External oblique (left) (Musculus obliquus externus abdominis)
Educational content only — not medical advice.
Anatomy
The broadest and most superficial of the four abdominal muscles; its fibres run forward and downward like hands-in-pockets. It bends and rotates the trunk and compresses the viscera in coughing, childbirth and defecation.
Origin & insertion
Origin: external surfaces of ribs 5–12. Insertion: linea alba, iliac crest and (via its lower free border) the inguinal ligament.
Action
Bends the trunk sideways and rotates it to the opposite side; compresses the abdomen.
Innervation
Lower intercostal nerves (T7–T12)
Clinical notes
An inguinal hernia protrudes above the inguinal ligament formed by its lower border — the most common hernia type, far more frequent in men.
Related structures
Educational references
FAQ
What is the role of the External oblique (left)?
The broadest and most superficial of the four abdominal muscles; its fibres run forward and downward like hands-in-pockets. It bends and rotates the trunk and compresses the viscera in coughing, childbirth and defecation.
Why is the External oblique (left) clinically important?
An inguinal hernia protrudes above the inguinal ligament formed by its lower border — the most common hernia type, far more frequent in men.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details