Muscle
External oblique
Outermost flat abdominal muscle
High-yield
Fibres run "hands in your pockets"; its aponeurosis forms the inguinal ligament. Rotates trunk to the opposite side.
Overview
The largest and most superficial flat abdominal muscle, its fibres running inferomedially ('hands in pockets'), forming the inguinal ligament inferiorly.
Reference facts
- Origin
External surfaces of ribs 5–12
- Insertion
Linea alba, pubic tubercle, and anterior half of the iliac crest
- Action
Compresses the abdomen; flexes and rotates the trunk to the contralateral side
- Innervation
Thoracoabdominal nerves (T7–T12) and subcostal nerve
- Blood supply
Lower posterior intercostal / subcostal arteries