External oblique muscle

The external oblique muscle is a muscle of the abdomen that connects the lower eight ribs to the pelvis. It contributes to several functions including supporting the abdominal wall, assisting in forced expiration, raising the pressure in the abdominal cavity, and it assists in rotating the trunk.

Origin
The external oblique muscle originates from the anterior angles of the lower eight ribs.

Insertion
The external oblique muscle inserts on the outer anterior half of crest of the ilium and the inguinal ligament.

Innervation
The external oblique muscle is innervation by the anterior primary rami (T7-T12).