Where is the trapezius muscle located and what is its primary function?
In human anatomy, the trapezius is a large superficial muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula (shoulder blade). The trapezius has three functional regions: The superior region (descending part), which supports the weight of the upper limb, the intermediate region (transverse part), which retracts the scapulae, and the inferior region (ascending part), which medially rotates and depresses the scapulae. It is innervated by the accessory nerve (Cranial Nerve 11) and the ventral rami of third (C3) and fourth (C4) cervical spinal nerves, which also supplies the sternocleidomastoid muscle. The two trapezius muscles together resemble a trapezium (trapezoid in American English), or diamond-shaped quadrilateral; the four points of the diamond are: the head (at the occipital protuberance), the two shoulders, and the middle of the back (at the spinous process of the twelfth thoracic vertebra, T12). Trape
Three Areas of the Trapezius Muscle: The trapezius muscle is divided into 3 areas: * upper fibers * middle fibers * lower fibers. The significance of this division lies in the variety of functions performed by this muscle. Functions of the Trapezius Muscle: The trapezius muscle has several functions: * to move the shoulder blade in toward the spine * to rotate the shoulder blade so that the topmost part of the upper arm faces up * to move the shoulder blade up and down * to bring the head and neck in a backward direction * to rotate and side bend the neck * to assist in breathing The Effects of the Trapezius Muscle on the Neck: Because the trapezius muscle works to move the neck in several directions, its degree of tightness or looseness affects neck flexibility. For people who work at desks and computers, or who spend many hours driving, the upper trapezius is the muscle on top of your shoulder that becomes very sore and painful. The Trapezius Muscle as a Breathing Muscle: The trapezi
