Neck Muscle

Question 1

What is the P of the Sternocleidomastoid?

Answer 1

Watching an athletic event, socializing, or driving

Question 2

What is the MA of the Sternocleidomastoid?

Answer 2

Bilateral: extension of neck at atlanto-occipital joints, flexion of cervical vertebra so that chin approaches manubrium, and extension of the superior cervical vertebrae while flexing inferior vertebrae so chin is thrust forward with head kept level

Unilateral: lateral flexion of the neck and rotation so face is turned superiorly toward other side (contralateral rotation)

With cervical vertebrae fixed, elevation of manubrium and medial ends of clavicle, assisting pump-handle action of deep respiration

Question 3

What is the SMA of the Sternocleidomastoid?

Answer 3

Mastoid process and superior nuchal line

Question 4

What is the ILA of the Sternocleidomastoid?

Answer 4

Sternal Head: manubrium of sternum

Clavicular Head: medial 1/3 of clavicle

Question 5

What is the N for the Sternocleidomastoid?

Answer 5

Spinal accessory nerve (CN XI) (motor) and ventral ramus of C3 and C4 (pain and proprioception)