- Anatomy:
- origin:
- from bondies of the 5th, 6th, and 7th cervical and the 1st, 2nd and 3rd thoracic vertebrae,
with the slips from transverse processes;
- insertion:
- it lies on the anterior surface of the vertebral bodies between C1 and T3;
- bodies of 2nd, 3rd, and 4th cervicals with slips to transverse processes;
- action:
- acting bilaterally, flexes cervical vertebrae; acting unilaterally, assists in rotation and lateral flexion;
- synergists:
- scalenus group, sterncleidomastoid,
longus capitis, suprahyoid, infrahyoid and the platysma;
