Rotatores insert on the base of spinous processes how many levels above the origin?

Rotatores insert on the base of spinous processes how many levels above the origin?

• A. Spinous processes of C2-C5
• B. Transverse processes
• C. Spinous processes at the same level
• D. 1-2 levels above the origin

Answer: (D)

Rotatores are short intrinsic back muscles that run from the transverse process of one vertebra upward and medially to insert on the base of the spinous process of a higher vertebra. Because their fibers extend one or two levels, they insert 1–2 levels above their origin. This includes both the short rotatores (brevis) which insert one level above and the longer rotatores (longus) which insert two levels above. They’re innervated by the dorsal rami and function to stabilize the spine and aid rotation.

Rotatores are short intrinsic back muscles that run from the transverse process of one vertebra upward and medially to insert on the base of the spinous process of a higher vertebra. Because their fibers extend one or two levels, they insert 1–2 levels above their origin. This includes both the short rotatores (brevis) which insert one level above and the longer rotatores (longus) which insert two levels above. They’re innervated by the dorsal rami and function to stabilize the spine and aid rotation.