One unique muscle has influence over most physiological processes in the body. That would be the Thoracic Diaphragm and it’s many fascial LINKS.
The thoracic diaphragm (picture 1 in blue, 1 in picture 2) is a wide flat muscle that attaches to vertebrae and ribs but it’s vast soft tissue connections are most interesting.
One example of many is the Thoracic Diaphragm’s effect on the psoas and the quadratus lumborum via direct fascial LINKS. Specifically, the diaphragm has specialized “fascial doors” called Arcuate Ligaments to allow for the psoas (medial arcuate, blue) and QL (lateral arcuate, green) to pass through it and attach to the spine and 12th rib (picture 2). These links assure respiration’s direct effect on psoas/QL tension. In addition, the diaphragm tissue is continuous with the Fascia Iliaca or the inner skin of the psoas (picture 1 in pink) which establishes a continuity of the diaphragm to the legs. This orthopedic connection is only a few in addition to many visceral, neural and vascular links for the thoracic diaphragm.
One could say it is nearly impossible to have a function in the body that doesn’t have at least an indirect LINK to the diaphragm and respiration.
Credit: @anatomylinks
