Forwarded this in an email? Subscribe for all things bendy here:

The psoas is the brooding, mysterious, yet deeply alluring bad seed of the muscle posse. Entire books are dedicated to the psoas. It is powerful, weird, problematic, and a frequent scapegoat for lower back and hip pain.

I had constant psoas spasms from childhood well into my 30s. This is not uncommon for folks on the hypermobility spectrum and nothing really seemed to make it go away until my life-changing hip stabilization realization of 2010 that finally allowed my hip flexors to relax (read about that here).

I wanted to explore that realization in a little more detail by focusing on the psoas, what it does, why it is so hard to relate to, and what I did to befriend it.

I also have a 30-minute video available on the new Fit & Bendy online platform that shows you how to do the exercises I’m describing below. I’m making it available for free this week to accompany this post.

As the title of this piece suggests, the psoas muscle is the only muscle that links the upper and lower hemispheres of the body. Its trajectory is pretty wild.

At the top it’s fastened on to the inside of your spine (T12- L5), reaching high enough to interface with the diaphragm muscle just below the rib cage. Then it swoops down, running in between your internal organs and the basket of muscles that makes up the pelvic floor, and then waterfalls over the front of the pelvis to wiggle down into the upper inner thigh and attach to the lesser trochanter of the femur.

It has a best friend called the iliacus that also attaches to the lesser trochanter of the femur but only runs as high as the inside of the pelvis. These two work together so often that they are often referred to as the iliopsoas - the original ship name.

Because of its length and quirky placement, the psoas is involved in many important jobs. It is perhaps best known as a hip flexor, but it can also externally rotate the femur and provides essential hip stabilization in movement. Equally important, the psoas is a spinal flexor, working to hold your body upright and maintaining lumbar lordosis (that forward curve of the lower back). It can also help with side bending and provides spinal stability.

That is a lot of jobs.

When the psoas is strong, healthy, and supported it is a superhero of a muscle. But it is far too easy for this muscle to get squashed, neglected, unsupported, resentful, and even vengeful.

Imagine that you ran your big truck off the road into a ditch and you need to winch it out. Now imagine that the only thing around to anchor the winch is a skinny little tree. Picture what would happen as you started to crank the winch: the tree would bend more than the truck would lift.

This is often what happens when we try to access the psoas as a hip flexor. The psoas is the winch, your thigh is the truck, and your lumbar spine is that sapling. The lumbar spine is one of the most structurally mobile parts of the body, relying on core muscles to provide support. If it lacks support the psoas will pull the lumbar spine out of alignment rather than successfully lift the thigh. Any attempt to lift the leg turns into spinal extension (sway back) and rotation.

For the same reason, it is hard to lengthen the psoas. If you have ever done a lunge and noticed that you can go much deeper and feel better if you arch your back, that is because you have let go of one end of the psoas and it is no longer being stretched.

This means that it is extremely difficult to strengthen or stretch the psoas muscles without the solid spinal stability that comes from deep core strength.

It is also important to note that we humans have a harder time engaging with muscles that we can’t see or touch. It’s easier to strengthen muscles in the front of the body than the back. Because the psoas runs through the middle of the body it’s hard to feel it or poke at it.

Finally, sitting force shortens the psoas, along with all the other hip flexors. There is nothing a muscle hates quite like prolonged forced shortening and this can make muscles short, tight, and sleepy.

Important side note: while I’m focusing solely on the physical causes of tightness, much has been written about the psoas as a common receptical of emotional stress and tension as well. It has certainly been my experience that stress makes me more likely to have psoas spasms.

As G.I. Joe once said, knowing is half the battle (shoutout to my fellow Gen Xers). It’s very hard to help a muscle that you don’t understand, so I recommend starting by really getting to know where the psoas is and how it works. You can start with this animation:

I also recommend spending some time trying to palpate your own psoas. This isn’t always possible since you have to push through visceral fat, three layers of abdominal muscles, and sometimes a bit of intestine to get there but it’s definitely worth a try. Touching a muscle as you try to engagement gives you powerful proprioceptive feedback. The workout I link to below includes a tutorial on how to squish around in your belly to find it.

Leg lifts are definitely an exercise that can strengthen the psoas, but if you don’t have the strength to anchor your spine they will not have the desired effect. The target core muscles, which I like to call our meat corset, are the internal and external obliques and the transverse abdominus. These muscles are essential companions to a healthy psoas.

The easiest way I have found to anchor the spine is to lay on the floor on your back with a small rolled up towel under the lumbar spine. This preserves our normal spinal curve but doesn’t allow it to move around much. Then the core muscles can work to hold your pelvis and spine still as you start to move the femur.

A muscle is generally easiest to engage in its mid range so I like to start psoas engagement exercises laying on the back with lumbar spine support and the working leg slightly elevated on a block or chair. Then, once your spine and pelvis feel aligned and anchored, you can start to flex the hip, bringing the knee towards the chest.

If you are brand new to psoas work the initial flexion may mean just dragging the working leg a few inches towards you and resetting. Lifting the weight of the entire leg may still feel like too much.

Over time you can increase the difficulty and range of hip flexion, even working into positions where the psoas is stretched. However I always start with engaging the psoas rather than stretching it, even if it is horrifically tight. See my below referenced post on the importance of stabilization to combat chronic tightness.

If you want to try my 30-minute follow-along exploration of the psoas, you can access it for free on the new workout platform.

Check it out here:

If you do try it out please let me know your experience!

Next week I’m going to nerd out on shoulder structure and why you might feel an unhappy pinching in the shoulder joint when you lift your arm.

P.S. Before the Intro to Contortion series kicks off on October 17th, I'm doing a debut livestream this Saturday October 10th at 11am Pacific to break in the new platform properly. It's a one-hour gentle full-body dynamic mobility session, perfect for all levels and a great way to try the new platform. Register here!

Further reading:

Try it in action
Access the 30-Minute Guide to Taming Your Psoas free with a 14-day trial of the new Fit & Bendy platform — plus 70+ other workouts and weekly livestream classes.

Know someone who's been blaming their psoas for all their problems?
Share this newsletter with them and I will be forever grateful!

👉 {{rp_refer_url}}

Get the newsletter
Every week I write about the science of flexibility, mobility, and movement — for all levels. Subscribe free here.