Situated beneath the skin on the side of the neck and withers. It is a flat, triangular muscle, divided by a tendon into two portions, and sometimes described as two muscles-the cervical and dorsal trapezius.
Origin. - In front from the superior border of the ligamentum nuchae, from which its fibres pass downwards and backwards. Behind from the superior spines of the dorsal vertebrae from the 3rd to the 10th, whence its fibres pass downward and forward.
Insertion. - Into the tubercle on the outside of the spine of the scapula.
Action. - The cervical or neck portion acting alone would pull the shoulder upwards and forwards. The dorsal or back division acting alone would draw it upwards and backwards.