On each side of the spinal column, the levator costae are a set of twelve fan-shaped muscles which originate from the tips of the transverse processes of C7 to T11. Each muscle passes inferolaterally for a short distance to insert into the posterosuperior surface of the rib that lies inferiorly, near to its angle.
The action of the group is to elevate the ribs.
Although often considered as thoracic muscles, their developmental origin is with the muscles of the back. This is reflected in their innervation: the posterior rami of spinal nerves C8 to T11.