Muscle Review: The Psoas!

Do you have a favorite muscle?! I do! It’s the psoas – pronounced ‘so-az’.

So, what?

So, your “psoas” is actually two muscles, the psoas major and the psoas minor. These two

muscles grouped together are your deepest core muscles as they are found beneath your

abdominal muscles. The psoas originates from the lumbar vertebrae (L1-L5) and runs along side

the spine and then joins the iliacus muscle (which lines your pelvic bowl). The two form the

commonly, and incorrectly, termed “iliopsoas”, which attaches at the lesser trochanter of the

femur (think upper, upper, inner thigh bone). It is the only muscle that connects your spine to

your legs!

Contrary to popular belief, the psoas muscle is not solely a hip flexor. Yes, it is involved

in drawing the torso and leg closer together, however it serves many more core stabilizing

functions. When the psoas is healthy and pliable, it allows the leg to swing freely as you walk or run. The psoas also counters the muscles surrounding and supporting the lumbar spine in your lower back. In this way it keeps you upright and assists in healthy posture. As you twist, turn or lean your psoas supports and stabilizes your side-to-side motions. It plays major roles in flexibility and range of motion, core strength, organ and nerve function, and breathing!

It should be noted that the psoas works by eccentric contraction; it lengthens (rather than

shortens) along the front spine upon contraction. In many individuals the psoas is restricted or tight. Overworked or weaken muscles may result in poor posture and alignment that requires the psoas to be continuously worked and unable to relax. Misalignment and tension restricts proper movement and function of the psoas, contributing to compressed organs, nerves and circulation for blood and lymph. Constant strain at the psoas can be a major factor in lower back pain, sciatica, scoliosis, hip/knee/ankle tension and misalignment, increased menstrual pain, and digestive and bladder problems.

Pilates instructor and psoas enthusiast Liz Koch (she has been singing praises of and

teaching about the psoas for over 30 years) highlights why it is so essential to maintain a healthy psoas:

It tells a story about an essential midline called the primitive streak from which

everything emerges. Within this paradigm the psoas grows out of the human midline and is a

messenger of the central nervous system; integral to primary reflexes, neurological

proprioception, and personal integrity.

- Pilates Digest, September 8, 2009

So, now that you know all about the psoas, I know you’ll want to keep it healthy. Check

out the following websites for information and some insight as how to keep your psoas in

optimal condition:

How to Stretch and Strengthen the Psoas

The Runners Guide to the Psoas

Psoas and Your Back & Psoas Stretches

3 Myths About the Psoas

The Psoas: The Muscle of the Soul

PSOAS