To understand your psoas muscles means to understand what they do when healthy, and the symptoms, when they are unhealthy (too tight).

What Your Psoas Muscles Do

In healthy function, your psoas muscles maintain your uprightness in sitting, influence your spinal alignment and balance when standing, and your movement when bending, twisting, walking and running. Your psoas muscles are core stabilizers.

Tight psoas muscles show up as groin pain, deep pelvic pain, and as a deep belly ache. Postural effects include a butt that sticks out in back and a protruding belly, as your pelvis shifts position to top-forward. In movement, stride length is restricted.

Tight hamstrings often develop to compensate for the extra drag. Chronic constipation also develops, in some people, due to the effect of an overactive psoas on the neighboring nerve plexus that regulates intestinal activity.

To Free Tight Psoas Muscles

Three basic approaches exist.

  • stretching
  • massage / manipulation
  • movement training

First basic understanding: Muscle / movement memory runs the show.

If your psoas muscles are tight, your muscle / movement memory keeps them that way. Muscle / movement memory comes from a defect level of the nervous system than voluntary movement does; it's conditioning.

Because muscle / movement memory develops by conditioning, stretching and manipulation produce, at best, temporary and partial results. You can not stretch or manipulate away conditioning; you can not stretch or manipulate away muscle / movement memory. The pattern of remembered movement and tension quickly returns. That understanding explains your experience with therapy for tight psoas muscles.

Since muscle / movement memory runs that show, you need an approach that re-conditions muscle / movement memory – and that's where movement education comes in.

Movement education is not “knowing how to move” or “maintaining good posture” or maintaining “neutral spine position”. It's new, automatic movement conditioning. It lives at the depth where motion / memory exists – the kind of movement memory involved in riding a bicycle, for example.

How did you learn to ride a bicycle (or swim, for that matter)? Practice: development of new patterns of movement until they become habitual.

To develop new control and new movement involves not just free muscles, but also integrating them into movement patterns with other movers and stabilizers of the body.

Movement training also involves awakening sensation of movement and position. The odd thing is, if you do not have such sensation or if it's distorted, you do not know it. It's an absence. When you develop such sensation, you realize what you had lacked.

Without the integration step, your psoas muscles are likely to revert to their tight state. I'll say more, as we go on.

Understanding how psoas muscles play in movement simplifies our approach to setting things right. Having made such a statement, I will, of course support it. But first, I have to lay some groundwork.

“PSOAS” OR “ILIOPSOAS”?

The psoas muscles share a common tendon and end-point with the iliacus muscles, which line the inside of the pelvis, so the combination is called, the “iliopsoas” muscle. For brevity, I use the term, “psoas muscle”.

CORE MUSCLES

The psoas muscles are our deepest core muscles.

When people speak of the “core”, they usually mean the muscles of the abdominal wall. But how is that the “core”? The core of anything, such as the Earth or an apple, is its centermost part. The psoas is a core muscle (as are the diaphragm, quadratus lumborum, iliacus and other muscles closest to bone); the abdominal muscles are “sleeve”, outside the core.

HOW CORE FUNCTIONS

The psoas muscles, being most centrally located as the deepest muscles in the body, help control the shape of the spine. By controlling the shape of the spell, they control our balance – how the centers of gravity of our major segments – head, thorax (or chest), abdomen and legs – line up.

Tight psoas muscles distort the spiral curves, shorten the spell, change pelvic balance and cause ungainly (chunky, heavy, labored, awkward) movement. To the degree that the spiral curves are removed, our alignment is distorted and to that degree, we are out of balance and our movement is un-economic / wasteful of effort.

COORDINATED MUSCLE / MOVEMENT MEMORY

Muscles never work alone; they always work in concert with other muscles. What any muscle does affects our entire balance. Other muscles have to compensate for those effects on balance by tightening or relaxing. Your brain controls these entire patterns of movement and compensation with memories of movement (“muscle / movement memory”).

Because your nervous system and muscular system cooperate as a whole, to try to change the movement and tension behavior of tight psoas muscles without changing the larger movement pattern of which they are a part is to work against the rest of the system and its (our ) memory of how movements go and feel. That's why methods of muscle manipulation (eg, massage, myofascial release, stretching) produce changes that are either temporary or slow in coming – and because muscle release by manipulation is painful: it works on sore, contracted muscles directly against the condition of the entire movement system, which resists the change.

ACVITITY AND REST: COORDINATION AND MUSCLE TONE

The term, “tone”, refers to the level of muscle tension: complete rest means zero muscle tone; complete activation means maximum muscle tone. Some people believe that the higher the tone, the better; others believe that complete relaxation is better. As you will see, where tone is concerned, it's either; better-integrated is better, and better-integrated means more freedom to adjust accurately to changing conditions – freedom and balance.

Your brain coordinates the movements and tone of muscles; tone changes as position changes in movement. That's what is meant by “supple.” Supple psoas muscles have the sensation of spaciousness, support, freedom and length at your body core. The term rolfers use is, “open core.” When psoas muscles do their job of stabilizing the spine, they relate the abdominal wall muscles of some of that task; your abdominal muscles have the sensation of relaxation and free breathing. The term rolfers use is, “free sleeve.” Healthy functioning of the musular system gives the experience of “open core, free sleeve.” Open core / free sleeve is the feeling of trunk / spine length, flexibility and stability.

HEALTHY FUNCTION

“Healthy”, in this sense means, “getting the intended result with the least effort.” Where movement is concerned, the word, “graceful”, applies. Graceful movement is economic movement; awkward movement is uneconomical or ungainly movement. Graceful movement preserves effort; ungainly movement wastes effort. For movement to be economic, it must be well-balanced and well-coordinated – a matter of integration.

Psoas muscles help regulate our changes of position as we move from rest into activity and from activity into rest by changes in their tone. They help maintain balance and stability in those positions. They are central to movements from lying to sitting, from sitting to standing, and from standing to walking and running. If their tone is too high, they interfere with balance and stability as we move into different positions; their tone is almost never too low, and if so, usually indicates either neurological damage or a need to learn basic control.

With changes of position, the activity level of the entire muscular system muscles changes, as follows.

From Lying Down to Sitting to Standing to Walking and Running

At rest or in repose, your psoas muscles have no job to do and should be at rest – which means relaxed and comfortable.

Your psoas muscles connect your legs to your trunk. When you move from lying to sitting, they provide a sufficient stable core to move to the upright position.

Overly tight psoas muscles create groin pain or deep low back (lumbopelvic) pain when changing position from lying to sitting. You may have the experience of a groin pull or of muscles seizing up in your pelvis.

When Sitting – Psoas muscles connect groin to pelvis and low back and stabilize balance in the front-to-back direction and to some degree, in twisting movements; your brain adjusts their tone for the right amount of front-to-back stability under the pull of gravity.

From Sitting to Standing – As you move from sitting to upright standing, your psoas muscles must relax and lengthen to permit you to stand fully upright.

Overly tight psoas muscles, which connect your groin to your spine, prevent you from coming to a fully erect, balanced position.

When Standing – Well-regulated tone is low enough to allow you to stand at your full stature, with minimal lumbar curve and high enough to stabilize your balance. Through your psoas muscles, your brain adjusts your spiral curves (and balance) as you bend forward, lean back, move side-to-side, and twist and turn.

Overly tight psoas muscles do not lengthen enough as you stand straight; they pull from your groin to your low back, causing lumbopelvic or lumbosacral pain, a “pubes back” position, and excessive lower back curve. Your belly protrudes and your butt sticks out.

From Standing to Walking – As you step into walking, you first shift your weight onto one foot to free the other leg to come forward; the psoas muscles on the standing side relax and those on the walking side tighten to help you step forward. In healthy walking, your psoas muscles freely alternate, side-to-side, between higher and lower tone as you walk or run.

You can not make a repeating change in one muscle group without changing the rest of your movement system because your brain fulfills habitual patterns of movement among muscles (pattern of coordination); to change one, you have to reorganiz the entire pattern. That kind of change does not occur “by deciding to move differently”; when you're walking, you can not conveniently put that kind of attention into your movements; you have to make it automatic, and there's a process for that, mentioned below.

SUMMARY

Efforts to free the psoas muscles without also improving their coordination with the rest of the musculature produce only partial and temporary improvements.

That means that “psoas release” techniques, “psoas stretches”, and psoas strengthening approaches need movement education (which involves brain-muscle training) to produce a stable shift to healthy psoas functioning.

Economical movement (least effort, good result) and easy balance are the goal – attributes you can develop by movement training that first frees the psoas muscles and then integrates them into economic movement patterns. First free, then integrate.

It's convenient to use the movements and positions in which the psoas muscles participate – from repose to sitting, from sitting to standing, from standing to walking (and by extension, to bending, twisting, running and other actions) – to evaluate them functioning and to free and integrate them.

Then, it's a brain-level training process that changes the brain's sense of movement and coordination.

One name for that kind of training process is, “somatic education.” Learn more, below.