Transcript Comprehensive Review Cranial Mechanics

Comprehensive Review Cranial
Mechanics
Darlene Myles D.O.
Block 8
Objectives
1. Review Cranial anatomy
2. Describe the basic components of the Cranial concept
3. Describe the major axes of motion in the Cranial base and
vault
4. Describe motion mechanics of the Cranium
5. Review SBS strain patterns
6. Review visual diagnosis of SBS strain patterns
Primary Respiratory Mechanism
(PRM)
5 Components to Model
1) Motility of CNS
2) Fluctuation of CSF
3) Mobility of intracranial /
intraspinal membranes
(reciprocal tension)
4) Articular mobility of cranial
bones
5) Involuntary motion of sacrum
between ilia
5 poles of attachment of the Dural
Membrane
1.
Anterior-superior pole
The falx attaches to the cristi galli of the
ethmoid and to the frontal crest
2.
3.
4.
5.
Anterior-inferior pole
The tentorium attaches to the anterior and posterior
clinoid processes of the sella turcica
Lateral poles
The tentorium attaches to the petrous ridge of the
temporal bone and the transverse ridge of the
occiput
Posterior pole
The internal occipital protuberance (opisthion)
Sacral pole
The dura exits the foramen magnum attaches to C2
and then hangs loosely until it attaches to the S2
sacral segment
Primary Respiratory Mechanism (PRM)
• Expansion and
Contraction of the CNS
discussed in relation to
what happens at the
major keystone joint of
the Cranial mechanism
(The SBS)
• During the expansion
phase the SBS Flexes
• During the Contraction
Phase the SBS Extends
SBS
Sphenobasilar Synchondrosis
Axes of Motion for Sphenoid and
Occiput
• AP Axis ( 1 axis)
– From Nasion through SBS to Opisthion
• Vertical Axes (2 axes)
– Through Foramen Magnum of the Occiput
– Through Body of the Sphenoid
• Transverse Axes ( 2 axes)
– Through Body of the Sphenoid
– Just above the Jugular Process on a level with
the SBS
Flexion
Extension
Cranial Bone Motion
• Each individual bone in the cranium has a predictable motion
based on bevel changes
• All Midline individual bones are said to either Flex or Extend
around a transverse axis
• All Paired bones are said to either internally rotate or
externally rotate
• During Flexion Phase all midline bones Flex
• During Flexion Phase all paired bones Externally Rotate
• During Extension phase all midline bones Extend
• During Extension phase all paired bones Internally Rotate
Articular … Cranial Bones - Sphenoid
Transverse axis through the center of its
body is in the area of the sella turcica
Vertical Axis through the center of its
body is in the area of the sella turcica
AP Axis through the center of its body is
in the area of the sella turcica AP Axis
•
The motion of the sphenoid occuring
in the sagittal plane described as
flexion and extension
Flexion:
– Posterior aspect of the body
elevates.
– The sella turcica moves
anterosuperiorly.
– Greater wings move forward and
slightly laterally and inferiorly.
– The pterygoids move posteriorly
and inferolaterally.
– The body expands a little as it
carries the resistance of the facial
bones.
• Primarily influences ethmoid,
vomer and facial bones
Articular … Cranial Bones - Occiput
Occipital Motion
The occiput has physiologic
motion of flexion & extension
in the sagittal plane around a
transverse axis, lying just
above the jugular processes.
Flexion
- the occipital base moves
superiorly
- the posterior aspect moves
posterior-inferiorl
- the occipital condyles
move anteriorly.
The occiput primarily influences
the parietals & temporal bones.
Articular … Cranial Bones – Temporal
•
•
•
•
The motion of the occiput is directly responsible for the motion of
the temporal bones.
The axis of physiologic motion runs from the jugular surface to the
petrous apex parallel to the petrous ridge.
In the flexion phase, the temporal bones externally rotate. The
squama moves anterolaterally and the mastoid portion moves
medially and slightly posteriorly.
In the extension phase, the reverse occurs
External Rotation
Internal Rotation
Articular Mobility of Cranial Bones
Articular … Cranial Bones - Frontal
Axis of rotation runs from the center of the
orbital plate up through the center of the orbital
eminence near the change of bevel at the cranial
border. Hinge-like action along the metopic
suture, remains a line of persisting flexibility.
In external rotation, the inferior lateral angles
(zygomatic angles) of the frontal bone move
laterally, inferiorly and slightly forward. The
opposite occurs in internal rotation.
–
The glabella tends to recede slightly in external
rotation due to the pull of the falx cerebri.
Articular … Cranial Bones - Parietal
•
Axis runs parallel to the sagittal
suture through the change of
bevel at the anterior & posterior
borders of each parietal bone
•
In external rotation, the inferior
borders of the parietal bone
moves laterally. A “widening”
occurs which is greatest at the
posterior aspect of the bones.
Internal rotation the inferior
borders move medially.
Parietal
Motions of Flexion and Extension
Flexion
Extension
• Midline Bones Flex
• Paired bones externally
rotate
• Bi-parietal diameter
increases
• AP diameter decreases
• Midline bones extend
• Paired bones internally
rotate
• Bi-parietal diameter
decreases
• AP diameter increases
Osteology
A few key relationships
Pterion
These four bones overlap in alphabetical order from within
outward
• Frontal - anterosuperiorly
• Parietal – posterosuperiorly
• Sphenoid –lateral surface of great
wing, anteroinferiorly
• Temporal - centrally
Frontal
Sphenoid
Parietal
Temporal
Netter Presenter: 2001.
Pterion
Strain Patterns
Patterns of the SBS
Strain Patterns
• Flexion
• Extension
• Torsion
– Right
– Left
• Side Bending Rotation
– Right
– Left
• Lateral Strain
– Right
– Left
• Vertical Strain
– Superior Strain
– Inferior Strain
• Compression
Physiologic Strain Patterns of SBS
• Flexion
• Extension
• Torsion
– Right
– Left
• Side Bending Rotation
– Right
– Left
Flexion - Extension
– Are the expected physiologic motions
– Can be pathological if restricted in one extreme or
another
Flexion/extension
Longer than usual cycle, typically (Similar to
prolonged exhalation in COPD)
Will have different feels at the ‘endpoints’ of the
Extension
phases
Will have decreased flow in the opposite phase
(e.g., flexion dysfunctions will have diminished
extension pattern)
Flexion
FLEXION
EXTENSION
ER
Flexion
•
•
•
•
Findings-all quadrants in external rotation
– Increased transverse diameter
– Forehead wide and sloping(brow prominent
with forehead receding)
– AP diameter equal on both sides
– Sagittal suture flattened or depressed
Sphenoid
– Superomedial-inferolateral diameter greater
– Orbits wider
– Eyeballs protuberant
– Increased fronto-zygomatic angle
– Frontal processes of maxillae are nearly in
coronal plane
– Maxillary palantine processes flattened
Occiput
– Protruding ears
– Mastoid tips posteromedial
Maxillae
–
Nasolabial crease deeper
ER
ER ER
Extension
•
Findings-all quadrants in internal rotation
–
–
–
•
Sphenoid
–
–
–
–
–
–
•
Superomedial-inferolateral diameter
decreased
Decreased frontozygomatic angle
Orbit narrowed
Eyeballs retruded
Frontal processes of the maxillae are nearly in
sagittal plane
Maxillary palantine processes arched
Occiput
–
–
•
Long narrow head
Decreased transverse diameter
Forehead prominent with Brow receding
Ears close to head
Mastoid tips anterolateral
Maxillae
–
Nasolabial crease shallow
IR
IR
IR
IR
TORSION
One axis
– Antero-superior to
Infero-posterior
– Spenoid and occiput
rotate in opposite
directions
– Named for superior
great wing of sphenoid
Torsion
•
Torsion of the sphenoid about an
anteroposterior (AP) axis extending
from the nasion through the
symphysis to opisthion
•
The sphenoid & anterior skull
components are in one direction, the
occiput & posterior components in
the other.
•
This strain is named for the side of
the high wing of the sphenoid, right
torsion (RT) or left torsion (LT)
Right Torsion
•
•
Findings- asymmetric quadrants
Sphenoid-1 quadrant in external
rotation
•
Higher greater wing
side relative to the
other
–
–
–
–
Orbit wide
Frontolateral angle anterior
Zygomatic orbital rim everted
Maxillary frontal processes in more
coronal plane
– Maxillary palantine processes flattened
•
Occiput-1 quadrant in external
rotation
•
Low occiput side
relative to the other
– Protruding ears
– Mastoid tips posteromedial
IR ER
IR ER
SIDEBENDING ROTATION
Two axes: A-P and
bilateral vertical axes
– Occiput and Sphenoid
rotate same direction
on AP axis; side-bend
away from each other
on parallel vertical
axes.
Named for convexity
Sidebending – Rotation Strain
•
Occurs around an AP axis & around 2
parallel vertical axes: one through the
body of the sphenoid & one through the
foramen magnum, perpendicular to the
physiologic transverse axes & the A-P
axis
•
As the SBS sidebends, it also rotates
inferiorly to the convex sidebending
side (coupled motion)
•
Named for the convex side of
sidebending
Lt Sidebending – Rotation Strain
Right Sidebending Rotation
• Findings- 1 side of face full and
convex with the opposite side
flattened (side of the lower greater
wing of the sphenoid)
• Sphenoid– Side of low greater wing in internal
rotation
•
•
•
•
•
•
Lateral fontal angle posterior
Orbit narrower
Eyeball retruded
Frontozygomatic angle lessened
Zygomatic tuberosity prominent
Maxillary frontal process more
sagittal
• Maxillary palantine process more
arched
• Occiput
• Mastoid tip –posteromedial
• Ear protruding
ER IR
IR ER
Non-physiologic Strain Patterns of SBS
• Lateral Strain
– Right
– Left
• Vertical Strains
– Superior Strain
– Inferior Strain
• Compression
LATERAL STRAIN
• Bilateral vertical axes
• Shearing force at SBS
causing Sphenoid and
Occiput to rotate same
direction on axes
• Named for position of
basisphenoid
• Head appears
“parallelogram”
Lateral Strain
•
Sphenoid and occiput have the same
rotation about a vertical axis, resulting
in a lateral strain pattern
•
Can happen with a one-sided impact
from the front or back of head (off-
center impact)
•
Named for the position of the base of
the sphenoid, relative to the occiput at
the SBS
•
Also known as “parallelogram head”
Left lateral strain
VERTICAL STRAINS
• Sphenoid and Occiput
rotate same direction
on parallel horizontal
axes
• Named for position
(superior/inferior) of
base of Sphenoid
Vertical Strain -Superior/Inferior
•
Sphenoid and occiput have the same rotation about a
transverse axis, resulting in a vertical strain pattern
•
Named for the position of the base of the sphenoid,
relative to the occiput at the SBS
Superior Shear
Inferior
Shear
Inferior
Shear
Superior Shear
Superior Shear
SBS Compression
•
Aka, ‘bowling ball head’
•
This is where the SBS has been
compressed (think of a ‘jammed’
finger), causing a near total lack of
motion at the SBS in any particular
direction
•
Most commonly seen in frontal
impact trauma, difficult births, and
circumferential loads to the skull, but
can also be seen in severe psychiatric
& emotional states
SBS
Patterns
Axes
A-P
Transverse
Vertical Paired
Naming
SB-Rot=Convexity
Torsion=High Gr Wing
Rest=Sphenoid Base Direction
Overview of Motions
• Occiput, sphenoid, ethmoid, vomer
– Rotate about a transverse axis during physiologic
Flexion and Extension
• Paired bones of the periphery
– Frontals, temporals, parietals, maxilla, palatines,
zygomae
– Rotate externally during cranial flexion
– Rotate internally during cranial extension
Observational Diagnosis
•
•
•
•
Flexion
Extension
Torsion
Sidebending Rotation
• Observational diagnosis
Observe face from the frontal and from
superior view of the head
Picture Effect on Internal/External
Rotation on Paired Bones of Face
Easiest: Flexion or Extension
Type
• Palate/Dental Arch:
– Extension = high & narrow
– Flexion = low & wide
Face affected most by Sphenoid;
Temporals & Sacrum by Occiput
Diagnosis by Visual Observation
•
•
•
•
•
Flexion
Extension
Orbit widens/ protrudes
Nasolabial crease deeper
Flattened Cheek
Ears – outflared
Decreased Frontal Eminence
•
•
•
•
•
– Sloping forehead
• Prominent Brow/Superciliary
ridge
Orbit narrows/ recedes
Nasolabial crease shallow
Cheek prominent
Ears- inflared
Increased Frontal Eminence
– Vertical forehead
• Receding Brow/Superciliary
Ridge
Vault Hold
• Pt supine, you gently place your hands
on the lateral aspects of the cranium
with the following landmarks:
– Index fingers in the temple (not
temporal) region, over the greater
wings of sphenoid
– Middle finger just in front of the
ear on the temporal bone
– Ring finger just behind the ear on
the temporal bone
– Little finger as close to the mastoid
portion of the occipitomastoid
suture as possible
– Thumbs gently resting on parietals
or frontal bone, wherever they fall
for your hands on the patient’s
skull
Flexion
Extension
Fronto-Occipital Hold
• Patient supine, with head at 3/4 of table.
• Physician at side of head of table.
• One hand cupping occiput.
• Other hand lightly palpating frontal bone
• General sensation is that of:
– Shortening of A/P axis with Flexion
– Elongation of A/P axis with Extension
Flexion = Shortening of
A/P axis
Extension = Lengthening
of A/P axis
Temporal Bone as “Trouble-Maker”
External
Rotation of
Temporal =
Pressure on
Trigeminal
Ganglion &
Tightens Cave
Cranial Nerves - Summary
Temporal Bone as “Trouble-Maker”
Olfactory Nerve - CNI
Hx: Blow to head
• Anosmia
• Altered sense smell
Physical:
• Ability to smell
• Frontal bone motion
• Also sphenoid, ethmoid, vomer
motion
Tx of Dysfunction: Frontal lift –
Ethmoid pump OMT
CN III, IV, VI Group:
Motor to Extra-Ocular Ms’s
III: Parasympathetic
(Accommodation)
Petrosphenoidal Ligament and its association with
CN III, IV, VI
Attached border of Tentorium
“Petrosphenoidal Ligament”
(Ligamentous thickening
from end of Petrous
Temporal to Sphenoid)
CN III over;
CN IV through;
CN VI under & at tip of the
temporal
External
Rotation
CNV - Trigeminal
• Structure
• Sensory to the Face
• Motor to the muscles of
mastication
• V1=SOF, V2=Foramen rotundum,
V3=Foramen ovale; Meckel’s cave,
petrosphenoid ligaments, Cervical
spine
• Dysfunction
• Anesthesia, Trigeminal neuralgia
(“Tic douleroux”)
• History
• Physical examination
• Trauma, Plagiocephaly
• Test sensation, corneal reflex
• Evaluate temporal (petrobasilar),
sphenoid
• Function
CN VII - Facial Nerve
• Function
• Structure
• Dysfunction
• Motor to facial muscles
Parasympathetic to glands
Special sense to tongue
• Stylomastoid foramen internal acoustic
meatus
• Paralysis, weakness, no or poor taste
sense
• Viral illness, trauma
• History
• Test facial expression, taste
• Physical examination • External rotation of temporal and
sphenoid bones
CN VIII - Vestibulocochlear Nerve
• Function
• Sensory - hearing and
balance
• Structure
• Dysfunction
• Internal acoustic meatus
• History
• Physical examination
• Hearing deficit, tinnitus,
vertigo, otitis media and
interna
• Trauma, infectious diseases
• Evaluation of temporals &
sphenoid; balance; hearing
CN IX - Glossopharyngeal Nerve
• Function
• Motor to muscle;
Parasympathetic to glands;
Sensory to palate
• Structure
• Jugular foramen
• Dysfunction
• History
• Physical examination
• Difficulties swallowing,
excessive gag reflex
• Trauma to occiput &/or
temporals
• Test gag reflex
• Evaluation of temporals,
occiput, occipitomastoid suture
CN X - Vagus Nerve
• Function
• Structure
• Dysfunction
• History
• Physical examination
• Motor to striated muscle;
Parasympathetic to smooth muscle
and glands; Sensory from viscera
• Jugular foramen, Foramen magnum
• Numerous Somatovisceral; Posterior
Headaches; More
• Trauma occiput, temporal
• Test gag reflex
• Evaluate OA, AA, C2, temporal,
occiput, OM suture
CN XI - Accessory Nerve
CN XI - Accessory Nerve
• Function
• Structure
• Dysfunction
• History
• Physical exam
• Motor
• Cervicals, Foramen magnum, Jugular
foramen
• Weakness/paralysis, torticollis;
Recurrent Trigger Points in SCM &
Trapezius
• Trauma to cervicals, occiput,
temporals
• Test SCM & Trapezius muscles;
Evaluate cervicals, occiput, temporals
CN XII - Hypoglossal Nerve
• Function
• Structure
• Dysfunction
• Motor to Tongue
• Hypoglossal canal
• Dysphagia, tongue
function
• History
• Trauma to occiput
(condyles)
• Physical examination
• Test tongue motions
• Evaluate occiput
(condyles), upper
cervicals
Questions?