Muscles of the Face

1
Myology
Muscles of the Posterior Trunk
2
Latissimus Dorsi

• Fibers of the latissimus dorsi twist in such a
  way that the superior fibers attach distally on
  the humerus and the inferior fibers attach
  proximally.
• Sometimes the latissimus blends with the teres
  major
• The spinal and pelvic attachments are all via
  thoracolumbar fascia.
• Since it has an attachment onto the inferior
  angle of the scapula, it can move the scapula.
  When trunk is fixed, it can depress, retract and
  downwardly rotate the scapula.
• If the arm is fixed, the lat can elevate the
  trunk at the shoulder joint toward the humerus
  (as in a pull up).
• The latissimus dorsi and pectoralis major are
  both large powerful muscles which attach trunk to
  the arm. The both adduct and medially rotate the
  humerus.

3
Latissimus Dorsilatissimus widedorsi back

• O Thoracolumbar aponeurosis, posterior sacrum,
  posterior iliac crest, lower 3 or 4 ribs, and
  inferior angle of the scapula
• I Medial lip of the Bicipital Groove of the
  humerus
• A Extends, medially rotates, adducts the arm
  (handcuff position)
• Reversed muscle action bilaterally causes
  anterior tilt of the pelvis. Unilateral
  contraction causes elevation of the pelvis,
  contralateral rotation of the trunk, and lateral
  deviation of the trunk.
• N Thoracodorsal nerve

Palpation Page 207
4
Rhomboids

• They are deep to the trapezius
• Rhomboid minor is superior to rhomboid major.
• Rhomboid minor attaches to the scapula, inferior
  to the levator scapulae.
• Deep to the rhomboids are the splenius capitis,
  splenius cervicis, serratus posterior superior
  and erector spinae
• They also cause downward rotation of the scapula.
• Are sometimes called Christmas Tree muscles due
  to their shape.
• Rounded Shoulders is a common condition in which
  scapulae are protracted (abducted) and depressed
  and the humeri are medially rotated. When
  rhomboids are weak, the can contribute to this
  condition. This is especially true if the
  protractors (pecs) are tight.

5
Rhomboid Major and Minor

• O Rhomboid Major Sps T2-T5
• Rhomboid Minor Sps C7-T1
• I Medial border of the scapula from the root
• of the spine of the scapula to the inferior
• angle of the scapula
• A Retracts, elevates, and downwardly
• rotates the scapula.
• Reversed muscle action Unilaterally
• causes contralateral rotation of the trunk
• N Dorsal scapular nerve

Palpation Page 212
6
Serratus Anterior

• Majority of this muscle lies deep to the scapula
  and lats posteriorly and pecs anteriorly.
• Lowest 4-5 slips of costal attachments
  interdigitate with external oblique.
• Lies next to (anterior to) the subscapularis.
• Serrated appearance comes from attaching onto
  separate ribs, which creates the notched look of
  a serrated knife.
• Prime mover of protraction, upward rotation,
  medial tilt of scapula.
• Required during forceful protraction of scapula
  i.e. reaching, pushing, punching, throwing.

7
Serratus Anterior

• O Outer borders of the 1st through 9th ribs
• I Anterior surface of the entire
• medial border of the scapula
• A (PUSS) Protracts, upwardly
• rotates, and stabilizes the
• scapula
• N. Long thoracic nerve (of Bell)

Palpation Page 215
8
Serratus Posterior Superior

• Thin, quadrilateral shaped muscle
• Important for respiration specifically
  inspiration since it elevates ribs 2-5 increasing
  the size of the thoracic cage (Boyles Law).
• Lies deep to the rhomboids

9
Serratus Posterior Superior

• O SPs of C7-T3
• I Superior borders of Ribs 2-5 (deep to the
  rhomboids)
• A Elevation of ribs 2-5
• N intercostal nerves

Palpation Page 219
10
Serratus Posterior Inferior

• O SPs of T11-L2
• I Inferior borders of Ribs 9-12
• A Depression of ribs 9-12
• N subcostal intercostal nerves

Palpation Page 221
11
The Erector Spinae Group

• Name tells us that these muscles make the spine
  erect.
• Lie deep in the back and neck
• In lumbar region, this group is deep to the lat
  and serratus posterior inferior.
• In thoracic region, deep to trap, lats,
  rhomboids, serratus posterior superior, splenius
  capitis splenius cervicis.
• In cervical region, deep to trap, splenius
  cap/cerv, and SCM
• In trunk, erector spinae are superficial to
  transversospinalis group, QL, and ribcage.
• In neck erector spinae group is superficial to
  suboccipitals.
• Spinalis, longissimus, and iliocostalis make up
  erector spinae group.
• From medial to lateral the acronym SLI name the
  muscle of the group

12
Erector Spinae Group(Overview of entire group)

• O Pelvis
• I Spine, ribcage, head
• A Bilateral Contraction causes
• Extension of the trunk, neck, and
• head anterior pelvic tilting.
• Unilateral contraction causes
• lateral flexion and Ipsilateral
• rotation of the trunk, head, and
• neck elevation of the pelvis
• N Dorsal rami of the spinal nerves

13
Individual Erector Group Muscles

• Iliocostalis
• Subdivided into lumborum, thoracis, and cervicis
• Most lateral of the three
• Longissimus
• Subdivided into thoracis, cervicis, and capitis
• Longest largest of the three with most superior
  attachments.
• Spinalis
• Subdivided into thoracis, cervicis, and capitis
• Most medial of the three

14
Iliocostalis

• O Iliocostalis Lumborum Medial iliac crest and
  sacrum
• Iliocostalis Thoracis angles of ribs 7 12
• Iliocostalis Cervicis angles of ribs 3-6
• I Iliocostalis Lumborum angles of ribs 7 12
• Iliocostalis Thoracis angles of ribs 1-7
  and C7 TP
• Iliocostalis Cervicis TPs of C4 C6
• A Bilateral contraction Extends the trunk and
  neck and anteriorly tilts the pelvis.
• Unilateral contraction Lateral flexion and
  ipsilateral rotation of the trunk and neck
  elevation of the pelvis at the lumbosacral joint.
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Palpation Page 227
15
Longissimus

• O Longissimus Thoracis Medial iliac crest,
  posterior sacrum, and TPs of L1 L5
• Longissimus Cervicis TPs of T1 T5
• Longissimus Capitis TPs of T1 T5 and the
  APs of C5 - Ct
• I Longissimus Thoracis TPs of all thoracic
• vertebrae and the 9 lower ribs
• Longissimus Cervicis TPs of C2 C6
• Longissimus Capitis Mastoid process
• A Bilateral contraction Extends the trunk and
  neck and anteriorly tilts the pelvis.
• Unilateral contraction Lateral flexion and
  ipsilateral rotation of the trunk, neck, and
  head elevation of the pelvis at the lumbosacral
  joint.
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Palpation Page 230
16
Spinalis

• O Spinalis Thoracis SPs of T11 T12
• Spinalis Cervicis Inferior nuchal ligament
  and SP of
• C7
• Spinalis Capitis Usually considered to be part
  of
• the semispinalis capitis
• I Spinalis Thoracis SPs of T4 T8
• Spinalis Cervicis SP of C2
• Spinalis Capitis Usually considered to be part
  of the semispinalis capitis
• A Bilateral contraction Extends the trunk and
  neck.
• Unilateral contraction Lateral flexion and
  ipsilateral rotation of the trunk, neck, and head
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Palpation Page 233
17
(No Transcript)
18
Transversospinalis Group (Overview of entire
group)

• O Pelvis
• I Spine head
• A Bilateral contraction Extension of the head,
  neck, and trunk and Anterior tilting of the
  pelvis
• Unilateral contraction Lateral flexion of the
  head, neck, and trunk Contralateral rotation of
  the neck and trunk
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

19
Transversospinalis Group

• Very deep in the back and lie in the laminar
  groove (over the laminae between the SPs/TPs)
• In trunk, directly deep to the erector spinae
  group
• In neck, deep to trap, SCM, splenius capitis.
• Name tells us that this group attaches from TP
  (transverso) to SP (spinalis). The transverse
  process attachment is inferior with the spinous
  process attachment superior.
• Subdivided, superficial to deep into
  semispinalis, multifidus, and rotatores.
• Semispinalis attaches superiorly to vertebrae 5
  or more levels above
• Multifidus attaches superiorly 2-4 levels
• Rotatores attach superiorly 1-2 levels.
• Only multifidus attaches onto pelvis.
• Only semispinalis attaches onto head.
• The term paraspinal musculature is used to
  describe erector spinae and transversospinalis
  groups.

20
Semispinalis

• O Semispinalis Thoracis TPs T6-T10
• Semispinalis Cervicis TPs T1 T5
• Semispinalis Capitis TPs of C7 T6
• and the APs of C4 C6
• I Semispinalis Thoracis SPs of C6 T4
• Semispinalis Cervicis SPs of C2 C5
• Semispinalis Capitis Occiput
• A Bilateral contraction Extension of the head,
  neck, and trunk
• Unilateral contraction Lateral flexion of the
  head, neck, and trunk Contralateral rotation of
  the neck and trunk
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Palpation page 240
21
Multifidus

• O Posterior sacrum, PSIS, L5-C4
• I SPs 2-4 levels superior to inferior
  attachment
• A Bilateral contraction Extension of the neck
  and trunk Anteriorly tilts the pelvis.
• Unilateral contraction Lateral flexion of the
  neck, and trunk Contralateral rotation of the
  neck and trunk Elevates the pelvis.
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Palpation page 243
22
Rotatores

• O TPs of the lumbar, thoracic, and cervical
  vertebrae
• I Lamina of the vertebrae one to two levels
  above
• A Bilateral contraction Extension of the neck
  
• and trunk
• Unilateral contraction Contralateral rotation
  of the neck and trunk
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Not palpable
23
Quadratus Lumborum

• Refer to as QL
• Very deep and forms part of posterior abdominal
  wall
• Majority deep to erector spinae
• Must be accessed with palpation from lateral to
  medial (i.e. come in from the side).
• Can elevate the pelvis. Often the term hiking
  the hip is used to describe the action.

24
Quadratus Lumborum

• O Rib 12, L1-4 TPs
• I Posterior Iliac Crest.
• A Bilateral contraction Extension of trunk
  anterior tilting of the pelvis
• Unilateral contraction Lateral trunk flexion
  hiking up of the hip depression of the 12th
  rib
• N Lumbar plexus

Palpation page 248
25
Interspinals

• Paired muscles that are located on either side of
  the interspinous ligaments between the apices of
  the SPs of adjacent vertebrae.
• Located deep to supraspinous ligament (nuchal
  ligament in cervical region).
• Not located throughout entire spine. Primarily
  found in cervical lumbar regions.
• May be important at fixating the spine.

26
Interspinals

• O From a SP
• I SP directly superior (not well developed or
  absent in the thoracic spine)
• A Extension of neck and trunk
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Palpation page 251
27
Intertransversarii

• Located between TPs and very deep.
• Attach onto anterior tubercles and posterior
  tubercles of TPs in cervical spine.
• Do not exist in thoracic region since levator
  costarum and intercostals take their place.
• Important as fixators of spine (stabilize)

28
Intertransversarii

• O From a TP of a vertebrae
• I TP directly superior (in the thoracic region
  these muscles are found between T10 and L1)
• A Lateral flexion of neck and trunk
• N Dorsal rami of the cervical, thoracic, and
  lumbar spinal nerves

Not palpable
29
Levator Costarum

• O TPs of C7-T11
• I Rib 1-12 (inferiorly)
• A Elevation of ribs (primary action). In
  addition contributes to extension of the trunk
  when contracting bilaterally and lateral flexion
  of the trunk when contracting unilaterally
• N Dorsal rami of the thoracic spinal nerves

Not palpable
30
Which muscle of the deep spinal group performs
rotation?

1. interspinalis
2. intertansversari
3. rotatores
4. deep spinal

31
Levator Costarum

• Name tells us that the elevate the ribs
• Attach from vertebrae TP and run inferolaterally
  on to rib directly inferior.
• Controversy as whether they are respiratory
  muscles that move ribs or move/fixate spinal
  joints

32
Subcostales

• Usually well developed in lower thoracic region.
• Lie deep to the ribcage and superficial to the
  plural membrane.
• Thought to be respiratory muscles which depress
  the ribs for forced expiration.

33
Subcostales

• O Ribs 10-12
• I Rib 8-10
• A Depression of ribs 8-10
• N Intercostal nerves 8 -11

Not palpable