Cranial Strains (4-8 Ferril) Flashcards
what are the three things you need to know about strains
what motion occurs at the SBS
define the axis/axes of motion involved
physiologic or pathologic motion
what are the 6 cranial strains
flexion/extension- inherent motion of SBS (can still get SD) torsion sidebending rotation vertical strains lateral strains SBS compression
what are the two midline bones we care about and what is their motion?
sphenoid and occiput
flexion and extension
what are the paired bones?
main motion?
Temporals, parietals, frontals, ethmoid (lateral mass), nasals, lacrimals, maxillae, palatines, zygomae, inferior conchae & mandible
external and internal rotation
physiologically, flexion of the cranium occurs with what other motion?
external rotation
“flexternal rotation”
physiologically, extension of the cranium occurs with what other motion?
extension
what is the reciprocal tension membrane
creates a tensegrity model that guides the motion of cranial bones b/c this membrane acts as a guide wire
falx cerebri
tentorium cerebelli
formed by dural reflections
Dura is contiguous with periosteum of skull, and extends throughout the spinal column creating link to sacrum and throughout the body
what is the vault hold
which fingers are on which bones
Hands are in such a position to be able to palpate and observe motion of the SBS though contact with the sphenoid and occiput
Index fingers on the greater wings of the sphenoid
Pinky fingers on the lateral angles of the occiput
Enables the operator to feel the dysfunction in order to initiate treatment
Treatment also begins with this hold
all cranial motion at the SBS is named for motion of the….
motion of the basi-sphenoid on the basi-occiput
what are the physiological strains
flexion/extension
torsions
sidebending rotation
These are normal except when the SBS gets stuck there, then you get SD
flexion and extension occur about which axis and in which directions do the sphenoid and occiput rotate?
occur about parallel transverse axis about the level of foramen magnum and body of sphenoid
sphenoid and occiput rotate around in opposite directions
what is the motion of the sphenoid and occiput during flexion?
basiocciput and basisphenoid move cephalad while occipital squama and wings of sphenoid move caudally (inferior)
landmarks move inferiorly on the patient and away from your fingers
what is the motion of sphenoid and occiput during extension and what do you feel in your fingers
your fingers will move superiorly and towards you on the patient and the base moves away from you.
basiocciput and basisphenoid move caudad (inferior) and the occipital squama and wings of sphenoid move cephalad
explain what the diagnosis of flexion feels like under your fingers
In the vault hold
Index fingers (on the greater wings of the sphenoid)
Move inferiorly and spread apart slightly
Pinky’s (on the occipital lateral angle)
Move inferiorly and spread apart slightly
explain what the diagnosis of extension feels like on your fingers
In the vault hold Index fingers Move superiorly and approximate slightly Pinky’s Move superiorly and approximate slightly
during torsion which directions do the sphenoid and occiput rotate and around what axis
opposite directions
around an A-P axis.
what is torsion SD named for
Named by the superior greater wing of the sphenoid
Which is mirroring the motion of the basi-sphenoid
In the vault hold
One greater wing superior to the other
AND
The opposite occipital angle more superior than the other
name the diagnosis:
Right greater wing superior and left occipital angle superior =
right SBS torsion
Right index finger moves superiorly in comparison to the left
Left pinky moves superiorly in comparison to the right
what do you feel if there is a left SBS torsion
Left index finger moves superiorly in comparison to the right
Right pinky moves superiorly in comparison to the left
what occurs with sidebending rotation
what is the axis of rotation
what does it feel like on the side of SD
what is it named for
Sphenoid and occiput rotate around two sets of axes
–To sidebend –> OPPOSITE directions around
parallel vertical axes
-To rotate–>
in the same direction
A-P axis
Altogether this gives the sense of convexity (fullness) and inferior motion on one side
Named for the side of the convexity and inferior motion
what occurs during right SBS sidebending and rotation
Right index and pinky fingers move inferiorly and spread slightly in comparison to the left
what occurs with left SBS and rotation
Left index and pinky fingers move inferiorly and spread slightly in comparison to the right
what are the NON physiological strains
never Normal at the SBS
usually happen in response to trauma
lateral strains (aka lateral shears) vertical strains (aka vertical shears) SBS Compression
what occurs in a lateral stain
sphenoid and occiput rotate in the same direction about parallel vertical axes
resulting in a lateral shearing force at the SBS
lateral strains are named for the direction the basosphenoid moves (so even though the wings of the sphenoid are moving to the left, the base of the sphenoid moved right)
what do you feel in the vault hold with a lateral strain
In the vault hold, your hands will form a parallelogram.
Index fingers will shift one direction, while the pinky fingers shift in the opposite
Right lateral strain:
Both index fingers shift right
Both pinky fingers shift left
what is a result in babies of a lateral strain
plagiocephaly - weird looking head
for a left lateral shear what happens with you fingers
both index fingers shift right
both pinky fingers shift left
for a right lateral shear what happens to your fingers
Both index fingers shift left
Both pinky fingers shift right
in a vertical strain, what direction do the sphenoid and occiput rotate and about what axis
what are vertical strains named for
Sphenoid and occiput rotate
in the same direction about
parallel transverse axes (as in flexion/extension)
which results in a shearing force at the SBS.
One bone is in flexion while the other is in extension.
Vertical strains are named by the direction of the basisphenoid
Superior or inferior
in the vault hold what will you feel for a vertical strain
In the vault hold the index fingers will move the OPPOSITE direction of the basisphenoid
Superior vertical strain is “wings down, base up”
Inferior vertical strain is “wings up, base down”
what occurs in a superior vertical strain on your fingers
Both index fingers shift inferiorly (as the base moves superiorly)
Both pinky fingers shift superiorly
what happens in an inferior strain to your fingers
Both index fingers shift superiorly (as the base moves inferiorly)
Both pinky fingers shift inferiorly
you put your fingers in the vault hold and you don’t feel any motion at the landmarks….. what is it.
SBS compression
Bowling ball head
fingers of both hands approximate
More commonly, because this severely limits the resiliency of the SBS, flexion and extension are limited
Often these heads will feel hard and generally limited in movement of any kind
what is the SBS compression
about what axis ?
what are your shadow hands doing for this SD
Approximation of the sphenoid and occipital bases as they compress together along the A-P axis.
shadow hands:
Index and pinky fingers on both sides will approximate indicating sphenoid compression onto the occiput
OR
No motion is felt at the SBS
what are some causes of cranial SD
Birth trauma Intrauterine position Head trauma Falls on the buttock** Surgical trauma Somatic dysfunction from other areas of the body Viscero-somatic Reflexes other
what are some potential traumatic forces involved in superior vertical strains
- Caudal (inferiorly directed) force applied centrally over the anterior-superior frontal bone.
- Force to the superior occiput (near lambda) & directed from superior/posterior to anterior.
what are some causes of an inferior vertical strain
Caudal force transmitted to the basisphenoid such as a caudal force transmitted from bregma.
- A cephelad force transmitted to the condylar parts such as a fall on the base of the spine (ie. landing on the buttocks with a force transmitted up the spine).***
- A caudal force transmitted over the bilateral posterior-superior parietal bones or along the posterior sagittal suture.
what are some potential traumatic forces involved in a SBS compression
Force directed along the AP axis leading to longitudinal compression of the SBS. May originate at nasion or at opisthion.
what are some potential causes of lateral strains
Lateral to medial directed force applied over the greater wing of the sphenoid pushing the greater wings to the left or right.
-Lateral to medially directed force applied over the occiput pushing the posterior aspect of the occiput left or right.
what are some potential traumatic forces involved in external rotations of the temporal bones
Force applied to the left mandible in a left to right direction yields a right externally rotated temporal bone rotation and a left internally rotated temporal bone rotation.
-Traction of one side of the mandible due to dental work yields internal rotation on the ipsilateral side as the traction and external rotation on the contralateral side of the traction forces.
