<Tr> <Td_colspan="2"> Anatomical terms of muscle (edit on Wikidata) </Td> </Tr> <P> The psoas major (/ ˈsoʊ. əs / or / ˈsoʊ. æs /) (from Greek: ψόας - psóās:' of the loins', genitive singular form of ψόα - psóa' the loins') is a long fusiform muscle located on the side of the lumbar region of the vertebral column and brim of the lesser pelvis . It joins the iliacus muscle to form the iliopsoas . </P> <P> The psoas major is divided into a superficial and deep part . The deep part originates from the transverse processes of lumbar vertebrae I-V . The superficial part originates from the lateral surfaces of the last thoracic vertebra, lumbar vertebrae I - IV, and from neighboring intervertebral discs . The lumbar plexus lies between the two layers . </P> <P> The iliacus and psoas major form the iliopsoas, which is surrounded by the iliac fascia . The iliopsoas runs across the iliopubic eminence through the muscular lacuna to its insertion on the lesser trochanter of the femur . The iliopectineal bursa separates the tendon of the iliopsoas muscle from the external surface of the hip joint capsule at the level of the iliopubic eminence . The iliac subtendinous bursa lies between the lesser trochanter and the attachment of the iliopsoas . </P>

Where is the psoas muscle located and what is the action of the muscle