I am looking to get on a bit of a roll here…as long as I don’t get exhausted again I should be able to manage it! Robert Johnston (the Principal with Principles) speaks about his myogonal theory to students of the CAO and there are certain muscles that have a lot of functional anatomical connections which end up being very important to an Osteopathic Operator. Within Mr. Johnston’s myogons, the lower/base myogon is very much affected by the psoas. My goal right now is to highlight some of the major functional anatomical conections with the psoas and start to speak about why using the psoas is so powerful in treatment.
First and foremost, the psoas attaches to the transverse processes, the vertebral bodies, and the intervertebral disks of T12-L5 as well as the lesser trochanter on the medial aspect of the superior femur. The psoas, along with the quadratus lumborum, forms the posterior abdominal wall. The posterior abdominal wall is the attachment point for the peritoneum (think about that – the connective tissue that surrounds the organs ties in to the psoas and QL). The psoas passes through the medial arcuate ligament of the diaphragm which shows a very close connection between the psoas and the diaphragm. The kidneys are fused to the psoas via the connection between the psoas fascia and the renal (Gerota’s) fascia. The lumbar plexus is closely associated with the psoas as all of the nerves must pass it in some way (whether anterior, posterior, lateral, medial, or directly through).
Before I continue forward I want to speak about Osteopathy in the visceral field. There seems to be some interesting ideas as to what this entails and a very unique focus on attempting to alter the position of the viscera if they are tested to have an inspir or expir lesion. Considering the attachment of the peritoneum to both the quadratus lumborum and the psoas it does not seem to make sense to even test for inspir or expir lesions without first correcting the psoas/QL/pelvis. The viscera are supported and surrounded by the peritoneum. The peritoneum attaches to psoas and QL. The logic seems pretty simple here…correct the psoas/QL to ensure that they are not altering the position of the viscera before even checking them – this is differential diagnosis. If the psoas has been corrected and there is still a visceral lesion then it makes sense to test and correct.
Continuing on with the psoas, the relationship between the leg/pelvis/lumbar vertebrae the psoas provides a huge opportunity to interact with all of these structures by using the leg as a lever. It should be clear that due to the size of the psoas as well as the multitude of attachments it carries between T12 and L5 that it is the most influential muscle in the lower myogon and definitely the most influential muscle for the lumbar vertebrae. The psoas is also the direct line between the lumbar vertebrae and the femur which should make it clear that using the leg as an available lever is the most effective option to correct both the leg and the lumbar vertebrae.
As I said in my previous post, it is important to set the base before treating other structures and the base is the pelvis. Using the leg as a lever will allow for correction of the innominates as well as coordinate the leg/pelvis/lumbar vertebrae to level the base. Also, before correcting the thoracic/dorsal vertebrae and the thoraco-lumbar junction it is imperative that the lumbar vertebrae be functionally level/neutral so that the structures above may be adjusted appropriately and meaningfully.
The psoas is so anatomically dense that it is likely the most meaningful muscle to interact with as an Operator. It can be suggested that our current societal circumstances (sitting the majority of our days instead of being upright and mobile) is highly related to our altered health status compared to previous generations. Through sitting for long periods of time our psoas is not used to mobilize our viscera and alter pressure gradients through them to promote function generally and drainage specifically. The psoas is highly related to the kidney and, as such, if it is not working as it is intended there is a much higher possibility for stagnation of fluid globally as the function of the kidney will be altered.
There is no particular need to continue rambling…it is painfully obvious that the psoas is extremely important to the leg, pelvis, lumbar spine, lumbar plexus, abdominal viscera, the peritoneum, the thoracic/respiratory diaphragm, the thoraco-lumbar junction, and much more – BECAUSE FUNCTIONAL ANATOMY SAYS SO!