Main Muscles of Posterior Abdominal Wall

Question 0

Insertion of Psoas Major

Answer 0

By the strong tendon to lesser trochanter of femur

Question 1

Psoas Major Origin

Answer 1

Transverse process of lumbar vertebrael sides of bodies of T12-S1 vertebrae and intervening IV discs

Question 2

Innervation of Psoas Major

Answer 2

Lumbar plexus via anterior branches of nerves L2-L4

Question 3

Action of Psoas Major

Answer 3

Acting inferiorly with illiacus, flexes thigh; acting superiorly flexes vetebral column laterally to balance trunk; when sitting acts inferiorly with illacus to flex trunk

Question 4

Origin of Illacus

Answer 4

Superior two thirds of illac fossa, ala of sacrum, and anterior sacro-illiac ligaments

Question 5

Insertion of Illacus

Answer 5

Lesser trochanter of femur and shaft inferior to it and to psoas major tendon

Question 6

Innervation of Illacus

Answer 6

Femoral Nerve (L2-L4)

Question 7

Action of Illacus

Answer 7

Flexes thigh and stabilizes hip joint; acts with psoas major

Question 8

Origin of Quadratus Lumborum

Answer 8

Medial half of interior border of 12th rib and tips of lumbar transverse processes

Question 9

Insertion of Quadratus lumborum

Answer 9

Iliolumbar ligament and internal lip of illiac crest

Question 10

Innervation of Quadratus lumborum

Answer 10

Anterior branches of T12 and L1-L4 nerves

Question 11

Action of Quadratus lumborum

Answer 11

Extends and laterally flexes vertebral column; fixes 12th rib during inspiration