(anatomy) A large vertebrate skeletal muscle divided into an ascending, descending, and transverse portion, attaching the neck and central spine to the outer extremity of the scapula; it functions in scapular elevation, adduction, and depression.
In the management of spasmodic torticollis, Xeomin is usually injected into the sternocleidomastoid, levator scapulae, scalenus, splenius capitis, and/or the trapezius muscle(s