Intrinsic Back Musculature

Question 1

Intrinsic back muscles:

Superficial (2):

Intermediate (3):

Deep (3):

Answer 1

Superficial: Splenius capitis, splenius cervicis

Intermediate: Spinalis, Longissimus, Iliocostalis

Deep: Semispinalis, multifidus, Rotatores

Question 2

Identify this muscle

Answer 2

splenius capitus

Question 3

Identify this muscle

Answer 3

splenius cervicis

Question 4

Splenius Capitis
Origin:
insertion:
action:
innervation:

Answer 4

Origin: Nuchal ligament and spinous processes of C7-T3/T4

Insertion: Mastoid process of the temporal bone and nuchal line

Action:
o Bilateral: Extends the head and neck
o Unilateral: Rotates and laterally flexes the head to the same side

Innervation: Posterior rami of cervical spinal nerves

Question 5

Splenius cervicis and capitis action:

Answer 5

• Unilaterally – laterally flex the neck and rotate head to the side of the active muscle
• Bilaterally – Extend head and neck

Question 6

Splenius cervicis and capitis innervation

Answer 6

Posterior rami of spinal nerves
Superficial intrinsic
back muscles

Question 7

Spinalis

Origin:
Insertion:
Action:
Innervation:

Answer 7

Origin: broad tendon from posterior Iliac crest; sacral and inf. Lumbar spinous processes, and supraspinous ligament

Insertion: Spinous processes of thoracic + cervical vertebrae

Action:
o Bilateral: Extends the vertebral column + head
o Unilateral: Laterally flexes the spine to the same side

Innervation: Posterior rami of spinal nerves

Question 8

Identify this muscle

Answer 8

spinalis

Question 9

Longissimus

Origin:
Insertion:
Action:
Innervation:

Answer 9

Origin: broad tendon from posterior Iliac crest; sacral and inf. Lumbar spinous processes, and supraspinous ligament

Insertion: Transverse processes of (posterio-medial aspect of ribs) thoracic and cervical vertebrae, mastoid process

Action:
o Bilateral: Extends the vertebral column and head
o Unilateral: Laterally flexes the vertebral column

Innervation: Posterior rami of spinal nerves

Question 10

Spinalis innervation

Answer 10

Innervation: Posterior rami of spinal nerves

Question 11

Identify this muscle

Answer 11

Longissimus

Question 12

Longissimus innervation:

Answer 12

Innervation: Posterior rami of spinal nerves

Question 13

Identify this muscle

Answer 13

iliocostalis

Question 14

Iliocostalis

Origin:
Insertion:
Action:
Innervation

Answer 14

Origin: broad tendon from posterior Iliac crest; sacral and inf. Lumbar spinous processes, and supraspinous ligament

Insertion: transverse processes of cervical vertebrae, lateral to longissimus on ribs

Action:
o Bilateral: Extends the spine + head
o Unilateral: Laterally flexes the spine

Innervation: Posterior rami of spinal nerves

Question 15

iliocostalis: action:

Answer 15

Action:
o Bilateral: Extends the spine + head
o Unilateral: Laterally flexes the spine

Question 16

iliocostalis innervation:

Answer 16

Innervation: Posterior rami of spinal nerves

Question 17

Semispinalis

Origin:
Insertion:
Action:
Innervation:

Answer 17

Origin: Transverse processes of C4-T12

Insertion: Spinous processes of cervical and thoracic vertebrae and occipital bone

Action:
o Bilateral: Extends the head, neck, and thoracic spine
o Unilateral: Rotates the head and spine to the opposite side (contralateral)

Innervation: Posterior rami of spinal nerves

Question 18

Identify this muscle

Answer 18

Semispinalis

Question 19

Semispinals action

Answer 19

Extends the head, neck, and thoracic spine
Rotates the head and spine to the opposite side (contralateral)

Question 20

Semispinalis innervation:

Answer 20

Posterior rami of spinal nerves

Question 21

Multifidus

Origin:
Insertion:
Action:
Innervation:

Answer 21

Origin: Sacrum, transverse processes of lumbar, thoracic, and cervical vertebrae

Insertion: Spinous processes of vertebrae 2-4 levels ABOVE origin

Action: Extension, lateral flexion and rotation of the vertebral column

Innervation: Posterior rami of spinal nerves

Question 22

Multifidus innervation:

Answer 22

Innervation: Posterior rami of spinal nerves

Question 23

Identify this muscle

Answer 23

Rotatores

Question 24

Rotatores

Origin:
Insertion:
Action:
Innervation:

Answer 24

Origin: Transverse processes of vertebrae

Insertion: Lamina of vertebrae immediately or 2 levels ABOVE origin

Action: Rotates vertebral column, functions to stabilize the vertebrae

Innervation: Posterior rami of spinal nerves

Question 25

Rotatores action:

Answer 25

Rotates vertebral column, functions to stabilize the vertebrae

Question 26

Rotatores innervation

Answer 26

Innervation: Posterior rami of spinal nerves

Question 27

Splenius Cervicis Origin: Insertion: Action: Innervation:

Answer 27

Origin: Spinous processes of T3-T6 Insertion: Transverse processes of C1-C4 Action: o Bilateral: Extends the cervical spine (head+neck) o Unilateral: Rotates and laterally flexes the neck to the same side Innervation: Posterior rami of cervical spinal nerves

Question 28

Intrinsic musculature only associated with (axial or appendicular skeleton) and innervated by (dorsal or ventral rami)

Answer 28

Intrinsic musculature only associated with *axial* skeleton and innervated by *dorsal rami*

Question 29

stretching or microscopic tearing of *muscle fibers*

Answer 29

strain

Question 30

most common back muscle (group) that is strain?

Answer 30

erector spinae (SLI muscles) group (d/t improper lifting technique, poor conditioning)

Question 31

erector spinale group (3)

Answer 31

1. spinalis 2. longissimus 3. iliocostalis

Question 32

only *ligamentous tissue* is involved in this injury

Answer 32

sprain

Question 33

most common sprain of the back?

Answer 33

anterior longitudinal ligament