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What is your psoas and why, as runners, should you care?

The psoas is one of my favourite muscles in the body (if it is possible to have a favourite muscle) but it is a muscle that seems to be forgotten a lot. I am sure you have heard the term “hip flexors” and you’ve probably been told that yours are tight, but what are our hip flexors and what do they do? We have a few hip flexors in the body, but this post is going to focus on the psoas.

First though, a quick “layman’s terms” anatomy lesson. Our leg bone (the femur) is held in the hip socket by a few muscles, some at the back of our body, some on the side and some on the front. Let’s leave those rotators for another day and today focus on the muscles that pull our leg up, also known as flexion of the femur at the hip joint. (Now if you are lost already just keep reading because it will all make sense soon, I promise. Even with a Kinetics degree I still find this all confusing) I like to imagine my hip flexors like a set of venetian blinds that are broken and every time I try and pull them up only one side lifts, because the other strings have stopped working. That is sort of what happens in our hip joint. Due to muscle imbalances, usually the over dominance of other hip flexors (Tensor Fasciae Latae and Rectus Femoris) our femur flexes like those blinds when our hip flexors are not working together and pulling evenly.

The psoas is a unique muscle because it is the only muscle in our body that attaches our lower body to our torso. It also connects the back of our body to its front and the inside of our body to the outside of our body. If you look down at your belly button that is pretty much where it originates. You have one psoas on each side of your spine which travel down and insert at your lesser trochanter (your upper inner thigh). Along the way it does join with a muscle in your hip called the iliacus and the two of them together make up the iliopsoas.

The psoas pulls the torso up when the legs are fixed, and it pulls the legs up when the torso is fixed. It contracts when you are pulling your femur up past 90 degrees and it lengthens when you bring it down towards 180 degrees and beyond. Therefore, as a runner, it contracts every time you stride forward and lengthens every time you swing it back. Now, this is more conducive to sprinters because as longer distant, recreational runners, we are not following through with a high knee stride but that doesn’t mean it should still not matter to us.

Why? Because in the world of computers and commuting we spend so much of our day sitting. And when we sit our psoas becomes short, tight and weak. A short psoas is not good. Not only can it contribute to knee pain, hip pain and back pain, it can shorten your running stride, your recovery and place a ton of strain on your spine. Now that I have you convinced that this is an important muscle (you may not understand why) here is what you can do to keep it long, strong and functioning as it should.

First you will want to start with a bit of release work. Grab a medium sized ball (a tennis ball is a good option) and place it just to the side and slightly below your belly button. Position yourself on your belly, on top of the ball, resting on your elbows with some extension in your spine. You will want to bend the knee on the side where the ball is then spend some time kneading your psoas on the ball. This may feel a tad achy but if it causes pain then stop. Spend some time rolling up and down along the path of the spine on each side.

The second step is to give it a good stretch. To do this elevate your hips on a yoga block or foam roller so that you feel a small curl in your lower back (it should be rounding towards the floor). Keeping both sides your waist long pull one leg into your chest and hold it there tight while actively reaching your other leg out long allowing the hip to open.

Now that you have released and stretched it, it is time to give your psoas back some function.

Joseph (of Joseph Pilates) knew what he was doing when he created his moves and here are a few of my favourite psoas strengthening exercises. Add these to your workout or even your pre running warm up to ensure you are getting the most out of your runs and keeping yourself injury free.


This exercise targets your abs and your deep hip flexors. If you have tight hamstrings, and/or long legs, keep your knees bent for the duration of the movement. Lay on your back, legs lifted (bent or straight), and your arms extended to the ceiling. Squeeze your inner thighs together, keep your back firmly connected to the ground beneath you and then curl your upper body towards your thighs as you extend your arms out and hover them over the floor. Keeping the thighs squeezed, abs engaged, upper body curled and still, pulse your hands as you breathe in and out for counts of 5. Once you have completed 100 counts you are welcome to collapse in exhaustion before moving to the next.

Leg Circles

Ok, so this one is going to seem super easy but once you get it you will “get it”. The key here is to keep your hips completely still while you make small circles of your legs, strengthening your psoas (and other muscles). Again, with tight hamstrings you are going to keep your knee bent. Start on your back, and lift one leg to 90 degrees. Focusing on your ball and socket joint slowly stir your femur in the socket, making tiny circles. Find the muscles to do the work, not momentum. Do about 10 one way then 10 the other, keeping your pelvis still, then switch sides. Really focus on trying to pull the leg towards you with each rotation while keeping your sitbones connected to the ground.

Single Leg Stretch

Now let’s get those abs really toasty. After this sequence (don’t stop until you have finished the crisscross version) your abs will be on fire. Here, your abs are working to support your torso while you move your legs (important for runners, no?) as well as strengthening your hip flexors in the movement of the legs.

Start flat on your back, knees bent and feet on the floor (if your neck bothers you just keep your head down). Begin by bringing one knee in towards your chest and squeeze it between your hands, elbows wide. Curl your head/torso towards your bent knee and then take the other leg and straighten it out, elevated off the floor. Pull the bent knee in towards you as you exhale, inhale while you switch legs, then exhale to pull in the other leg. Make sure as you switch from leg to leg your abs stay strong, connected, and your body remains lifted and still as you should feel it rock from side to side. Do 8 on each side.

Double Leg Stretch

Next, hug both knees towards you as your curl your torso towards your knees (as if you are trying to touch your nose to your thighs). Keep the abdominal curl as you reach your hands up over your head and extend your legs out straight. Pull the legs and arms back together, connecting to your abs on an exhale, then extend long again on an inhale. You should be burning after 5.

Single Straight Leg Stretch

Keeping the upper body curled, straighten your legs, one to the ceiling and one in line with the ground. Give the leg a pull towards you on an exhale then switch the legs, like a pair of scissors, on your inhale. Keep the body still, the abs strong and the legs straight for 8 repetitions on each side.

Double Leg Stretch

Bring both legs together and straight so your toes point up to the ceiling. Imagine a little tack underneath your tailbone and keep it lifted just slightly off the tack. Squeeze your inner thighs, keep the torso curled, elbows wide and head resting in your hands. With the toes pointed inhale to lower the legs, only as low as you can keep your tailbone off the imaginary tack (I can only go about two inches). Flex your feet and exhale as you use your deep belly to pull the legs back just past 90. Go slow and allow your body time to feel this movement. 4 or 5 should be enough.


Keep your legs lifted and your hands behind your head, split your legs like a pair of scissors as you twist your upper body towards the leg that is pulling in. Slowly switch legs as you rotate to the other side. Keep an energy in your inner thighs and find your strong ab muscles to rotate your ribs from side to side. See if you can feel a connection from your armpit to the opposite inner thigh (on the side that is lifting). Do 5 or 6 on each side then extend your arms over your head and reach your legs long and take a few quick breaths.

Double Straight Leg Stretch

Last one before your abs explode. Keep your upper body curled, and zip up your legs from your ankles to your inner thighs. Keeping your pelvic floor engaged, abdominals in and your spine connected to the mat beneath you lower both legs, together, only as far as you can keep your pelvis stable (don't allow your back to arch off the floor). Once you have hit your range, pull your legs back to where you started, pulling from your deepest abdominal muscles.

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