what is the function, location, and innervation of the Trapezius muscle?
function: superior fibers: elevates and superiorly rotate scapula; middle fibers: retract scapula; inferior fibers: depress scapula
origin: occipital bone (superior nuchal line); ligamentum nuchae; spinous processes of C7-T12
insertion: clavical; acromion process and spine of scapula
innervation: accessory nerve (CN XI)