Main Model
14 Trapezius muscle
Trapezius
Proximal Attachment: Medial third of superior nuchal line; external occipital protuberance; nuchal ligament; spinous processes of C7-T12 vertebrae
Distal Attachment: Lateral third of clavicle; acromion and spine of scapula
Innervation: Spinal accessory nerve (CN XI) (motor fibers) and C3, C4 spinal nerves (pain and proprioceptive fibers)
Main Action(s): Descending part elevates; ascending part depresses; and middle part (or all parts together) retracts scapula; descending and ascending parts act together to rotate glenoid cavity superiorly