Rotatores

  • The rotatores (or rotatores spinae muscles, Latin: musculi rotatores) are deep muscles of the back located laterally along the spine. Each muscle extends between the transverse and spinous processes of the vertebrae. The main functions of the rotatores include stabilizing, rotating, and extending the spine. 

    There are eleven rotatores on each side of the vertebral column. These muscles are present in all regions of the spine, but the thoracic rotatores are the most developed. They can be subdivided into long rotatores and short rotatores based on the length of their muscle fibers.

    Origin

    The rotatores muscles originate from the transverse processes of vertebrae.

    Insertion

    The muscle fibers of the rotatores insert into the junctions of transverse processes and laminae, extending to the spinous processes of the vertebrae. The short rotatores attach to the vertebrae one level above their origin, while the long rotatores insert - two levels above.

    Action

    The main actions provided by the rotatores include extending the spine when contracting on both sides, and rotating the thoracic spine contralaterally when contracting on one side. These muscles also serve as proprioceptive transducers that monitor the position and movements of the vertebral column.

    Innervation

    The rotatores are innervated by the medial branches of the dorsal rami of spinal nerves.

    Blood supply

    These muscles are supplied mainly by the dorsal branches of the posterior intercostal arteries and the lumbar arteries.