abdominal external oblique muscle

The abdominal external oblique muscle (abdominal external oblique muscle) is the outermost of the three flat muscles of the lateral abdominal wall. It is the most superficial of the lateral muscles, lying immediately above the internal oblique muscle.

The abdominal external oblique muscle is located on the lateral and anterior abdominal wall. Its fibers run obliquely downward and medially, originating from the lower ribs and inserting into the iliac crest, inguinal ligament, and the linea alba.

The external oblique flexes the trunk forward, assists with lateral flexion and rotation of the trunk, and compresses the abdominal contents. It also helps with forced exhalation and contributes to trunk stability during movement.

The external oblique can be strained during twisting or heavy lifting activities. Oblique hernias can develop at weak points near the inguinal region where this muscle's aponeurosis forms part of the inguinal canal. Core weakness can reduce the effectiveness of this muscle.

The external oblique is the most superficial of the two muscles and its fibers run downward and medially, whereas the internal oblique lies deep to it with fibers running at roughly right angles (upward and medially). Together they provide multidirectional trunk stabilization.