The Athlete’s Guide to the Psoas Muscle

by Mobility Athlete · Published September 13, 2021 · Updated January 25, 2022

For a muscle that’s critical to your athletic ability, the psoas muscle hardly gets enough attention.

This article will break down what the psoas muscle is, what it does, how it affects your athletic performance, and some of the ways you can tell if you have a tight psoas muscle limiting your athletic potential.

What Is the Psoas Muscle?

In simple terms: The Psoas Muscle (pronounced ‘so-as’) connects your torso to your legs.

In technical terms: The psoas major starts from the lumbar vertebrae and wraps around the sides of the pelvis, then connects to the femur. It also combines with the iliacus muscle, and together they form the iliopsoas muscle.

To help create a mental image, the human psoas is like the animal equivalent to the tenderloin.

What the Psoas Does

The psoas flexes the hip joint and allows you to lift your upper leg towards your body. Without it, you wouldn’t be able to walk, let alone run or sprint.

Anything that involves movement of the upper leg and flexion of the hip joint is made possible by the psoas.

When you combine a strong, flexible, and healthy psoas with the supporting muscles of your core, it leads to stabilization of your entire midsection.

How the Psoas Affects Athletic Performance

It doesn’t matter if you’re sprinting, playing basketball, or chasing your kids around the yard. It’s hard to think of many athletic movements that don’t involve proper upper leg movement.

Every time you run, you rely on the psoas to contract to lift the leg and then lengthen as your leg extends behind you to propel you forwards.

Having the ability to lengthen your running stride is one of the easiest ways to improve your running speed and efficiency.

A healthy psoas can also have a significant impact on your breathing. If your psoas muscle is tight, you can thrust your ribcage forward, causing shallower breathing through the chest instead of proper, full breathing range of motion.

If you have a weak or inflexible psoas muscle, you deteriorate arguably the most essential aspect of your athletic ability – human propulsion. Notable athletes like David Goggins have discussed at length how opening up a tight psoas fundamentally changed their athletic performance.

How to Know if You Have a Tight or Weak Psoas

If you suspect an injury, feel any form of pain, or have significant immobility, you should always begin by talking with your doctor or preferred healthcare professional right away.

Psoas tightness is common. One of the simple causes is from sitting for long periods of time. When you sit, your hips flex forward and shorten the psoas. Over time, your body adapts to the new shortened length.

The result? A shortened and tight psoas muscle.

If you feel tightness in the hips when you walk or experience what I like to call “the runner’s shuffle,” chances are it may originate from a tight psoas muscle.

In more pronounced scenarios, a short and tight psoas could also play a part in anterior pelvic tilt, which, simply put, is your hips tilting inward toward the front of your body.