GLOSSARY

The trapezius is a large, superficial, diamond-shaped muscle in the upper back and neck; the right and left muscles together form a trapezoid, moving and stabilising the scapula.

Attachments and Innervation

• Origin: the occipital bone, the nuchal ligament, and the spinous processes of C7–T12.
• Insertion: the lateral third of the clavicle, the acromion, and the spine of the scapula.
• Nerve: the spinal accessory nerve (CN XI), with proprioception from C3 and C4.

Actions of the Three Parts