Origin
External surfaces of the fifth to twelfth ribs
Insertion
Linea alba, iliac crest, pubic crest & pubic tubercle
Actions
- Lateral flexion of the trunk (unilateral contraction)
- Rotation of the trunk (unilateral contraction)
- Flexion of the trunk (bilateral contraction)
- Assistive in forced expiration
Innervation
- Intercostal nerves (T8-T11)
- Subcostal nerve (T12)
Blood Supply
- Lower posterior intercostal artery
- Subcostal artery
- Deep circumflex iliac artery
- Superior and inferior epigastric arteries
Would you like to learn more about the external oblique muscle? Then check out the external oblique muscle article and video by clicking the link below: External Oblique Muscle Anatomy
