Internal Oblique
Abdomen & Core
Fibers run opposite to external oblique — together they create a natural corset.
Function
Rotates trunk ipsilaterally, flexes trunk, compresses abdomen
Origin
Thoracolumbar fascia, iliac crest, inguinal ligament
Insertion
Ribs 10-12, linea alba, pubic crest
Innervation
Intercostal nerves T7-T12, subcostal, iliohypogastric, ilioinguinal nerves