O & I: Intermediate and Deep Back Muscles

Question 1

Origin: Splenius

Answer 1

Capitis: Nuchal ligament and spinous processes of C7 - T4 vertebrae

Cervicis: Spinous processes of T3-T6

Question 2

Insertion: Splenius

Answer 2

Capitis: mastoid process of the temporal bone and lateral third of superior nuchal line of occipital bone

Cervicis: tubercles of transverse processes of C1-C3 or C4 vertebrae

Question 3

Innervation: Splenius

Answer 3

Posterior rami of middle cervical nerves

Question 4

Actions: Splenius

Answer 4

Acting Unilaterally: laterally flex the neck and rotate the head to side of active muscle

Acting Bilaterally: extend the head and neck

Question 5

Origin: Erector Spinae

Answer 5

Arises by a broad tendon from the posterior part of the iliac crest, posterior surface of the sacrum, sacro-iliac ligaments, sacral and inferior lumbar spinous processes, and supraspinous ligament

Question 6

Insertion: Erector Spinae

Answer 6

Iliocostalis: (3 parts lumborum, thoracic, cervicis) fibers run superiorly to angles of lower ribs and cervical transverse process

Longissimus: (3 parts thoracic, cervicis, capitis) fibers run superiorly to ribs between tubercles and angles to transverse process in thoracic and cervical regions and to mastoid process of temporal bone

Spinalis: (3 parts thoracic, cervicis, capitis) fibers run superiorly to spinous process in upper thoracic region and to cranium

Question 7

Innervation: Erector Spinae

Answer 7

Posterior rami of lower cervical nerves

Question 8

Action: Erector Spinae

Answer 8

Acting Bilaterally: extend vertebral column and head; as back is flexed, control movement via eccentric contraction

Acting unilaterally: laterally flex vertebral column

Question 9

Origin: Multifidus

Answer 9

arises from posterior sacrum, posterior superior iliac spine of the ilium, aponeurosis of erector spinae, sacra-iliac ligaments, mammillary processes of lumbar vertebrae, transverse processes of T1-T3, articular processes of C4-C7

Question 10

Insertion: Multifidus

Answer 10

thickest in lumbar region; fibers pass obliquely superomedially to entire length of spinous processes, located 2-4 segments superior to proximal attachment

Question 11

Innervation: Multifidus

Answer 11

Posterior rami of spinal nerves

Question 12

Action: Multifidus

Answer 12

stabilizes vertebrae during local movements of vertebral column

Question 13

Origin: Serratus Posterior Superior

Answer 13

Nuchal ligament and Spinous process of C7-T3

Question 14

Insertion: Serratus Posterior Superior

Answer 14

Superior borders of ribs 2-5, lateral to their angles

Question 15

Innervation: Serratus Posterior Superior

Answer 15

Anterior rami T2-T5

Question 16

Action: Serratus Posterior Superior

Answer 16

elevates ribs 2-5

Question 17

Origin: Serratus Posterior Inferior

Answer 17

spinous process of T11-L2

Question 18

Insertion: Serratus Posterior Inferior

Answer 18

Inferior border of ribs 9-12, lateral to their angles

Question 19

Innervation: Serratus Posterior Inferior

Answer 19

anterior rami T9-T12

Question 20

Action: Serratus Posterior Inferior

Answer 20

depresses ribs 9-12

Question 21

Origin: Semispinalis capitis

Answer 21

transverse process of C7-T6 and the articular process of C4-C6

Question 22

Insertion: Semispinalis capitis

Answer 22

Between the superior and inferior nuchal lines of the occipital bone medially

Question 23

Innervation: Semispinalis capitis

Answer 23

Posterior rami of spinal nerves

Question 24

Action: Semispinalis capitis

Answer 24

Unilaterally — extends and laterally rotates head to opposite side

Bilaterally — extends head

Question 25

Origin: Semispinalis Cervicis

Answer 25

Transverse process of T1-T5

Question 26

Insertion: Semispinalis Cervicis

Answer 26

spinous process of C2-C5

Question 27

Innervation: Semispinalis Cervicis

Answer 27

posterior rami of spinal nerves

Question 28

Action: Semispinalis Cervicis

Answer 28

Unilaterally — extends and laterally rotates head to opposite side

Bilaterally — extends head

Question 29

Origin: Rotatores

Answer 29

Arise from transverse processes of vertebrae; best developed in thoracic region

Question 30

Insertion: Rotatores

Answer 30

Fibers run superomedially attaching to spinous process of vertebra immediately (brevis) or 2 segments (longus) superior to vertebra attachment.

Question 31

Innervation: Rotatores

Answer 31

Posterior rami of spinal nerves

Question 32

Action: Rotatores

Answer 32

Stabilize vertebrae and assist /c local extension and rotators movements of vertebral column; may function as organs of proprioception