Iliac rib muscle


Latin: Iliocostalis muscle
English: iliocostal muscle

Synergists: Muscle latissimus dorsi
Antagonists: Sternocleidomastoideus muscle, longus colli muscle, longus capitis


The iliocostalis muscle (iliac-rib muscle) is a muscle that belongs to the autochthonous back muscles.
It is located above the transverse processes (epaxial) and to the side of the longissimus muscle.
It is located in the lateral tract of the M. erector spinae and there it belongs to the sacrospinal system.

There is a lumbar, chest and neck section:

  • Loin part (Iliocostalis lumborum muscle) originates from the iliac and sacrum (Sacrum) and extends to the costal processes (Costal process) of the upper lumbar vertebrae and the 6th – 9th Rib.
  • Chest part (Iliocostalis thoracis muscle) arises on the lower ribs and ends on the upper ribs
  • Neck part (Iliocostalis cervicis muscle) originates from the 6. – 3. Rib and attaches to the transverse processes of the 6th – 4th Cervical vertebra, in domestic animals only on the 7th cervical vertebra.


Approach: Ribs and cervical vertebrae

Origin: Iliac and sacrum

Innervation: Spinal nerves (rami dorsales)


The iliocostalis muscle serves like the rest epaxial muscles, as a stabilizer of the spine. It also erects the spine, which is why it is also known as the "erector spinae muscle" ("erector of the spine") together with the epaxial muscles.

With unilateral contraction of the paired muscle, the spine is bent to one side.