Facts about the sacroiliac joints and pelvis

The sacroiliac joint (SIJ) connects the hip bones (iliac crests) to the sacrum, the triangular bone at the base of your lower back, above the tailbone.

The pelvis and SIJs (we have 2) are designed primarily to transfer load, and are therefore extremely stable and can transfer huge amounts of load safely.

The SIJs allow very little movement, about 2 degrees of rotation maximum.

The strength and stability of the pelvis and SIJs mean that it is practically impossible to put these joints ‘out of place’.

If you feel, or can visibly see that one side of your hip bones (iliac crests) sits higher than the other or looks different, this is likely due to altered muscular activity rather than a joint being displaced. This is common and is not dangerous.

During pregnancy, hormones are released which soften the ligaments around the pelvis and SIJs, allowing for the natural birthing process.These hormones remain in the body for about 3 months.

Pelvic girl pain is extremely common during and after pregnancy, affecting about 1 in 4 women.

Pelvic girdle pain may be associated with either excessive or insufficient recruitment of the musculature around the back, pelvis, abdomen and hips.

There is strong evidence that intra-articular displacements within the SIJ’s do not occur and pelvic manipulation does not alter the position of the pelvis.

Bottom line: Your pelvis and SIJs are extremely strong and robust structures that can transfer and tolerate huge loads.