Muscles of the back (Intermediate and Deep) Flashcards
What are the superficial layer muscles on the back? (4). What do they connect?
Trapezius (upper, middle, lower), Latissimus dorsi, levator scapula, rhomboid major (minor)
They connect the upper limb to the trunk
What are the intermediate layer muscles on the back?
serratus posterior superior
- serratus posterior inferior
2 muscles on the posterior thorax - accessory muscles of respiration
Of the deep muscles on the back, how many layers are there?
3
Of the deep muscles on the back which are on the superficial layer? (2)
splenius capitis
splenius cervicis
Of the deep muscles on the back which are in the intermediate layer?
What are they collectively called?
Collectively called erector spinae (aka paraspinals). MEDIAL to LATERAL they are:
- spinalis
- longissimus
- iliocostalis
Of the deep muscles on the back which are the deepest layer?
superomedial fiber direction: from SUP to DEEP
- semispinalis (capitis, cervicis, thoracis)
- multifidus
- rotatores
vertical fibre direction:
- interspinales
- intertransversarii
Serratus Posterior Superior
Deep to rhomboids superficial to erector spinae Med attach: SPs of C7-T3 Lat attach: superior borders of ribs 2-5 action: elevates ribs 2-5 with deep inspiration superomedial
Serratus Posterior Inferior
Deep to latissimus/thoracolumbar fascia superficial to the erector spinae Med attach: SPs of T11 - L2 Lat attach:L lower 4 ribs action: draws ribs down and back during forced exhalation (ie coughing, sneezing, Superolateral
Splenius Capitis
Deep layer - superficial
Superior attach: mastoid process and lateral superior nuchal line
Inferior attach: SPs of C4-T2
action: unilateral ipsilateral rotation
action: bilateral extension of the neck
Splenius cervicis
Deep layer - superficial
Superior attach: C1-C4 TVPs (posterior tubercles)
Inferior attach: SPs of T3 - T5
action: unilateral ipsilateral rotation
action: bilateral extension of the neck
What, collectively are the intermediate layer of the deep back muscles called? What fibre direction do they run?
Erector Spinae muscles. superolateral
Spinalis (Erector spinae group)
Deep layer - intermediate
shortest and thinnest of the paraspinals sit in the laminar groove (btwn the SPs and TVPs) attach to SPs most medial of the 3 intermediate muscles 3 segments - thoracis (SPs of upper thoracic spine) - cervicis - capitis
actions: unilateral lateral flexion of vertebral column
actions: bilateral extension of the vertebral column
(eccentric contraction would be a controlled forward flexion of the spine)
Longissimus (Erector spinae group)
Deep layer - intermediate
longest column most easily seen/ palpated attach to TVPs 3 columns: - thoracis (TVPs of thoracic spine) - cervicis (TVPs of cervical spine) - capitis (mastoid process)
actions: unilateral lateral flexion of vertebral column
actions: bilateral extension of the vertebral column
(eccentric contraction would be a controlled forward flexion of the spine)
Iliocostalis (erector spinae group)
Deep layer - intermediate
most easily palpable through lumbar attach to angles of the ribs 3 columns: - lumborum (angle of ribs 8-12) most palpable - thoracis (angle of ribs 1-7) - cervicis (TVPs of C3-6)
actions: unilateral lateral flexion of vertebral column
actions: bilateral extension of the vertebral column
(eccentric contraction would be a controlled forward flexion of the spine)
Semispinalis
Deep layer - deep
most superficial covers half of the spinal column skip 3-6 vertebrae i) thoracis ii) cervicis iii) capitis attaches superiorly to the occipital bone between the superior and inferior nuchal lines largest mass in the posterior neck
actions: bilateral extension of the head and neck
actions: unilateral contralateral rotation of the neck
fibre direction: superomedial
