Iliocostalis


The iliocostalis is the muscle immediately lateral to the longissimus that is the nearest to the furrow that separates the epaxial muscles from the hypaxial. It lies very deep to the fleshy portion of the serratus posterior muscle.

Iliocostalis cervicis

The iliocostalis cervicis arises from the angles of the third, fourth, fifth, and sixth ribs, and is inserted into the posterior tubercles of the transverse processes of the fourth, fifth, and sixth cervical vertebrae.

Iliocostalis dorsi

The iliocostalis dorsi arises by flattened tendons from the upper borders of the angles of the lower six ribs medial to the tendons of insertion of the iliocostalis lumborum; these become muscular, and are inserted into the upper borders of the angles of the upper six ribs and into the back of the transverse process of the seventh cervical vertebra.

Iliocostalis lumborum

The iliocostalis lumborum is inserted, by six or seven flattened tendons, into the inferior borders of the angles of the lower six or seven ribs.