Rectus abdominis
O: pubic crest & symphysis pubis
I: cartilage of ribs 5-7 & xiphoid process
A: flexion of trunk
External obliques
O: lower 8 ribs
I: iliac crest & linea alba
A: flexion, lateral flexion, and rotation of trunk
Internal obliques
O: iliac crest & inguinal ligament
I: cartilage of ribs 9-12 & linea alba
A: flexion, lateral flexion, and rotation of trunk
Quadratus lumborum
O: iliac crest
I: 12th rib & transverse processes of L1-L4
A: lateral flexion & rotation of trunk
Psoas major
O: T12-L5
I: lesser trochanter of femur
A: flexion and lateral flexion of trunk
Iliocostalis
O: iliac crest, sacrum, ribs
I: ribs & C4-C&
A: extension, lateral flexion, & rotation of trunk
Longissimus
O: iliac crest, sacrum, C5-T12
I: transverse processes of C2-T12, lower 9 ribs, mastoid process of temporal
A: extension, lateral flexion, & rotation trunk
Spinalis
O: spinous processes of C7-L2
I: spinous processes of upper thoracic C2
A: extension, lateral flexion, & rotation of trunk