NECK MUSCLES ACTIONS
Posterior Scalene
Unilateral contraction causes lateral flexion of the neck. Reversed muscle action causes Elevation of 2nd rib
Omohyoid
Depression of hyoid
Sternohyoid
Depression of hyoid
Thyrohyoid
Depression of hyoid and Elevation of thyroid cartilage
Sternothyroid
Depression of thyroid cartilage
Platysma
Draws up the skin of superior chest and neck, creating ridges in neck skin. Assists in drawing the lip laterally and depresses the mandible
Geniohyoid
Elevation of hyoid
Stylohyoid
Elevation of hyoid
Mylohyoid
Elevation of hyoid and depresses the mandible
Digastric
Elevation of hyoid, depression of the mandible, and retraction of the mandible.
Middle Scalene
Bilateral contraction: flexion of the neck. Unilateral contraction causes lateral flexion of the neck. Reversed muscle action causes Elevation of 1st rib
Sternocleidomastoid (SCM)
Bilateral contraction: flexion of the neck. Unilateral contraction results in Lateral flexion of neck/head and Contralateral rotation of neck/head
Longus Capitis
Bilateral contraction causes Flexion of head/neck. Unilateral contraction causes Lateral flexion of head/neck
Longus Colli
Bilateral contraction causes weak flexion of neck. Unilateral contraction causes lateral flexion and contralateral rotation of the neck.
Anterior Scalene
Bilateral contraction: flexion of the neck. Unilateral contraction causes lateral flexion and contralateral rotation of the neck. Reversed muscle action causes Elevation of 1st rib
Rectus Capitis Anterior
Flexion of head
Rectus Capitis Lateralis
Lateral flexion of head