ANATOMY

Omohyoid Muscle is situated at the front of Neck and has two bellies that are separated by an Intermediate Tendon. It originates from the upper border of the Scapula and Superior Transverse Scapular Ligament (converts scapular notch into an opening) crossing the Scapular Notch (notch in the superior border of Scapula). The two bellies of the muscle are as follows.

• Inferior Belly

• Superior Belly

Inferior belly is the point of origin for Omohyoid Muscle. It forms a flat narrow Fasciculus (skeletal muscle fibers, connective tissue) that is inclined forward and upward at the lower part of Neck. It then passes Sternocleidomastoid Muscle and forms an obtuse angle after becoming Tendinous.

The Omohyoid Muscle ends in the Superior Belly passing upward close to lateral side of Sternohyoid. There it inserts in the lower side of Hyoid Bone.

Process of Deep Cervical Fascia held the central tendon of Omohyoid Muscle in place. It is covered in a sheath and is attached to the Clavicle and First Rib.

INNERVATION

Omohyoid Muscle is innervated by the following nerves.

• Ventral Ramus of Ansa Cervicalis C1 to Superior Belly of the muscle

• Ventral Ramus of Ansa Cervicalis C2 and C3 to Inferior Belly of the muscle

BLOOD SUPPLY

Following arteries supply nutrients and blood to Omohyoid Muscle.

• Infrahyoid Artery from Superior Thyroid Artery

• Suprahyoid branch of Lingual Artery

• Superficial Artery branch of Subclavian Artery

• Inferior Thyroid Artery from Subclavian Artery

FUNCTION

Omohyoid Muscle’s main function is to depress the elevated Hyoid Bone and hence Larynx. It also helps in raising Cervical Fascia.

CLINICAL SIGNIFICANCE

Conditions that affect the Omohyoid Muscles are as follows.

• Injury due to overuse

• Tears

• Strain

• Contusions

• Myopathy (inherited or acquired disease of muscle)

• Atrophy

• Infectious myositis

Above conditions can result into following symptoms.

• Throat pain

• Difficulty in swallowing

• Difficulty in talking

• Fever

• Swelling

• Muscle spasm