What you should know about your psoas muscle

I had a question about the psoas muscle this week, so I thought I would write a post about it for all of you.

I love talking about the psoas muscle. It is a large, deep muscle that can show up in mysterious ways.

Back pain? Might be the psoas.
Groin pain? Might be the psoas.
Pain with walking or running? Might be the psoas.

Let's demystify it.

It can be hard to describe where this muscle is without a picture. Look at the image below and notice where the psoas begins (don't worry about the minor or major). It starts on the inside of the lumbar spine, attaching to the transverse processes. It even attaches to the intervertebral discs themselves. It cannot be touched from your back, it is too deep.

Follow the muscle down, through the pelvis, and see how it attaches to the inside of the femur bone (the thigh bone). The part of the femur it connects to is called the lesser trochanter. You can try to feel this on the inside of your thigh, but it is pretty deep in there.

​If you have ever had your psoas muscle palpated, it was from the front, through your abdomen. It is not always a pleasant sensation. And if it was tender, you knew when it was touched!

The job of the psoas muscle is flexion. In standing, to lift your right leg, your psoas muscle needs to shorten. As it shortens, your hip flexes.

If you are flat on your back and you want to pull your right leg up toward your body, your psoas will shorten and bring your leg up.

If you are flat on your back and you want to sit straight up, your psoas will help pull your body up into the sitting position. This is why a full sit-up doesn't work just your abdominals.

Now let's talk about stretching your psoas muscle. After a prolonged day of sitting, with your psoas in a shortened position, try this psoas stretch with a chair.

Can you picture how the muscle is lengthened in this video?

I hope you now know a bit more about your psoas muscle. I am a big anatomy nerd, and sharing anatomy bits with you is fun. I hope you find some fun in knowing all about your body as well.