Muscles of Abdomen

Question 1

Rectus Abdominis

Answer 1

Origin: pubic crest
insertion: ribs 5-7 and xiphoid process
action: flexes vertebral column

Question 2

external oblique

Answer 2

origin: ribs 5-12
insertion: iliac crest and linea alba
action: -bilateral=compression abdomen and flexion of vertebral column
-lateral=lateral flexion and rotation

Question 3

internal oblique

Answer 3

origin: iliac crest, inguinal ligament, and linea alba
insertion: ribs 7-10, thoracolumbar, and fascia
action: same as external oblique

Question 4

transverse abdominus

Answer 4

origin: iliac crest, inguinal ligament, lumbar fascia, and ribs 5-10
insertion: xiphoid process, linea alba, and pubis
action: compresses abdoment

Question 5

quadratus lumborum

Answer 5

origin: iliac crest and iliolumbar ligament
insertion: ribs 12 and L1-L4
action: -bilateral=lumbar extension
-unilateral=lateral flexion