continue, so buses are called in (muscles that would normally carry out other functions), sent by the railroad’s central administration (the brain). Once the train is put back on track (via Symmetry Exercises) and the symmetry (balance) is restored, the panic subsides. Traffic returns to normal, and slowly the malfunctions (pain complaints) disappear.
Check out this YouTube video on Strengthening The Pelvis When The Pain Is Under Control. These exercises should be done once you have worked on the Stabilization exercise for several days to a week, and the pain is well controlled.
For more information and self-treatment options, a good resource is Relieving Pelvic Pain During and After Pregnancy by Cecile Rost (2007).