3 Muscles of the Back Flashcards
extrinsic back muscles
**hypaxial
superficial extrinsic group
intermediate extrinsic group
I: ventral rami of spinal nerves
muscles of the superficial extrinsic group
trapezius latissimus dorsi rhomboid major rhomboid minor levator scapulae
trapezius
**superficial extrinsic group
O: nuchal ligament + spinous process C7 – T12
I: clavicle + medial border of scapula
A: elevate, retract, rotate scapula superiorly
N: CNXI + C3-C4
latissimus dorsi
**superficial extrinsic group
O: spinous process T7 – T12 + iliac crest + thoracolumbar fascia
I: intertubercular groove of humerus
A: extend, adduct, medially rotate humerus
N: thoracodorsal nerve
rhomboid major
**superficial extrinsic group
O: spinous process T2-T5
I: medial border of scapula
A: retract/rotate scapula inferiorly + fix scapula against thoracic wall
N: dorsal scapular nerve
rhomboid minor
**superficial extrinsic group
O: spinous process C7-T1
I: medial border of scapula
A: retract/rotate scapula inferiorly + fix scapula against thoracic wall
N: dorsal scapular nerve
levator scapulae
**superficial extrinsic group
O: transverse process C1 – C4
I: superior angle of scapula
A: elevate + rotate scapula inferiorly
N: dorsal scapular nerve
muscles of the intermediate extrinsic group
serratus posterior superior
serratus posterior inferior
serratus posterior superior
**intermediate extrinsic group
SA: nuchal ligament + spinal process C7 – T3
IA: superior border of ribs 2 – 4
A: elevate ribs
N: intercostal nerve 2 – 5
serratus posterior inferior
**intermediate extrinsic group
SA: spinal process T11 – L2
IA: inferior border of ribs 8-12
A: depress ribs
N: T9 – T12
(intrinsic) deep back muscles
**aka epaxial
superficial group
intermediate group
deep group
I: dorsal rami of spinal nerve
deep superficial group
splenius capitis
splenius cervicis
splenius capitis
**deep superficial group
O: nuchal ligament + spinal process C7 – T6
I: mastoid process
A: (bilateral) extend head/neck
(unilateral) lateral flexion of neck + ipsilateral rotation of head
N: dorsal rami
splenius cervicis
**deep superficial group
O: nuchal ligament + spinal process C7 – T6
I: transverse process C1 – C3
A: (bilateral) extend head/neck
(unilateral) lateral flexion of neck + ipsilateral rotation of head
N: dorsal rami
deep intermediate group
(erector spinae)
iliocostales
longissimus
spinales
**I Love Spaghetti
iliocostales
**deep intermediate group - erector spinae lateral (broadest)
O: posterior iliac crest + posterior sacrum + spinal process of lumbar/sacral vertebra
I: ribs + transverse process of cervical vertebrae
A: (bilateral) extend vertebral column y head/neck
(unilateral) ipsilateral flexion of vertebral column
N: dorsal rami
subtypes: lumborum, thoracis, cervicis
longissimus
**deep intermediate group - erector spinae middle
O: posterior iliac crest + posterior sacrum + spinal process of lumbar/sacral vertebra
I: ribs & transverse process of cervical/thoracic vertebrae
mastoid process
A: (bilateral) extend vertebral column y head/neck
(unilateral) ipsilateral flexion of vertebral column
N: dorsal rami
subtypes: thoracis, cervicis, capitis
spinales
**deep intermediate group - erector spinae medial (narrowest)
O: posterior iliac crest + posterior sacrum + spinal process of lumbar/sacral vertebra
I: spinal process of cervical/thoracic vertebrae
A: (bilateral) extend vertebral column y head/neck
N: dorsal rami
subtypes: thoracis cervicis
deep deep group
(transversospinalis group)
semispinalis
multifidus
rotatores
interspinales
intertransversarii
transversospinalis group
deep deep group
semispinalis
multifidus
rotatores
**Says Mama Ragu
semispinalis
**deep deep (transversospinalis) group
O: transverse process
I: spinal process of more superior vertebrae
A: contralateral rotation + (bilateral) extend y stabilize vertebral column
N: dorsal rami
subtypes: thoracis, cervicis, capitis
multifidus
**deep deep (transversospinalis) group
O: transverse process
I: spinal process of more superior vertebrae
A: contralateral rotation + (bilateral) extend y stabilize vertebral column
N: dorsal rami
powerful rotator
very meaty compared to rotatores
rotatores
**deep deep (transversospinalis) group
O: transverse process
I: spinal process of more superior vertebrae
A: contralateral rotation + (bilateral) extend y stabilize vertebral column
N: dorsal rami
powerful rotator
interspinales
**deep deep group
O: unite spinal process of consecutive vertebrae
I: unite spinal process of consecutive vertebrae
A: extend vertebral column
N: dorsal rami
intertransversarii
**deep deep group
O: unite transverse process of consecutive vertebrae
I: unite transverse process of consecutive vertebrae
A: (bilateral) extend vertebral column
(unilateral) ipsilateral flexion of vertebral column
N: ventral rami
subocciptal muscles
rectus capitis posterior major
rectus capitis posterior minor
obliquus capitis superior
obliquus capitis inferior
I: subocciptal nerve (dorsal rami)
FCN: posture, aid in head rotation
**direction of fibers gives clue toaction
rectus capitis posterior major
**suboccipital muscle
O: spinal process C2
I: inferior nuchal line (occipital bone)
A: (bilateral) extend @ C0 – C1
(unilateral) ipsilateral rotation @ C1 – C2
N: suboccipital nerve (dorsal ramus C1)
rectus capitis posterior minor
**suboccipital muscle
O: posterior arch C1
I: inferior nuchal line (occipital bone)
A: (bilateral) extend @ C0 – C1
(unilateral) ipsilateral rotation @ C1 – C2
N: suboccipital nerve (dorsal ramus C1)
obliquus capitis superior
**suboccipital muscle
O: transverse process C1
I: occipital bone
A: extension & lateral flexion of head
N: suboccipital nerve (dorsal ramus C1)
obliquus capitis inferior
**suboccipital muscle
O: spinal process C2
I: transverse process C1 (does not touch occipital bone)
A: ipsilateral rotation of head
N: suboccipital nerve (dorsal ramus C1)
