The infrahyoid muscles are a group of four muscles located in the neck, below the hyoid bone. These muscles include the sternohyoid, omohyoid, sternothyroid, and thyrohyoid. They play a crucial role in stabilizing and moving the hyoid bone and larynx during swallowing and speaking. These muscles are innervated primarily by the ansa cervicalis, a loop of nerves in the neck. The infrahyoid muscles help lower the hyoid bone and larynx, facilitating the process of swallowing and contributing to the proper function of the voice box.