intrinsic back muscles

Question 1

what is the proximal attachment of the splenius muscles?

Answer 1

proximal: nuchal ligament and spinous processes of C7-T6.

Question 2

what is the distal attachment of splenius capitis?

Answer 2

distal: mastoid process of temporal bone and lateral third of superior nuchal line of occipital bone.

Question 3

what is the distal attachment of splenius cervicis?

Answer 3

distal: tubercles of transverse processes of C1-3 or 4.

Question 4

what is the action of the erector spinae group?

Answer 4

bilaterally extend vertebral column and head; as back is flexed controls movement via eccentric contraction; unilaterally they laterally flex vertebral column.

Question 5

what is the proximal attachment of the erector spinae group? what nerve innervates these muscles?

Answer 5

proximal: broad tendon from posterior part of iliac crest, posterior surface of sacrum.
innervation: posterior rami of spinal nerves.

Question 6

what is the distal attachment of iliocostalis?

Answer 6

distal: lumborum, Thoracis and cervicis.

Question 7

what is the distal attachment of longissimus?

Answer 7

distal: Thoracis, cervicis, capitis and mastoid process of temporal bone.

Question 8

what is the distal attachment of spinalis?

Answer 8

distal: Thoracis, cervicis and capitis.

Question 9

what is the action of splenius? what nerve innervates it?

Answer 9

action: laterally flex neck and rotate head to side of active muscles, extend head and neck.
innervation: posterior rami of spinal nerve.