The trapezius muscle is a large diamond shaped muscle that travels from the neck to the mid back. It originates on the nuchal ligament, and the spinous processes of C6-T12. It has its insertion on the scapular spine, acromion process, and distal clavicle. The upper fibres of this muscle work to elevate the shoulder, and rotate the glenoid fossa upwards. The lower fibres assist this motion, and the middle fibres are strong adductors of the scapula. This is the number one muscle in the body tp get trigger points. Trigger points in the lateral upper edge refer pain in the lateral neck and temples, a common cause of headaches. Points in the middle and lower fibres refer pain into the posterior neck and shoulder.