Omohyoid Inferior Belly

venter inferior m. omohyoidei

The inferior belly runs from the scapula to the intermediate tendon, crossing the posterior triangle. The right angle between the superior and inferior bellies forms the anatomical landmark dividing the carotid triangle from the muscular triangle.

Nerve: Ansa cervicalis (C1, C2, C3) Blood Supply: Transverse cervical artery Region: Neck

Anatomical Data

Origin, Insertion & Supply

Origin	Superior border of the scapula — near the suprascapular notch
Insertion	Intermediate tendon — anchored by the deep cervical fascia to the clavicle
Nerve Supply	Ansa cervicalis (C1, C2, C3)
Blood Supply	Transverse cervical artery

Biomechanics

Function & Actions

Actions	Depresses the hyoid; Tenses the posterior cervical fascia

Clinical Relevance

Clinical Notes

The inferior omohyoid belly is the boundary between the posterior triangle and the supraclavicular triangle. In selective neck dissection, it forms the inferior boundary of level III and the superior boundary of level IV nodal territory.

Palpation

Visible as a diagonal cord in the posterior lateral neck during neck extension.

Pathology

Common Injuries & Conditions

Inferior Omohyoid Belly as Neck Level Landmark

The inferior belly serves as the anatomical boundary between neck nodal levels III and IV in selective neck dissection planning.