The eleventh thoracic dorsal spinal rami run posteriorly, adjacent to the zygapophyseal joints between T11 and T12 and divide into medial and lateral branches.

The medial branches emerge between the joints and the medial edges of the superior costotransverse ligaments and the intertransversarii muscles, to pass between semispinalis thoracis and multifidus to reach the spinous processes of T11 and T12.  Here they pierce the trapezius muscle to terminate in the overlying skin.  The lateral branches emerge between the superior costotransverse ligaments and the intertransversarii muscles and pass between the longissimus thoracis and iliocostalis cervicis muscles to reach the medial border of levatores costarum.

Supply
The eleventh thoracic dorsal spinal rami supply the multifidus, longissimus thoracis, iliocostalis cervicis, levatores costarum and interspinales muscles as well as the skin overlying the eleventh and twelfth thoracic spinous processes.