In the cervical region they are best developed, consisting of rounded muscular and tendinous fasciculi, and are placed in pairs, passing between the anterior and the posterior tubercles respectively of the transverse processes of two contiguous vertebrae, and separated from one another by an anterior primary division of the cervical nerve, which lies in the groove between them.

These are called the thoracic intertransversarii and are supplied by the posterior rami of the spinal nerves.

In the lumbar region they are arranged in pairs, on either side of the vertebral column, The intertransversarii laterales are supplied by the anterior rami, and the intertransversarii mediales by the posterior rami of the spinal nerves.

They contribute little to no movement on their own, but they stabilize adjoining vertebrae allowing more effective action from other muscle groups.

This article incorporates text in the public domain from page 401 of the 20th edition of Gray's Anatomy (1918)