Internal Oblique - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The internal oblique is a muscle of the anterior abdominal wall. It is a broad, sheet-like muscle, located deep to the external oblique. Attachments: Originates from the inguinal ligament, iliac crest and lumbodorsal fascia. It inserts onto ribs 10-12. Actions: Bilateral contraction compresses the abdomen, while unilateral contraction ipsilaterally rotates the torso. Innervation: Thoracoabdominal nerves (T7-T11), subcostal nerve (T12) and branches of the lumbar plexus. Blood supply: Lower posterior intercostal and subcostal arteries, superior and inferior epigastric arteries, superficial and deep circumflex arteries, posterior lumbar arteries. By TeachMeSeries Ltd (2026) Fig 1Lateral view of the abdominal wall. The internal oblique is visible – note that its fibres are perpendicular to those of the external oblique. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Pro Feature - Dissection Atlas Dissection of the anterolateral abdominal wall Dissection of the anterolateral abdominal wall You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Frequent questions What is the internal oblique muscle? The internal oblique is a broad muscle located in the anterior abdominal wall, situated beneath the external oblique. It plays a crucial role in abdominal compression and torso rotation. What are the attachments of the internal oblique? The internal oblique originates from the inguinal ligament, iliac crest, and lumbodorsal fascia, and it inserts onto the lower ribs, specifically ribs 10 to 12. These attachments allow it to facilitate movements of the torso. What actions does the internal oblique perform? The internal oblique muscle compresses the abdomen when both sides contract simultaneously and enables ipsilateral rotation of the torso during unilateral contraction. This dual functionality is essential for various movements and stability. What is the innervation of the internal oblique? The internal oblique is innervated by the thoracoabdominal nerves (T7-T11), the subcostal nerve (T12), and branches from the lumbar plexus. This nerve supply is vital for muscle contraction and coordination. What is the blood supply to the internal oblique? The internal oblique receives blood from several arteries, including the lower posterior intercostal and subcostal arteries, as well as the superior and inferior epigastric arteries. Additionally, it is supplied by the superficial and deep circumflex arteries and the posterior lumbar arteries. Rate This Article