The sacroiliac joints are comprised of ligamentous tissue. These tissues are very dense and built to withstand the forces that move from the upper body to the lower. The problem comes, however, when muscular imbalances are present which alter normal movement. At this point, forces are no longer dissipated throughout many structures, but instead may be focused upon the sacroiliac joints. In this scenario, the joints may become strained, or even subluxed, which can create a tremendous amount of discomfort.
When the sacroiliac joints are "out" of alignment, the muscles around the area will frequently be locked up. This makes it very difficult to perform corrective exercises or stretching due to the pain. The more useful approach in this situation is to mobilize the joints with either special SI joint mobilizations, or visiting a good manual therapist or even chiropractor.
Once the joints at set, pain relief can be VERY fast. It is not uncommon for a patient to go from a 7 or an 8 on a pain scale of 10 to go down to a 2 or a 3 after an appropriate adjustment or mobilization.
After the normalization of pelvic alignment, exercises and stretches must be assigned to specifically address the muscle imbalances that caused the sacroiliac joint dysfunction in the first place.
