Agonist and antagonist muscle pairs The muscle allows the head and vertebrae to extend. El Paso, TX The assessment and treatment of the sternocleidomastoid is closely related to that of the scalenes. extensor indicis synergist and antagonistpolitical candidate websites. Sternocleidomastoid muscle - Wikipedia Muscle synergists We describe muscles that work together to create a movement as synergists. Identify the skeletal muscles and The sternocleidomastoid muscle flexes the neck and helps with movement of the head. Extensor Digitorum. Sternocleidomastoid Muscle: Anatomy and Function The postvertebral muscles are responsible for your posture and movement of the spine. Upper trapezius, lower serratus anterior: … Wiki User. connects base of skull to vertebrae of neck/thorax. This question focuses on Learning Objective 4: … FEEDBACK This question focuses on Learning Objective 3: Identify muscles of the head and neck, torso, upper body, and lower body. - Superficialis - Major - Teres - Profundus - Superficialis. Sternocleidomastoid