Quick Facts
Origin: Sternal end of clavicle and posterior surface of manubrium of sternum.
Insertion: Inferior border of body of hyoid bone.
Action: Depresses hyoid bone.
Innervation: Ansa cervicalis (C1-C3), from anterior rami of cervical plexus.
Arterial Supply: Infrahyoid branch of superior thyroid artery.
Origin
The sternohyoid muscle originates from the sternal end of the clavicle, along the posterior sternoclavicular ligaments, and the posterior surface of the manubrium of the sternum.
Insertion
The sternohyoid muscle courses in a superomedial direction towards the midline and inserts into the inferior border of the body of hyoid bone.
Key Features & Anatomical Relations
Variation is common and the sternohyoid may be absent or have additional fibrous slips. In particular, a separate portion with a clavicular attachment may be present, where it is named cleidohyoid (Tubbs, Shoja and Loukas, 2016).
Actions
The sternohyoid muscle depresses the hyoid bone after it has been elevated (Standring, 2016). It also fixes the hyoid bone in place with it opposes the actions of muscles that elevate the bone.
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
