Trunk - Back Muscles

Question 1

Rectus Capitis Posterior Major

Answer 1

O: SP axis
I: lateral nuchal line occiput
A: extend & rotate head
N: suboccipital

Question 2

Rectus Capitis Posterior minor

Answer 2

O: posterior arch atlas
I: medial nuchal line occiput
A: extend head
N: suboccipital

Question 3

Obliquus Capitis inferior

Answer 3

O: SP axis (like R.C.Maj.)
I: TP atlas
A: rotate atlas
N: suboccipital

Question 4

Obliquus capitis superior

Answer 4

O: TP of atlas
I: nuchal line occiput (deep to R. Cap.
A: extend head
N: suboccipital

Question 5

Splenius capitis

Answer 5

O: SP of C7-T4
I: mandibular process - temporal bone
A: Head/neck extension, rotation, lat. flex
N: dorsal rami spinal nerves (C3-C5)

Question 6

Splenius cervicis

Answer 6

O: SP of T3-T6
I: TP of C1-C3
A: Head/neck extension, rotation, lat. flexion
N: dorsal rami of spinal nerves (C4-C8)

Question 7

Iliocostalis cerivicis

Answer 7

O: angles of ribs 3-6
I: TP of C4-C6
A: extend, lat. flex vert. column
N: dorsal rami of cervical spinal nerve

Question 8

Iliocostalis thoracis

Answer 8

O: angles ribs 6-12
I: TP C7, angles ribs 1-6
A: extend, lat. flex vert. column/head
N: dorsal rami of thoracic spinal nerve

Question 9

Iliocostalis lumborum

Answer 9

O: medial crest sacrum/iliac, lat. crest sacrum
I: angles or ribs 6-12
A: extend, lat. flex vert. column
N: dorsal rami of lumbar spinal nerve

Question 10

Longissimus capitis

Answer 10

O: TP of T1-T5 & articular process C5-C7
I: mastoid process
A: extend/rotate head
N: dorsal rami of cervical spinal nerve

Question 11

Longissimus cervicis

Answer 11

O: TP of T1-T5
I: TP of C2-C6
A: extend/lat. flex vert. column
N: dorsal rami of thoracic spinal nerve

Question 12

Longissimus thoracis

Answer 12

O: medial/lat. sacral crests, TP lower levels
I: TP of T1-T12 (all)
A: extend/lat. flex vert. column
N: dorsal rami lumbar spinal nerve

Question 13

Spinalis cervicis

Answer 13

O: Lig. nuchae, Sp of C7
I: SP of C2
A: extend vert. column/head
N: dorsal primary div. of spinal nerves

Question 14

Spinalis thoracis

Answer 14

O: SP of T11, T12, L1, L2
I: SP of T1-T8
A: extend vert. column
N: dorsal primary division of spinal nerves

Question 15

Semispinalis capitis

Answer 15

O: AP of C7, TP of T1-T6
I: inf.-sup. nuchal line
A: extend/contralateral rotation of the head/neck
N: dorsal rami of cervical spinal nerves

Question 16

Semispinalis cervicis

Answer 16

O: TP of T1-T6
I: SP of C2-C5
A: vert. column extension, contralateral rotation
N: dorsal rami of thoracic spinal nerves

Question 17

Semispinalis thoracic

Answer 17

O: TP of T6-T10
I: SP of C6, C7, T1-T4
A: extend vert. column, contralat. rotation
N: dorsal rami of the lumbar spinal nerves

Question 18

Multifidis

Answer 18

O: laminae (mammilary process) S4-C2. possibly absent in thoracic
I: SP of superolat. 2-4 vertebra
A: extend/stabilize vert. column, lat. flexion and contralateral rotation vert. column
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves

Question 19

Rotatores

Answer 19

O: TP entire vertebra
I: base SP (brevis = up 1)(longus=up 2)
A: stabilize vert. contralat. rotation
N: dorsal rami of cervical, thoracic, and lumbar spinal nerves

Question 20

Levator costarum

Answer 20

O: TP tip of thoracic vert.
I: inferolat. to angle of adjacent rib
A: elevate ribs during inspiration
N: ventral rami of thoracic spinal nerves

Question 21

Quadratus lumborum

Answer 21

O: iliolumbar lig. internal lip of iliac crest
I: TP tips of lumbar vert. inferior border rib 12
A: extend/lat. flex vert. column, fix rib 12 for inspiration
N: Branches of ventral rami of T12, L1-4

Question 22

Psoas major

Answer 22

O: TP of lumbar vert., sides of body for T12-L5 & intervert. discs
I: Lesser trochanter femur
A: increase lumbar lordosis, lat flex, flex hip/pelvis on trunk
N: lumbar plexus, branches of primary dental rami of L1-L4