The Probert Encyclopaedia of Medicine

TRAPEZIUS

The trapezius is one of the largest shoulder muscles and the most superficial muscle on the back of the neck and upper trunk. It is a broad, flat triangular muscle that lies just below the skin. The muscle originates from the superior nuchal line, the external occipital protuberance, the ligamentum nuchae, and the spinous processes of the seventh cervical and the thoracic vertebrae. It covers the upper back part of the neck and shoulders and inserts in the clavicle, acromion, and upper border of the spine of the scapula. The trapezius is innervated by the accessory nerve (motor) and the cervical plexus (sensory) and is supplied by the cervical artery. This muscle links the neck with the dorsal vertebrae, ribs, and scapula. It is used to turn and tilt the head, raise and twist the arms, and to shrug or steady the shoulders. The trapezius is a postural muscle as well as an active mover.
Research Trapezius