Layer 4 Back Muscles

Question 1

Which muscles are in the 4th layer of the back?

Answer 1

Splenius capitis and cervicis

Question 2

What is the origin of splenius capitis?

Answer 2

Lower 1/2 nuchal L, spinous processes of C7-T3/4

Question 3

What is the insertion of splenius capitis?

Answer 3

Mastoid process of temporal bone, lateral 1/3 superior nuchal line of the occipital bone

Question 4

What is the action of splenius capitis and cervicis muscles?

Answer 4

Extend neck when working bilaterally; laterally flex the neck and rotate face toward when working unilaterally

Question 5

What are the splenius capitis and cervicis muscles innervated by?

Answer 5

Posterior rami

Question 6

What is the origin of splenius cervicis?

Answer 6

Spinous processes T3-6

Question 7

What is the insertion for splenius cervicis?

Answer 7

Transverse processes C1-3/4

Question 8

What is a back sprain?

Answer 8

An injury to the ligamentous attachments between bone, usually the results of inadequate stretching before activity

Question 9

What is a back strain?

Answer 9

Involves excessive stretching and sometimes tearing of muscle fibers produced by an overly strong muscular contraction

Question 10

What is a protective measure of the back in response to injury and inflammation?

Answer 10

Spasm of the muscle tissue or involuntary contraction