Cranial Midline Bones Flashcards
Principles of Treatment for cranial dysfunction
- find greatest restricted pattern of dysfunction (soma, cranium)
- direct: force into barrier
- indirect: balanced membranous tension; encourage amplitude of dynamic motion
Qualities of the CRI
- R-RADS
- rate, rhythm, amplitude, direction, strength
Vault hold
- patient supine
- doc seated at head of table
- index fingers on greater wings of sphenoid
- little fingers on occiput
- long and ring fingers surround the pinna of the ear
- thumbs off the calvarium
Frontal occipital hold
- patient supine with doc seated to side of table at head
- one hand contacts greater wing of sphenoid with thumb and long or little finger
- other hand cups occciput
Normal motion of the SBS: flexion
- greater wings of sphenoid move anterior/inferior
- squamous portion of occiput moves posterior/inferior
- SBS moves superior/cephalad
- cranium changes: shorter A/P and superior/inferior diameters
- wider in R/L diameter
SBS extension
-motions and dimensions are opposite of flexion
Flexion dysfunction of the SBS
-freedom of active and passive motion testing is toward flexion with little motion (i.e. restriction) toward extension phase
Extension dysfunction of the SBS
-freedom of active and passive motion testing is toward extension with little motion (i.e. restriction) toward flexion phase
Sacral nutation
-sacral base moves anterior during SBS extension phase of CRI
Sacral counternutation
-sacral base moves posterior during SBS flexion phase of CRI
Balanced Membranous Tension
- indirect cranial manipulative treatment
- for any dysfunction, determine the extent of range of motion in all directions applicable
- using a hold, you will place the SBS or other cranial bones/joints in the midpoint of the available ROM
- the CRI will move against your force but you should resist changing your force
- the CRI will dampen to the point of you not being able to feel the motion–called still point
- maintain your concentration and when you feel the CRI return it will return in a more symmetrical motion than before
During the still point
- the membranes that were tight are relaxing and those that were lax are tightening up
- once this is accomplished, the CRI mechanism “catches up” and starts producing a more even palpation experience of the CRI
- the dysfunctional motion will be restored to a more normal motion pattern
Motion of sphenoid
-greater wings move anterior/inferior during flexion and reverse during extension
Motion of occiput
-membranous portion of the occiput moves posterior/inferior during flexion and reverses during extension
Motion of SBS
-SBS moves cephalad during flexion and caudad druing extension
Cranial midline or unpaired bones
- Ethmoid
- Occiput
- Sphenoid
Facial midline or unpaired bones
- mandible
- vomer
Cranial paired bones
- parietal
- temporal
- frontal
Facial Paired bones
Inferior nasal concha
- lacrimal
- maxilla
- nasal
- palatine
- zygoma
Midline bones motion
- usually rotate about a transverse axis in an anterior/posterior direction (even when it is labeled flexion-extension)
- in sagittal plane
Paired bones motion
-usually move about AP axis in a lateral motion (coronal plane), labeled external/internal rotation (flexion-extension)
Basic motion of the SBS
- inhalation=flexion
- sphenoid will rotate about a transverse axis so that the alae (wings) will move anteriorly and the motion at the SBS will be superior
- Occiput will rotate about a transverse axis so that the motion at the SBS will be superior and the bowl of the occiput will move posterior/inferior
Sphenoid rotates
on a transverse axis through the center of the body at the level of the floor of the sella turcica
- greater wings move anterior, slightly laterally and inferiorly, influencing the lateral edges of the frontal bone anteriorly and laterally
- the pterygoid process move posteriorly and slightly internally
Occiput in flexion
- rotates about a transverse axis directly superior to foramen magnum at the level of confluence of sinuses
- as it rotates, the basilar part and the condyles move anteriorly and superiorly, directly influencing the temporal bones and the scam moves posteriorly and slightly laterally
- greatest lateral deviation occurs at the lateral angles
SBS motion–ethmoid
-the basiocciput will move vertically in sphenobasilar symphysis (SBS) flexion, causing a rotation of the ethmoid bone
When the SBS is in flexion, the ethmoid will
move in the same direction as the occiput
When the SBS is in flexion, the vomer will
move in the same direction as the sphenoid
During SBS flexion, the palatines
will move in external rotation primarily
During SBS flexion the interpalatine suture will
move inferiorly with vomer and maxillae
Somatic dysfunctions at the SBS
-simplest is the strain patterns
Lateral strain
-named for the position of the base of the sphenoid (basisphenoid)
SBS lateral strain azes
- superior-inferior
- 2 vertical axes
SBS lateral strain direction
- same for both bones
- label for the motion of the basisphenoid
SBS vertical strain
- named for the direction of the basisphenoid
- can have a superior or an inferior vertical strain pattern
Superior vertical strain
-bones rotate anterior around involved axes
Inferior vertical strain
-Bones rotate posterior around involved axes
Vertical strain axes
-2 transverse axes
Vertical strain direction
-same direction
SBS torsion
- named for position of the greater wing of the sphenoid during cranial flexion
- the greater wing that moves cephalad during cranial flexion
- right or left torsion
- 1 AP axis
SBS Sidebending rotation
- biplanar dysfunction
- combined side bending and rotation
- named for the side of the convexity developed in the cranium
- 1 AP axis, 2 vertical axis
- “vrack the egg and pour it”
SBS and Sacral motion
- SBS flexion pulls up on the dural sleeve of the cord
- sacrum moves posteriorly (counternutation)
- SBS extension–sacral nutation
Midline bones rotate about
a transverse axis in the sagittal plane
Cranial flexion
- SBS superior
- Occiput inferior/posterior
- ethmoid mirrors occiput motion/opposite sphenoid
- vomer same direction as sphenoid
- palatine: internal rotation
- interpalatine suture: superior with vomer and maxillae
Sacrum moves about a
transverse axis through the 2nd sacral segment in the sagittal plane
In cranial flexion, sacral base
posterior
counternutation
In cranial extension sacral base
anterior
nutation
SBS flexion pulls
up on dural sleeve of cord, thus sacral base moves posterior (counternutation)–transverse axis/sagittal plane just like occiput
Ethmoid motion influenced by
-sphenoid and falx cerebri
Ethmoid motion in SBS flexion
- rotates about transverse axis through middle of bone, in same direction as occiput
- motion is in sagittal plane
- lateral masses move as paired bones into external rotation during cranial flexion and internal rotation during cranial extension
Lateral strain pattern
- sphenoid and occiput rotate about vertical axes in the same direction
- side to side (lateral) shearing of the SBS
- usually caused by trauma lateral to one side of anterior cranium or the opposite of the posterior cranium
- head looks like parallelogram
- side to side findings are asymmetric?
Right lateral strain
-basi-sphenoid shears to right around vertical axis, occiput and sphenoid both rotate left around their vertical axis
vertical strain pattern
- flexion at the sphenoid is accompanied by extension at the occiput (superior strain) or vice versa for inferior strain
- rotation on transverse axis with motion in sagittal planes
- side-to side findings symmetrical
Inferior vertical strain
- sphenoid extended, occiput flexed
- thumbs point to doc
SBS torsion
- rotation of SBS around an AP axis
- axis runs from nasion to opisthion, motion in coronal plane
- sphenoid and occiput rotation in opposite directions
- torsion named for the side of the more cephalad greater wing of sphenoid
Left torsion
- abnormal flexion/extension while sphenoid twists R (freater wing elevates on L), occiput twists L at SBS, L basisphenoid
- hands twist on each other with left thumb pointing to doc and right thumb moving away
SBS torsion: changes in other bones
- temporal and parietal bones: relative external rotation on the side of the torsion
- mandible: shifted toward the side of the torsion
orbit: smaller on side of torsion - falx cerebri: anterior end rotates with sphenoid, posterior end rotates with occiput
- tentorium cerebelli: sidebent same direction as occiput rotates
- spinal dura: inferior on side of low occiput
SBS side bendng
- occurs by rotation around 2 vertical axes in the transverse plane
- through the center of the body of the sphenoid and through the center of the foramen magnum on occiput
- the sphenoid and occiput rotate in the opposite directions on these axes causing side bending at the SBS
SBS rotation
- occurs on the same AP axis as torsion; however, the sphenoid and occiput rotate (coronal plane) in the same direction
- rotation occurs toward the side of convexity, which is relatively inferior/caudad
SBS side bending and rotate dysfunctions are named for
convexity (wider side) of side bending motion
Right SBS rotation
- sphenoid SB L, rotated R and occiput SB R rotated R
- right hand over down and spreads out with left hand moving up and in
SBS side bending and rotation changes in other structures
- temporal and parietal bones externally rotated on convex
- frontal bone and orbit anterior on convex side
- mandible shifted to convex side
- falx cerebri: SB following convexity of SB of SBS
- tentorium cerebelli: follows occipital motion
- spinal dura: inferior on convexity
SBS compression
- result of pressure or trauma to front of head or face, to back of head or entire periphery (i.e., infant cranium in birth)
- manifests as a restriction (mile to severe) of all motions at the SBS
- with severe compression, cranium feels rigid
SBS flexion dysfunction
- extension restricted
- increased in transverse dimension
- forehead wide and sloping
- eyes prominent
- paired bones externally rotated
- ears protruding
SBS extension dysfunction
- flexion restricted
- increased in longitudinal dimension
- vertical forehead
- eyes receded
- paired bones internally rotated
- ears close to head
SBS torsion dysfunction: side of high sphenoid wing
-frontal lateral angle anterior
-orbit wide
-frontozygomatic angle increased
-eyeball protruded
-zygomatic orbital rim everted and externally rotated
symphysis menti to this side
-mastoid tip posteromedial
SBS torsion dysfunction: side of low sphenoid wing
-posterior frontal lateral angle
-narrow orbit
frontozygomatic angle lessened
-eyeball retruded
-zygomatic orbital rim inverted and internally rotated
-mastoid tip anterolateral
-ear close to head
SBS rotation/Side-bending dysfunction: convexity
- lateral frontal angle posterior
- orbit narrow
- frontozygomatic angle lessened
- eyeball retruded
- zygomatic orbital rim prominent
- symphysis menti to this side
- mastoid tip posteromedial
- mastoid portion anterolateral
- ear protruding
SBS rotation/side bending dysfunction: concavity
- lateral frontal angle anterior
- orbit wide
- frontozygomatic angle increased
- eyeball protruded
- zygomatic orbital rim flat
- symphysis menti away from this side
- mastoid tip anterolateral
- mastoid portion posteromedial
- ear close to head
