Omohyoid Muscle

Description

Curving across the lower lateral neck, the omohyoid is traced from its inferior belly arising on the superior border of the scapula near the suprascapular notch, then running anterosuperiorly toward an intermediate tendon. That tendon lies deep to the sternocleidomastoid and is tethered by a fascial sling to the clavicle, after which the superior belly continues medially to the body of the hyoid bone. Posteriorly, cervical vertebrae form the axial backdrop, while the scapula, lateral clavicle, and adjacent ribs frame the shoulder girdle; nearby fibers of trapezius and sternocleidomastoid set the posterior and anterior boundaries of the posterior triangle. Topography here matters. The inferior belly of omohyoid crosses the posterior triangle and can overlie the lower portion of the brachial plexus and the transverse cervical and suprascapular vessels, relationships that become relevant in level IV and V neck dissection and during exploration for thoracic outlet related symptoms. Medially, the muscle and its fascial sling sit close to the internal jugular vein and the carotid sheath, so this view supports teaching of safe planes for central venous access and for identifying the ansa cervicalis branches that innervate the infrahyoid strap muscles. Small muscle. Big landmark. Use this illustration in head and neck anatomy courses to anchor the infrahyoid strap muscle layout, in surgical education materials covering cervical lymph node levels and exposure of the carotid sheath, or in clinical reference content discussing ultrasound-guided internal jugular cannulation and omohyoid-related neck pain syndromes. Anatomical accuracy verified by SciePro's Medical Advisory Board.