Pregnancy Related Sacroliliac Joint Pain (SIJ)

The sacroiliac joints are situated where the 2 small dimples are on the lower back. They are the joint where the pelvis and the sacrum meet. They are strong and stable weight bearing joints that allow very little movement due to the interlocking articular surfaces and the complex mesh of soft tissue structures, including the core stabilisers that create a compressive force around the SIJ.

SIJ pain occurs when the stability of the joint is compromised, and this can often happen in pregnancy. Pain can occur at any point during pregnancy and can become more intense as the pregnancy progresses.

During pregnancy a hormone, Relaxin, is released into the body causing the ligaments in the body to relax, allowing the pelvis to enlarge in preparation for childbirth. The core muscles surrounding the pelvis also get stretched and become weak with the growing uterus. Increased weight and altered walking patterns all add to the mechanical strain on the SIJs, leading to inflammation and pain.

Sacroiliac joint pain can occur on one or both sides and often feels like a deep pain in the lower back, often radiating into the buttock or front of the hip.

The pain is typically worse when standing, walking, climbing stairs, resting on one leg, getting in and out of a chair, rolling over and twisting in bed. The pain is often relieved with supported lying down.

The pain often resolves by 3 months post birth, but as Relaxin is produced by the body for up to 3 months post stopping breast feeding, SIJ pain can continue for longer without the correct stability exercises and treatment.

Pregnancy related SIJ pain can in most cases be easily relieved with physiotherapy treatment and core strengthening exercises. Pelvic girdle belts and/or other supports during pregnancy can also be used to help address the decreased stability of the joint.