WHAT IS THE SACROILIAC JOINT (SI JOINT)?
The sacroiliac joint is a firm, small joint. The sacroiliac joints are two paired “kidney bean” or L-shaped joints that lie at the junction of the spine and the pelvis. Most often when we think of joints, we think of knees, hips, and shoulders–joints that are made to undergo motion. The sacroiliac joint does not move much, but it is critical to transferring the load of your upper body to your lower body. The SI joint is one source of low back and buttock pain. The SI joint is implicated as a cause of low back pain in at least 13% and perhaps as high as 30% of cases. Women are considered more likely to suffer from sacroiliac pain than men, mostly because of structural and hormonal differences between the sexes.
The hormonal changes of menstruation, pregnancy, and lactation can affect the integrity of the ligament support around the SIJ, which is why women often find the days leading up to their period are when the pain is at its worst. During pregnancy, female hormones are released that allow the connective tissues in the body to relax. The relaxation is necessary so that during delivery, the female pelvis can stretch enough to allow birth. This stretching results in changes to the SIJs, making them overly mobile. Over a period of years, these changes can eventually lead to wear-and-tear arthritis. As would be expected, the more pregnancies a woman has, the higher her chances of SI joint problems Trauma, muscle imbalance, and hormonal changes can all lead to SIJ problems.
Exercise rehabilitation is an integral part of the recovery from SIJ pain. Stretching, massage and joint mobilisation/manipulation are useful in correcting any imbalances that may exist around the SIJ. Sacroiliac belts may be useful in the management of overly mobile sacroiliac joints for example during pregnancy.