What is the psoas?

The psoas major is a deep muscle running from the lower spine (around T12–L5) through the pelvis and attaching to the top of the thigh bone (femur). It joins with the iliacus to form the iliopsoas, one of the body’s major hip flexors.

It is particularly important for:

  • walking and running
  • lifting the leg
  • standing upright
  • stabilising the lumbar spine
  • stabilising the pelvis
  • coordinating movement between the spine and legs
  • helping us move from lying or sitting into standing.

It is essentially a deep central bridge between the upper and lower body.

✨ So why “muscle of the soul”?

There are several layers to that idea.

1. It is deeply connected to our survival response.

The psoas lies close to the sympathetic nervous system and structures involved in the body’s fight-or-flight response. When we perceive danger, the body prepares to run, fight or curl/protect itself. The psoas is involved in those physical responses.

This has led somatic practitioners to describe it as a place where the body can hold patterns associated with stress, fear and protection.

That’s where the spiritual language comes in: if the psoas is chronically contracted, the body can remain physically organised as though it needs to protect itself.

2. It is associated with the “fight, flight or freeze” posture.

Think about an animal sensing danger. It contracts its body ready to spring away.

Humans can develop something similar through prolonged stress — not because emotions literally become stored inside the psoas, but because the nervous system can establish persistent patterns of muscle tension and posture.

A relaxed psoas allows the hips and pelvis to move freely rather than constantly preparing for action.

3. It is at the body’s centre.

The psoas connects the spine, pelvis and legs, so it has an extraordinary influence on how the body organises itself around its centre of gravity.

That makes it a beautiful metaphor for:

Grounding, safety, movement and being able to move forward in life.

I can share a quick and easy way to balance this important muscle which can shorten with too much sitting down. Message me for your 60second fix!