The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles.
The primary movements of the muscle rotate in the opposite direction of the head and bend the neck. The sternocleidomastoid is innervated by the accessory nerve.
It is named sternocleidomastoid because it originates in the manubrium of the sternum and clavicle, and is an insertion into the mastoid process of the temporal bone of the skull.
The sternocleidomastoid muscle arises from two places:
The sternum and the clavicular’s manubrium. It travels diagonally across the edge of the neck and is involved in the mastoid process of the temporal bone of the skull. The sternocleidomastoid is thick and narrow in its center, and broad and thin at both ends.
The sternum is a round fascia, the front is soft, the back is fleshy, arising from the front of the front of the manubrium sterni. It travels better, later, and later.
The clavicular head is composed of fleshy and aponeurotic fibers, arising from the upper, frontal surface of the medial third of the clavicle; It is directed almost directly upwards.
The two heads are separated from each other by a triangular interval (supraclavicular fossa), but gradually mix, down the middle of the neck, into a thick, round muscle that is inserted into the lateral surface, by a strong tendon. is. The mastoid process, from its apex to its superior border, and by a thin aponeurosis in the lateral half of the superior duct line of the occipital bone.