The Mighty Psoas.

Your psoas muscle plays an incredibly important role. It is a hidden muscle tucked behind your abdomen and so it is a bit more difficult to envisage than other muscles that you can see and palpate. There are a number of reasons why it is so important.

The muscle gets its name from the Greek word, “loin”. The muscle pulls your lower spine forward giving you the curve that you can feel in your lower back.

psoas anatomy

The psoas muscle in the above picture is the muscle that originates from the spine.

  1. It is used to hold you upright.
  2. It helps you move. Your first movement as you start your run or walk is to swing your leg forward. It’s your psoas that gets you moving.
  3. It is linked to the spine. A shortened psoas will place unwanted pressure on the spine.
  4. The more you sit, the shorter the muscle becomes.

There are only 4 muscles that connect the spine to either the arms or the legs. Your latissimus dorsi, better known as your ‘lats’ connect the spine to the arms.

With regard to your legs, the glute maximus, piriformis and psoas link the spine to the legs. These muscles therefore are linked to both spinal stability and movement.

Let’s look at some of the wonderful things that the muscle helps us with.

  1. Walking and Running is initiated by the muscle.
    As you step off, your psoas pulls. Your femur gets pulled forward, and with that a whole series of events take place that enable to move. The human body is a wonderful thing.
  2. The muscle fires during stressful situations.
    You have two reactions to stress – fight or flight.
    The psoas muscle is involved in both. In other words, you will either sprint off, which means that the psoas will initiate that movement, or you will fight. Fighting means that you will pull down into a more protective position. Once again the psoas fires up. If things really go wrong and you get forced to curl up into fetal position, it’s the psoas that will curl your legs up to protect your abdomen.
    On another note, I am sure you have heard the term, “I just wanted to curl up into a ball and cry/die.” Emotions influence posture. People that have gone through stressful situations will often shorten the psoas.
  1. The muscle shortens when you sit too much. I wrote a blog entitled Sitting is the new smoking. It really is harmful.
  2. Cyclists do their thing while seated. They run the risk of over pulling with the hip flexors and thus over developing the psoas, and at the same time shortening it.
  3. A tight psoas can switch your glute muscles off.
    I have met so many athletes who have been told that their injury problems originate from weak glute muscles. They then get put on a program where they train the butt to become strong. Despite getting to the level where they can crack an acorn open between their cheeks, they remain injured. Bottom line, if your psoas is tight, your body will prevent the glutes from firing while running. The process is called reciprocal inhibition. Your body prevents two opposing muscles from contracting at the same time.  When one muscle contracts, a message is sent to the brain to tell the opposing muscle or antagonist to relax. A tight psoas will send a message to the brain that will decrease how much your leg is pulled back during the push off phase of your run. Forget about your glute firing properly if you have a tight psoas.
    I get to see this every day during our Runner’s leg assessments. As soon as the heel of the front leg touches the ground the back leg comes swinging forward and is not allowed to follow through.

What to do, what to do..?

  1. Try and sit less at work. You need to schedule regular breaks in order to stand up and walk around and maybe even get a stretch in.
  2. Stretch the muscle.
    Here are some ways. I particularly like the warrior pose. It is demonstrated on the second picture.psoas 1psoas 2
  3. Come in for a bit of Myofascial Release.
    Here are some details – Massage at SBR Sport.
  4. Get some more ideas from a pilates/yoga/personal trainer.

Hope this helps.

Mike Roscoe
Mike Roscoe.


About sbrsport

SBR Sport specialises in Swimming, Biking and Running. On the medical side we are able to do intensive bike setups, leg assessments and soft tissue release. - and/or facebook -
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4 Responses to The Mighty Psoas.

  1. Pingback: Happy & Healthy Hips. | SBR Sport

  2. Pingback: The damage you do when you sit too much. | SBR Sport

  3. Rols says:

    Have had a psoas release following a hip replacement any advice?? Am engaging lateral hip flexors and tfl to compensate , body not happy!! Got about 1/3 of shredded psoas left

    • sbrsport says:

      Hi Rols, it really is difficult to comment without seeing you. My apologies, hope you come right.

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