Infrahyoid muscles lie inferior ("infra") to the hyoid bone.
Because of their actions on the larynx and hyoid bone, the infrahyoid muscles are involved in swallowing and speech.
Originates on the manubrium of the sternum and the first costal cartilage and inserts on the oblique line of the thyroid cartilage; it depresses the larynx. It overlies the trachea.