Muscles of Post Abdominal Wall

Question 0

iliacus

Answer 0

O: sup 2/3 of iliac fossa, ala of sacrum, and ant sacro-iliac lig
I: lesser trochanter of femur and shaft inf to it
psoas major tendon
N: femoral nerve (L2-L4)
A: flexes thigh and stabilizes hip joint

Question 1

psoas major

Answer 1

O: transverse processes of lumbar vertebrae
sides of bodies of T12-S1 and intervening IV discs
I: lesser trochanter of femur by a strong tendon
N: lumbar plexus via anterior branches of L2-L4
A: acting inf w/ iliacus– flexes thigh
acting sup– flexes vertebral column laterally to balance trunk
when sitting– acts inf w/ iliacus to flex trunk

Question 2

quadratus lumborum

Answer 2

O: med 1/2 of ant border of 12th rib
tip of lumbar transverse processes
I: ililumbar lig and internal lip of iliac crest
N: ant branches of T12 and L1-L4
A: extends and laterally flexes vertebral column
fixes 12th rib during inspiration