The external oblique is a muscle of the anterior abdominal wall. It is the largest and most superficial of the flat abdominal wall muscles.
- Attachments: Originates from ribs 5-12 and inserts onto the iliac crest and pubic tubercle.
- Actions: Contralateral rotation of the torso.
- Innervation: Thoracoabdominal nerves (T7-T11) and subcostal nerve (T12).
- Blood supply: Lower posterior intercostal arteries, subcostal artery, deep circumflex iliac artery.