going deep for the psoas

To be honest I have thought of the Psoas in a fairly mechanistic albeit vital sense. I have known that it is the long, strong,  muscle that connects the upper and lower parts of the body. Given its attachment to the top of the leg, specifically the femur at the lessor trochanter, I have thought it most likely plays a role as a hip-flexor (raising legs) and, in a lessor way, assisting the adduction of the femur (moving upper leg inward). We know that it is often implicated in chronic lower-back-pain, and releasing the psoas is something of a Holy Grail in advanced bodywork.


In Zenthai Shiatsu we use many techniques to invite the Psoas to release, from Dancing Shiva variations (bringing the lumbar spine into extension) to ‘swimming’ a soft hand to palpate the Psoas and illiacus directly. The Psoas seems to have a mind of its own and on a few occasions has given me a swift kick, as if to be saying ‘what on earth do you think you’re doing here?!’. So I’m keen to learn more, and its easy to find discussions about the Psoas; its something of enigmatic rockstar in the world of musculature.

My starting point are the web articles that have been doing the rounds on social media of late, mostly drawing on, or by, Psoas expert Liz Koch. There seem to be two particular strands to her psoas studies, or perhaps other therapists’ reaction to them, the first we might call energetic/emotional, and the second the physiological.


Liz Koch celebrates the the Psoas as an energetic and emotional muscle with a unique status. She claims that in embryonic formation, a ‘primitive streak’ emerges in the midline of the foetus. The Psoas is a primary emergence from this streak and is a messenger ‘of the nervous system; integral to primary reflexes, neurological proprioreception, and personal integrity’. Elsewhere she describes it as as the muscle of the soul, and the guardian of the dan tien. Shiatsu therapist Dan Stretton describes the Psoas as the thirteenth organ, ‘energetically it would not be too bold to say that its movement creates the ability of organism to progress through its life at all levels’. 

My favourite anatomist Tom Myers sees it as part of his ‘deep front fascial line’ – with the lower fascia of the diaphragm connecting with the upper fascia of the Psoas. This intersection is just behind the kidneys, adrenals and solar plexus and just in front of the thoracolumbar junction (TLJ); the meeting of lumbar and thoracic vertebra. Not only is this solar plexus area the locale of gut reaction but it is thus the interface of the upper and lower body, establishing an essential relationship between breathing and walking, assimilation and elimination (see Tom Myers, Anatomy Trains pg 190-194).

So how should the Psoas be thought of in 5 element meridian terms? Ones first thought is that it is deeply connected to the Kidney Meridian, and when Tom Myers talks about the connection between assimilation and elimination we are talking Metal Element. While this may be true, Dan Stretton notes that Psoas is an emergence of Chong Extraordinary Vessel, and this is consistent with Liz Koch’s take that the Psoas comes from the central embryonic streak (equivalent to the Chong). The Psoas indeed runs alongside the Chong into GV4, where the Belt Vessel joins the back and front of the body from GV4 to CV6. The Psoas is no ordinary muscle so its no surprise that’s its on an extraordinary vessel. Being  part of an ‘extra’ vessel means that excesses from other meridians can be channelled into it, or it can be drawn upon to tonify the ‘ordinary’ meridians. In a sense the Psoas is a healer in itself and perhaps we need to see it as a partner in rather than a subject of therapy.

Note to self and those wishing to experiment. Briony comments that it would be very interesting to try treating the opening and closing points on the Chong and Belt vessels for Psoas related back problems. Opening points for the Chong are Spl4 and closing Peri6 and the Belt opening point GB41 and closing point TH5. Usually only one side is treated, test opening points to see which side softens pulse, same with closing points and then hold the two points, touching opening first and then closing, holding lightly for a few seconds. Take your hand off the closing point last. You can learn how to do this accurately with Greg Williams of Qi Art Therapies in Brisbane.

It is also interesting to note that our Yoga Asanas for treating the Psoas have been Earth Element orientated. We thus often recommend Warrior series for extending the the Psoas (see detail on this below). The Chong opens with an Earth Point and is all about our connection to Source Ki, Mother Earth. The lunges in Warrior series we have thought useful to alleviating the shortening of the Psoas by prolonged sitting, but if we think in terms of the Chong, then strong standing poses and walking on the earth is as much an energetic as physical treatment. The pendulum movement of the psoas when walking is a bit like a metronome, keeping our rhythm on Earth? Stretching or extending the Psoas is controversial so I want to return to the question of treatment when we have looked more closely at the Psoas physiology.


Liz Koch has broken ranks with the anatomical tradition and antagonistically declared, ‘the Psoas, is not a hip flexor’!. She argues that Psoas doesn’t contract to flex the hips, but rather draws back towards the spine:

Even within the biomechanical model, it is worth noting that the psoas exerts an eccentric contraction, which is a confusing way of saying that the psoas doesn’t shorten. Rather it falls back along the spine while lifting the legs, bringing knee to chest, curling the spine, or bending at the hips. During walking, the psoas moves like a pendulum through the core maintaining its full length as the leg swings forward and back. Liz Koch 2009

Liz Koch is being deliberately antagonistic (later she acknowledges the lower Psoas might be viewed as a hip-flexor) because she’s wants to change the common mechanistic attitude towards it, that is, if we see it as a flexor then we are going to try to stretch and strengthen it to remedy it. She would prefer us to see it as a sentient emotive structure that we nourish and get to know using an active relaxation technique, simply lying on our backs with our knees bent, and feel the ‘deep neutrality within the core’ of our bodies. Liz Koch sees the Psoas therapy as a personal journey for its owner to undertake, and is not keen on manual manipulation of the Psoas complex.

Tom Myers also notes that lumbar neutrality is essential in the lumbar before we begin start extending hips. He observes, however, that we can work the Psoas directly, we just need to understand its complexity as a both a hip flexor and extensor. More specifically Myers argues that the upper Psoas performs as a lumbar flexor, while the lower Psoas acts a lumbar extensor. Let’s take a look at this in more detail.

Tom Myers describes three functional fascial lines of the Psoas. These are shaped in a triangle with a long ‘express line’ (like an express train) in the middle and shorter sets of ‘locals’ (stopping at anatomical stations) an either side. The first express or middle line of the Psoas Major is well known: from the bodies and transverse processes of first lumbar and sometimes the 12th thoracic vertebrae and onto the lessor trochanter of the femur. The second track or inside line and first set of ‘local stations’ is on the inside of the Psoas major: starting at the 12th thoracic veterbrae, down the psoas minor to join with the lucanar ligament of the pubis then onto the pectineus and again, also attaching at the lessor trochanter. The third track, lateral set of locals or simply outside line starts with the attachments of the quadratus lumborum to the 12th rib and lumbar veterbrae attaching to iliac fossa of the hip and continuing onto the iliacus and attaching, once again, at the well populated lessor tranchanter.

A key aspect to treatment therefor is discerning if the client has a anterior or posterior tilt of the lumbar spine, is there a tilt or imbalance between right and left, and third make a decision as to which line we need to work on. A useful test here is to move between straight legged hip extension (like Warrior 1 on the ball of the foot) to feel into the outer set of locals, and a medially rotated hip extension (think Warrior 2 with the back foot at 45 degrees) to give awareness to the inner set of locals. I found this counterintuitive at first (medial rotation is accessing lateral line) but started to make sense as I practiced it.

To finish I want to think a little about my Psoas techniques in a Zenthai session. As mentioned the upper psoas and the long middle express line I am starting to see in Liz Koch’s way — as a sacred tendinous highway, with powerful energetic qualities. We need treat carefully, emotional and energetically, use tonification and active resting techniques, and try the distal release points on the Extraordinary Chong and Belt Vessels. More work is needed for these noninvasive techniques, at least for my practice.

If we are going to work actively on the muscle itself perhaps using a gentle pulsing technique like this one from Christopher Sovereign is best, particularly for the long middle track. This involves creating a pulsing/rocking motion from the knee and allowing the knuckles to sink gently through the abdominal fascia. Having used this technique a few times in last week I am yet to traumatise a wary and weary Psoas. Its worth noting that in a Tom Myers Structural Integration, the therapist will not address the Psoas until well into series of treatments, releasing superficial fascial lines before the Psoas, and the rest of the Deep Front Line.

The local inside and outside line are made of softer muscle tissue, and according to Tom Myers, are better suited to manipulation than the tendinous abdominal Psoas major of the middle line. For the inside line try having the client in supine with a knee bent as Tom Myers suggests or work the upper adductors from side position. For the outside line Kaline’s side position may be fine for some clients, supine with legs bent is better for others. I know Monique is particularly adept at this outside line in side position.

In Dancing Shiva we need to take Gwyn’s cautions seriously: if in side position make sure you are not bringing the lumbar spine out of neutrality, get the client to hug the lower knee to chest for clients with any excessive lumbar extension, or if the client is in prone gently lock the sacrum or butt-crease with your foot before carefully extending the hip? We need to work purposefully here, bring our intention to the outside or inside line of the psoas with a gentle rotation of the hip joint.  I am starting to appreciate that this is often gentle fascial work rather than stretching the muscles fibres.

Post script

In mice the Psoas is apparently made up primarily of fast-twitching muscles (see Psoas wiki); it is made for rapid contraction pumping inward toward the spine as the animal runs. As Tom Myers observes in quadrupeds the Psoas takes a comfortable route clear of the pelvis but in humans it has had to take a radical journey around the front of the pelvis, and perhaps we could say its function has differentiated, with more of a static balance and connective purpose. The study cited in wiki also found that in us bipeds the Psoas comprises a mixed balance of fast and slow twitch muscle fibers. In light of what has been theorised from Anatomy Trains, ie the three different fascial lines of the Psoas complex, it would be really interesting to know if the ratio of slow to fast twitch muscles is higher in the middle line and lower in the shorter outside lines. This would add some biological grounding to the great work of Liz Koch.

1 Comment

  1. andrew on 26 July, 2013 at 11:46 pm

    Hmm. Psoas. Always amazed that beyond the anatomy the traditional practice Ampuku picks up all aspects of Psoas (and abdominals). Such a simple practice working in such an intelligent way…

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