Myology of the Neck

Question 1

Sternocleidomastoid

Answer 1

O- Sternal head: Anterior manubrium of the sternum.
Clavicular head: Medial third of the clavicle.
I- Mastoid process and the lateral, superior nuchal line
N- Spinal accessory nerve (C2, C3)
A- Unilaterally: Lateral flex head and neck to same side and rotate to opposite side.
Bilaterally: Flex neck, assists to elevate ribs during inhalation.

Question 2

Anterior Scalene

Answer 2

O- Transverse processes of Cervical 4-6 (anterior tubercles)
I- First rib
N- Cervical spinal nerves (C4-C6)
A- Unilaterally: Lateral flex head and neck to same side, rotate head and neck to opposite side
Bilaterally: Elevate ribs, flex head and neck

Question 3

Middle Scalene

Answer 3

O- Transverse processes of Cervical 6 and 7.
I- Second rib
N- Cervical spinal nerve (C4-C6)
A- Unilaterally: Lateral flex head and neck to same side, rotate head and neck to opposite side
Bilaterally: Elevate ribs, flex head and neck

Question 4

Posterior Scalene

Answer 4

O- Transverse processes of Cervical 6 and 7.
I- Second rib.
N- Cervical spinal nerve (C4-C6)
A- Unilaterally: Lateral flex head and neck to same side, rotate head and neck to opposite side
Bilaterally: Elevate ribs, flex head and neck

Question 5

Levator Scapulae

Answer 5

O- Transverse processes of Cervical 1-4
I- Medial border of scapula between superior angle and the spine of scapula.
N- Cervical nerve C3+C4 and Dorsal scapula nerve C4+C5.
A- Unilaterally: Elevate scapula, downwardly rotate scapula, lateral flex head and neck, rotate same side.
Bilaterally: Extend head and neck.

Question 6

Trapezius

Answer 6

3 groups: upper, middle and lower fiber.
O- External occiput protuberance, medial, superior nuchal line on occiput, ligamentum nuchae and the spinous processes of C7- T12
I- Lateral 1/3 of clavicle, acromion and spine of scapula.
N- Cranial Nerve and ventral rami C2-C4.
A- Upper fibers: Bilaterally: Extend head and neck Unilaterally: Laterally flex head and neck to same side, rotate head and neck to opposite side, elevate and upwardly rotate scapula.
Middle fibers: Abduct and stabilize scapula
Lower fibers: Depress scapula, upwardly rotate scapula.