Back Muscles – Origin, Insertion, Action & Innervation Practice Test

Knowing where a muscle begins helps you distinguish muscles that move the same region. The rhomboid group retracts the scapula and downwardly rotates it. Rhomboid minor originates from the spinous processes of C7 and T1 (and the nearby lower part of the ligamentum nuchae) and inserts on the medial border of the scapula, above the scapular spine. Rhomboid major, by contrast, starts from T2–T5; levator scapulae starts from the transverse processes of C1–C4; and trapezius has a broader set of origins from the occipital region and down to T12. So the muscle with origins at C7–T1 is rhomboid minor. (Innervation for both rhomboids is the dorsal scapular nerve, C4–C5.)