Unpacking the fascia- Psoas fascia

(From Human anatomy and physiology, Marieb & Hoehn)

The psoas fascia covers the entire psoas muscle, it is continuous with the medial arcuate ligament of the diaphragm, the iliac fascia while also contributing to the femoral sheath at its distal end. Laterally the psoas fascia will continue as the thoracolumbar  (T.L) fascia which will cover the quadratus lumborum muscle. The importance of the psoas fascia lies in the structures that surround it and therefore be influenced. In the organ field the kidney and ureter are two organs that are intimately close to the psoas fascia so much so that the renal fascia anchor itself to the psoas fascia. We could think of how the psoas fascia could compensate for forces and mechanically influence the kidneys, but there are also the adrenal glands situated atop the kidneys that are a crucial part of the hormone axis of the body and brain. Now the psoas fascia has an important role related to the ability for the adrenal glands to function adequately. Mechanical changes to the psoas fascia can impact the ability for the kidneys and ureter to function, large forces in psoas can risk impinging the ureter creating difficulty in urination. The psoas fascia is an important structure for the modulating systems of the body not only through the adrenal glands, but also through the proximity to the lumbar sympathetic chain ganglia. The communicating branches situated directly after the intervertebral foramen traverse between the vertebrae and psoas fascia to reach the sympathetic chain along the anterior medial border of psoas. As the psoas fascia compensates for forces on the muscle, its pulls on the attachments along the transverse processes of the lumbar spine. This can impact the space allocated for the communicating branches to travel and may distort the message being sent to the lumbar splanchnic nerves. The psoas fascia blending with the medial arcuate ligament of the diaphragm creates an interrelationship between the motion capabilities of the psoas muscle and the thoracic diaphragm. From this standpoint, the psoas fascia can be used as leverage to the diaphragm, same being true for its connection inferiorly into the thigh. The psoas fascia contributes to the inguinal canal allowing passage for the genito-femoral nerve to the spermatic cord / round ligament.