Muscles

Question 0

Psoas Minor

Answer 0

May be absent
Origin: Sides of bodies of T12-L1
Insertion: pecten pubis, iliopecten eminence, and iliac fascia
Innervation: ventral ramus of L1
Action: weak flexion of trunk

Question 1

Psoas Major

Answer 1

Origin: transverse processes of lumbar vertebrae, sides and bodies of T12-L5
Insertion: lesser trochanter of femur
Innervation: ventral rami of L1-L3
Action: Flex trunk and thigh, lateral flexion of vertebral column

Question 2

Quadratus Lumborum

Answer 2

Origin: medial inferior border of 12th rib and transverse processes of lumbar vertebrae
Insertion: Iliolumbar ligament, inner lip of iliac crest
Innervation: ventral rami of T12-T4
Action: extend and lateral flexion of vertebral column, fix 12th rib during expiration

Question 3

Iliacus

Answer 3

Origin: upper 2/3 of iliac fossa, sacrum and anterior sacroiliac ligament
Insertion: lesser trochanter and anterior to it with psoas major tendon
Innervation: femoral nerve
Action: flex thigh, stabilize hip joint