The Sacroiliac Joint



The sacroiliac joint (SIJ) is an often underlooked potential source of lower back pain.


It's particularly common to be a source of lower back pain during pregnancy and following motor vehicle accidents, though it can be a source of lower back pain in a number of other situations as well.


Pain from the SIJ is generally felt lower than other lower back pain, and can refer to the buttocks and/or thigh.


So what is the SIJ?


The SIJ is the connection between the spine and the pelvis. As the name suggests, it is the joint between the sacrum and the ilium of the pelvis. The sacrum is just below the lower back and is made up of five vertebrae that are fused together. A very small amount of movement is available at the SIJ, while it's main role is to stabilise between the lower limbs and the spine.


Pain from the SIJ is generally caused by a lack of stability in the joint. This may be due to injury to the joint's ligaments, and/or from a lack of tone in postural muscles which help stabilise the joint.


How is it treated?



SIJ pain is treated with a combination of manual therapies (including joint mobilisations and soft tissue massage) and exercise. The exercises are aimed at improving muscle tone in muscles which contribute to the stability of the joint. These generally include abdominal muscles and pelvic floor muscles, though a total of 35 muscles act on the SIJ, including gluteals, hamstrings, adductors and lower back muscles.


An SIJ belt, which provides compression across the pelvis to help stabilise the SIJ, can be worn to help alleviate pain until symptoms subside.


If you're being affected by stubborn lower back pain, see our physiotherapist in Aubin Grove to help get it treated today!