Back Pain in Early Pregnancy
Up to 50% of pregnant women complain of back pain in early pregnancy. Pregnancy causes a change in hormones levels, in particular a hormone called relaxin is released. Relaxin is important as it allows the joints in the pelvis to move, enabling the baby to be accommodated in the pelvis and essentially allowing it to come out when the time is right.
To understand the importance of this it’s worth taking a look at the anatomy of the pelvis.
The pelvis is made up of two large bones, the ilium, and they attach to the sacrum at the back of the spine. Where the ilium and the sacrum meet, there is a joint. This joint is called the sacroiliac joint.
The sacroiliac joint is a pretty special joint, normally it barely moves at all. It’s a very stable joint. This is partly due to the shape of it – both the surfaces of the ileum and the sacrum are knobbly and fit to together very snugly. Further support for the joint comes from very large strong ligaments and from some of the key muscle groups that surround it.
I n order for the baby to be born the sacroiliac joint needs to move outward. This is the role of the hormone relaxin, it causes the ligaments holding the joint together to soften and allow movement.
This softening may be why there is a link between sacroiliac joint pain and back pain in early pregnancy.
It’s also worth thinking about the effect of the hormone relaxin on the other ligaments in the back. It is not selective, all ligaments become lax, even your knee joints when you are pregnant. So it’s not really surprising that back pain during early pregnancy occurs.
Lower Back Pain Toolkit Home Page
Causes of Back Pain in Pregnancy
Treatment of Lower Back Pain during Pregnancy
Pregnancy and Back Pain - Sacroiliac Joint Dysfunction
20-Nov-2009
