Perfect Posture Part 4

Pelvis

This is Part 4 of a series. Please read the other three parts to have a better understanding.

This article is going to be focusing on posture as it pertains to the pelvis. This is mostly referring to the sacrum and its interaction with the lower spine and hips. In the last article we discussed the hips. That article was mostly referring to the innominate bones and head of the femur.

The pelvis is a complex joint. It is made up of the interaction between the sacrum, innominate bones, and lumbar spine, as well as all the accompanying muscles and connective tissue. Some of the joints are highly mobile as with the interaction between the femur and acetabulum discussed in the last article. Others are not highly mobile, such as the sacroiliac joint we will discuss in this article.

First let’s discuss the basic anatomy. As you can see in the image below, there’s a lot going on. The things we will focus on are the lumbar spine, wing of the ilium, sacrum, and coccyx. The rest was discussed in the previous article or are not relevant to this topic.

The sacrum is the linchpin of the pelvis. It is what connects the lumbar spine to the hips and ultimately the entire lower extremities. It is what I would call an immobile-mobile joint. It isn’t fused but it’s motion is limited.

The sacrum is almost like an extension of the lumbar spine and comes from the same embryologic origin. As we age, the individual sacral bones fuse. This image below shows a child’s sacrum which is not completely fused.