Iliopsoas Iliacus also is known as the iliopsoas(Iliopsoas Iliacus + Iliopsoas Psoas major). this refers as two muscles which are separate in the abdomen but merges while inserted and thus known as the joint iliopsoas. Origin of the iliopsoas Iliopsoas originates from iliac fossa & crest, lateral sacrum separately. Iliopsoas Psoas major Originates from transverse processes of L1-L5, bodies & discs of T12-L5. Insertion of the iliopsoas The iliopsoas is inserted on the lesser trochanter of the femur as one tendon. The action of the iliopsoas The iliopsoas( Iliopsoas Iliacus + Iliopsoas Psoas major ) is the prime mover of thigh flexion.iliopsoas is also responsible for lateral flexion of the vertebral column(psoas). Nerve Supply of the iliopsoas The iliopsoas is supplied with Femoral nerve (L2-L4) (Iliacus), Anterior rami of sacral plexus (L1-L3 ) (Psoas major). Ili...