MuscleAbdominal wall — anterolateral

External oblique

Latin: M. obliquus externus abdominis sinistra

Location: Abdomen

Paired structure: one on the left and one on the right side of the body.

View the external oblique in 3D

Origin

External surfaces of ribs 5–12, interdigitating with serratus anterior and latissimus dorsi.

Insertion

Iliac crest, pubic tubercle, and into the linea alba via the aponeurosis folding to form the inguinal ligament.

Action

Compresses the abdomen and, acting unilaterally, rotates and side-bends the trunk to the opposite side; the sailing and baseball-swing muscle.

Nerve supply

T7–T12 thoracoabdominal nerves.

Blood supply

Lower intercostal, subcostal and deep circumflex iliac arteries.

Clinical relevance

Its aponeurotic lower edge — the inguinal ligament — frames the floor of the inguinal canal where hernias emerge; muscle strains here sideline tennis players and rowers.

Educational anatomy reference, not medical advice. About this content.