Muscles of Posterior Abdominal Wall

Question 1

Quadratus Lumborum (origin)

Answer 1

Medial half of inferior border of 12th rib, tips of lumbar transverse processes

Question 2

Quadratus Lumborum (insertion)

Answer 2

iliolumbar ligament, internal lip of iliac crest

Question 3

Quadratus Lumborum (action)

Answer 3

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

Question 4

Quadratus Lumborum (innervation)

Answer 4

Ventral rami of T12-L4

Question 5

Psoas Minor (origin)

Answer 5

T12-L1

Question 6

Psoas Minor (insertion)

Answer 6

superior ramus of pubis

Question 7

Psoas Minor (action)

Answer 7

posterior pelvic tilt

Question 8

Psoas Minor (innervation)

Answer 8

lumbar nerves 1 and/or 2

Question 9

Psoas Major (origin)

Answer 9

Bodies and transverse processes of all lumbar vertebrae

Question 10

Psoas Major (insertion)

Answer 10

Lesser trochanter of femur

Question 11

Psoas Major (action)

Answer 11

flex and laterally rotate hip, anterior pelvic tilt

Question 12

Psoas Major (innervation)

Answer 12

Lumbar nerves 2-4