Psoas MajorThe structure indicated is the psoas major muscle The psoas major muscle is one of the muscles which makes up the posterior abdominal wall. There are four muscles which contribute to the posterior abdominal wall:
- Psoas major
- Psoas minor
- Quadratus lumborum
Origin: Transverse processes of L1-L5, vertebral bodies and discs of T12-L5
Insertion: Lesser trochanter of femur
Action: hip flexion, lateral rotation of thigh
Innervation: fibres of L1-L3 of lumbar plexusLearn more about the muscles of the posterior abdominal wall in this tutorial.