There are several different factors that can cause SI joint pain and dysfunction. One of the most common causes is an injury. The injury can come from a direct fall on the buttocks, a motor vehicle accident or a sports related trauma. The force from these injuries can strain the ligaments around the joint. Tearing of these ligaments can lead to hypermobility in the joint. This excess motion and lack of stability is thought to be the main cause behind sacroiliac joint dysfunction.
Pregnancy may also be a factor in the development of SI joint pain. Women secrete the ‘relaxin’ hormone during pregnancy. This hormone allows the connective tissues in the body to relax. The relaxation is needed so the pelvis can stretch enough to allow the baby to pass during labor. This stretching may affect the SI joints causing them to become hypermobile. The more pregnancies a woman has, the more chance she has of developing SI joint pain.
Leg length discrepancies may also play a role in sacroiliac joint dysfunction. If a person has one leg that is shorter than the other, the abnormal alignment may end up causing SI joint pain or malalignment issues.
Often, an exact cause leading to SI joint pain cannot be found. The joint simply becomes painful, and the patient and their local physician do not have an answer as to why the joint has become troublesome. It takes a trained health care provider to accurately diagnose and treat sacroiliac joint pain.