Module 3: FAB Back Muscles

muscles of the superficial layer

trapezius, latissimus dorsi, thoracolumbar fascia

origin of trapezius

EOP, inion superior nuchal lines, nuchal ligaments and SPs T1-T12

insertion of trapezius

spine and acromion of scapula, lateral 1/3 of clavicle

action of trapezius

retraction, elevation and upward rotation of scapula

ipsilateral flexion and extension and contralateral rotation of the neck

innervation of trapezius

CN XI (accessory nerve), C3-C4 cervical plexus

handcuff muscle

latissimus dorsi

Latissmus Dorsi Origin

SPs of T6-L5, sacrum and ilium through fascia, inferior angle of scapula

latissimus dorsi insertion

intertubercular groove of humerus

latissimus dorsi action

adduction, internal rotation and extension of humerus

latissimus dorsi innervation

thoracodorsal nerve

thoracolumbar fascia

T6-T12, L1-L5, sacrum and coccyx

Second layer of back muscles

rhomboid major, rhomboid minor, levator scapulae

rhomboid minor origin

SPs C7-T1

rhomboid minor insertion

root of scapular spine

rhomboid minor and major and levator scapulae action

retraction, elevation and downward rotation of scapula

innervation of rhomboid minor and major and levator scapulae

dorsal scapular nerve

rhomboid major origin

SPs of T2-T5

rhomboid major insertion

medial border of scapular below the roots

levator scapulae origin

TPs C1-C4

levator scapulae insertion

medial border of scapula above roots

muscles of the third layer

serratus posterior superior and serratus posterior inferior

serratus posterior superior origin

SPs C7-T3

serratus posterior superior insertion

upper ribs

serratus posterior superior action

elevates ribs

serratus posterior superior and serratus posterior inferior innervation

Ventral primary rami

serratus posterior inferior origin

SPs T11-L2

serratus posterior inferior insertion

lower ribs

serratus posterior inferior action

depresses ribs

fourth layer back muscles

splenius capitis and splenius cervicis

splenius capitus origin

SPs C3-T3

splenius capitus insertion

mastoid process

splenius capitus and splenius cervicis action

Ipsilateral rotation, ipsilateral flexion, extension of neck

the muscles of layers 4-6 are innervated by the

dorsal primary rami

splenius cervicis origin

SPs T3-T6

splenius cervicis insertion

TPs C1-C4

splenius capitus and splenius cervicis innervation

dorsal primary rami

the fifth layer back muscles

Illicostalis, longissmus, spinalis

three Illicostalis muscles

lumborum, thoracis, cervicis

Illicostalis lumborum origin

sacrum and ilium

illicostalis lumborum insertion

lower ribs

Illicostalis lumborum action

extend and laterally flex spine

illicostalis thoracis origin

lower ribs

Illicostalis thoracis insertion

upper ribs

Illicostalis thoracis action

extend and laterally flex spine

Illicostalis Cervicis origin

upper ribs

Illicostalis Cervicis insertion

TPs lower cervical

Illicostalis cervicis action

extend and laterally flex spine

Illicostalis cervicis, Illicostalis thoracis Illicostalis lumborum innervation

dorsal primary rami

Longissimus muscles

thoracis, cervicis, capitus

longissmus thoracis origin

ilium, sacrum, TPs L1-L5

longissmus thoracis insertion

TPs Lower

longissmus thoracis action

extend and laterally flex spine

spinalis muscles

capitis, cervicis, thoracis

spinalis thoracsis origin

SPs lower thoracic

spinalis thoracsis insertion

SPs lower cervical

spinialis thoracis action

extend spine

spinialis cervicis origin

SPs upper thoracic

spinialis cervicis insertion

SPs of upper thoracic and lower cervical

spinalis cervicis action

extend spine

spinalis capitis origin

SPs upper cervical

spinalis capitis insertion

EOPs

spinalis capitis action

Extend head

longissimus cervicis origin

TPs upper thoracic

longissimus cervicis insertion

TPs lower cervicle

longissimus cervicis action

extend and laterally flex spine

longissimus capitis origin

TPs upper cervical

longissimus capitis insertion

mastoid process

longissimus capitis action

extend and laterally flex spine

semispinalis thoracis origin

TPs of thoracic

semispinalis thoracis insertion

SPs 4-6 vertebral segments superior

semispinalis thoracis action

extension, ispi flexion, contra rotation

semispinalis cervicis origin

TPs T1-T5, articular process C4-7

semispinalis cervicis insertion

SPs 4-6 vertebral segments superior

semispinalis cervicis action

extension, ipsi flexion, contra rotation

semispinalis capitis origin

TPs C7-T6

semispinialis capitis insertion

occiput between medial portions of superior and inferior nuchal line

semispinialis capitis action

extension, ipsi flexion, contra rotation

multifudus origin

TPs of spinal region

multifudus insertion

SPs 2-4 segments above

multifudus action

extension, ipsi flexion, contra rotation

rotatores origin

transverse processes

rotatores insertion

Longus - SP 2 segments superior; brevis -SP 1 segment superior

rotatores action

extension, ipsi flexion, contra rotation

intertransversarii origin

transverse processes of vertebrae

Intertransversarii insertion

transverse processes of adjacent vertebrae

intertransversarii action

ipsilateral lateral flexion

intertransversarii innervation

primary dorsal rami

interspinalis origin

SP below

interspinalis insertion

SP above

interspinalis action

ipsi lateral flexion

interspinalis innervation

dorsal rami

levator costarum origin

transverse processes of C7-T11

levator costarum insertion

brevis- rib below longus - second rib below

levator costarum action

elevates ribs

rectus capitus posterior minor origin

inferior nuchal line

rectus capitus posterior minor insertion

posterior tubercle of C1

rectus capitus posterior minor action

extension, ipsilateral rotation and ipsilateral lateral flexion

rectus capitus posterior minor

rectus capitus posterior major

obliquis capitus inferioris

obliquis capitus superiorius

innervation

suboccipital nerve

rectus capitus posterior major origin

inferior nuchal line

rectus capitus posterior major insertion

SPs of C2