Posterior Abdominal Wall and Pelvic Floor

Question 1

Diaphragm

Answer 1

O: Sternum - Xiphoid Process;
Coastal - T6-T12 Ribs;
Lumbar - L1-2/3

I: Central Tendon

N: Phrenic Nerve (C3-5)

A: Respiration (Drops with activation)

Question 2

Psoas Major

Answer 2

O: Bodies and Transverse processes of L1-5

I: Lesser Trochanter

N: Lumbar plexus L1-4

A: Flex thigh/hip, Lateral flexion of L/S, anterior pelvic tilt, trunk flexion

Question 3

Iliacus

Answer 3

O: Iliac Fossa

I: Lesser trochanter

N: Femoral nerve (L2-L4)

A: Flexes thigh/hip, anterior pelvic tilt

Question 4

Quadratus Lumborum

Answer 4

O: Iliac Crest (Posterior)

I: 12th Rib, transverse processes L1-L4

N: T12-L3

A: Unilateral - Lateral Tilt Pelvis; laterally flex spine

Bilateral - Extend spine, stabilize 12th rib during breathing

Question 5

Levator Ani (Puborectalis, pubococcygeus, and iliococcygeus)

Answer 5

O: Body of pubis, tendinous arch of obturator fascia, ischial spine

I: Perineal body, coccyx, anococcygeal ligament, walls of prostate or vagina, rectum and anal canal

N: Nerve to levator Ani (S3-4)

A: Forms most of the pelvic diaphragm that support pelvic viscera and resist increases to intra-abdominal pressure

Question 6

Ischiococcygeus

Answer 6

O: Ischial spine

I: Inferior end of sacrum and coccyx

N: Branches of S4-S5

A: Forms a small part of pelvic diaphragm that supports viscera, flexes coccyx