Deep Muscles of Back

Question 1

Thoracolumbar fascia (3)

Answer 1

• surrounds deep muscles of back
• continuous w/deep fascia in neck
• deep to serratus posterior muscles

Question 2

Thoracolumbar fascia - posterior layer of lumbar region (3)

Answer 2

• LV + SV SP
• supraspinous lig
• cover erector spinae

Question 3

thoracolumbar fascia - middle layer of lumbar region (3)

Answer 3

• LV + IT lig
• inferiorly - IC
• superiorly - rib 12

Question 4

thoracolumbar fascia - anterior layer of lumbar region (4)

Answer 4

• anterior - quadratus lumborum (abs)
• medially - LV TP
• inferiorly - IC
• superiorly - lig for diaphragm

Question 5

Splenius Capitis (ST muscle) (4)

Answer 5

• origin = C7 SP to T4 TP
• insertion = MP, SNL
• innervation = post rami
• fn = both extend neck, individually - head to same side

Question 6

splenius cervicis (ST muscle) (4)

Answer 6

• origin = T3-T6 SPs
• insertion = C1-C3 TPs
• Innervation = post rami
• function = together - extend neck, individually - rotate to same side

Question 7

erector spinae muscles (3)

Answer 7

• largest intrinsic muscles
• from SV, LV + TV SPs + IC
• divides lumbar area into 3 vert muscle columns - ILS (from lateral to spinal)

Question 8

erector spinae muscle function (2)

Answer 8

• main fn = extend VC + head, straighten back when flexed

- unilaterally = bend VC laterally, turn head to contracting side

Question 9

iliocostalis (3)

Answer 9

lumborum (SV -> ribs)
thoracis (angles of ribs -> ribs)
cervicis (angles of ribs -> CV TPs )

Question 10

longissimus (TPs) (3)

Answer 10

thoracis (SV -> TP)
cervicis (lower TPs to higher CV TPs)
Capitis (CV TPs to MP TPs)

Question 11

spinalis (SPs) (3)

Answer 11

thoracis (SV -> TV)
cervicis (TV -> CV)
capitis (semispinalis)

Question 12

TS muscles (4)

Answer 12

• TP to SP
• deep to erector spinae
• 3 subgroups = semispinalis, multifidus, rotatores muscles
• fn = extend VC bilaterally, or SPs to TPs unilaterally = trunk rotates in opp direction

Question 13

semispinalis (5)

Answer 13

• most superficial of TS
• CV + TV TP -> SNL/INL
• cross btwn 4-6 vert
  all TPs -> SPs
• greater occiptal nerve

Question 14

multifidus (4)

Answer 14

• deep to semispinalis
• span length of VC (TPs to SPs), btwn 2-4 vert
• best developed in LV
• origin of erector spinae

Question 15

rotatores (3)

Answer 15

deepest, span VC, best developed in TV
long rotators = TPs to SPs crossing 2 vert
short rotators = attach to adjacent vert

Question 16

levatores costarum (3)

Answer 16

origin = C7->T11 TPs
insertion = rib below vert of origin
fn = elevates rib
innervation = posterior rami

Question 17

interspinales (3)

Answer 17

between SPs
assist w/posture
innervated by dorsal rami

Question 18

intertransversarii (4)

Answer 18

btwn TPs
assist w/posture
innervation by dorsal rami
modified in thoracic region to levator costarum

Question 19

Suboccipital muscles (4)

Answer 19

• connect C1 to C2, and both to skull base
• contraction extends head at atlanto-axial joint
• innervated by post rami of C1
• blood supply from vert + occipital arts

Question 20

rectus capitis posterior (RCP) major (2)

Answer 20

• C2 SP -> base of skull

- fn = head extension, rotation of to same side

Question 21

rectus capitis posterior (RCP) minor (3)

Answer 21

• posterior tubercle of C1 -> INL

- fn = head extension

Question 22

obliquus capitis superior (OCS) (3)

Answer 22

C1 TP -> INL

- fn = head extension, bend to same side

Question 23

obliquus capitis inferior (OCI) (3)

Answer 23

C2 SP -> C1 TP

fn = face rotation to same side

Question 24

suboccipital triangle (4)

Answer 24

• vert art + post ramus exit above C1
• supply suboccipital triangle muscles
• greater occipital nerve = C2
• lesser occipital nerve = C1

Question 25

Suboccipital triangle borders (3)

Answer 25

RCP major = medial border of triangle

• OCS = lateral border
• OCI = inferior border