Human Movement Science & Functional Anatomy of the:

Psoas

by Brent Brookbush MS, PES, CES, CSCS, ACSM H/FS

Psoas Image – Gray’s Anatomy 20th Edition via Bartleby.com

Anatomy:

    • Origin: Ventral surfaces of the transverse processes of all lumbar vertebrae, sides of the bodies and corresponding intervertebral disks of the last thoracic and all lumbar vertebrae, and the membranous arches that extend over the sides of the bodies of the lumbar vertebra (11)  Occasionally reference is made to a psoas minor with and origin on the vertebral body of T12 and fusing with the psoas major approximately the level of the femoral head.  The psoas minor is not present in everyone.
    • Insertion: Lesser trochanter of the femur

      • The psoas is bordered posteriorly by the deepest layer of the thoracolumbar fascia and quadratus lumborum, enveloped by fascia arising from the deep layers of the thoracolumbar fascia, and abutting the peritoneum anterioly.  The superiorly the fibers of the psoas extend past the diaphragm and invest in the arcuate ligament and inferiorly they pass just anterior the pubic ramus, posterior to the inguinal ligament and lateral to the fascial structure known as the iliopectineal arch.
      • Palpating the psoas major is a skilled palpation.  With your partner lying supine, flex their hip and knee into hook-lying (crunch) position.  Place your leg under their leg so they can completely relax.  With finger pads over finger pads palpate an inch or so medial to the ASIS (between naval and ilium).  Allow your fingers to slowly depress in the direction of the lumbar spine (slight medial inclination) as they exhale.  Make small gentle hook like motions to help overlying