Iliocostalis muscle has a common origin from the
iliac crest, the
sacrum, the
thoracolumbar fascia, and the
spinous processes of the
vertebrae from
T11 to
L5.
Iliocostalis cervicis (cervicalis ascendens) 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 thoracis (musculus accessorius; iliocostalis thoracis) 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 (iliocostalis muscle; sacrolumbalis muscle) is inserted, by flattened
tendons, into the inferior borders of the angles of the lower six to nine
ribs.
Nerve supply Iliocostalis muscle is supplied by the
dorsal rami of
spinal nerves. == Function ==