Iliocostalis thoracis
Back
Deep muscle — it lies under other muscles. X-ray makes the muscles over it see-through.
- Origin
- Angles of the lower six ribs
- Insertion
- Angles of the upper six ribs and the transverse process of C7
- Action
- Extends and laterally flexes the spine; keeps the thoracic spine upright
- Nerve supply
- Dorsal rami of the spinal nerves
The middle section of the iliocostalis, linking the lower ribs to the upper ribs along the outer edge of the erector spinae.