Origin:

• pubic symphysis and pubic crest

Insertion:

• xiphoid process

Nerve: inferior 6 intercostal nerves

Action:

• compresses abdominal cavity

Origin:

Insertion:

• linea alba

• pubic tubercle

• anterior ½ of iliac crest

Nerve: inferior 6 intercostal nerves

Action:

and lateral flexion

• Bilaterally: flexes trunk and compresses abdominal cavity

Origin:

• thoracolumbar fascia

• anterior 2/3rds of iliac crest

• lateral half of inguinal ligament

Insertion:

• linea alba

• pectin pubis

Nerve: inferior 6 intercostal nerves

Action:

• Unilaterally: ipsilateral rotation, lateral flexion

• Bilaterally: flexes trunk and compresses abdominal cavity

Origin:

• thoracolumbar fascia

• iliac crest

• lateral 1/3rd of inguinal ligament

Insertion:

• linea alba with aponeurosis of internal oblique

• pubic crest

• pectineal line

Nerve: inferior 6 intercostal nerves

Action:

• compression of the abdominal cavity

• support of viscera

Comments:

• Innermost of the 3 flat abdominal muscles

• Its fibers travel horizontally and end in an aponeurosis

Origin:

• iliac fossa

• iliac crest

• ala of sacrum

• anterior SI ligament

Insertion:

• blends with the psoas major to insert onto the lesser trochanter

Nerve: ventral rami of L1- L3

Action:

• Hip flexion

Origin:

• TVP’s L1- L5,

• sides of the bodies of T12 – L5 and respective IVDs

Insertion:

• lesser trochanter

Nerve: ventral rami of L1 – L3

Action:

• hip flexion

Origin:

• tips of TVP’s of L/S

Insertion:

• iliolumbar ligament

• internal lip of iliac crest

Nerve: ventral braches of T12 – L4

Action:

• Unilaterally: lateral flexion