- See: torticollis:
- origin: sternal head: anterior surface of the manubrium; clavicular head: superior surface of the medial half of clavicle;
- insertion:
- lateral surface of the mastoid process of the temporal bone and lateral half of the superior nuchal line of the occipital;
- action:
- acting unilaterally, draws the head toward the ipsilateral shoulder and rotates head to the opposite side; acting bilaterally, flexes the head;
- nerve supply:
- anterior rami of C2, C3; Spinal portion of the accessory nerve;
- synergist: scalene group;
Long-term results of open sternocleidomastoid tenotomy for idiopathic muscular torticollis.