Cranial Strains (Ferrill) Flashcards
Physiologic Motion of the head
Midline bones
* Sphenoid, * occiput, ethmoid (median plate), vomer & sacrum
Flexion & extension phases
Paired bones
* Temporals, parietals, frontals, ethmoid (lateral mass), nasals, lacrimals, maxillae, palatines, zygomae, inferior conchae & mandible
External & internal rotation phases
Physiologically, flexion occurs with external rotation (“flexternal rotation”)
Extension occurs with internal rotation
Reciprocal tension membrane
Falx cerebri & cerebelli
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
Creates a tensegrity model that guides motion
SBS
All cranial motion at the SBS is named for the motion of the basi-sphenoid on the basi-occiput
We are observing the motion of the basi-sphenoid on the basi-occiput though contact with
the greater wings of the sphenoid
The lateral angles of the occiput
Vault Hold
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
Perspective matters
This is important to getting the concepts of motion, and the diagnosis, correct
Try to think about where the SBS is in relationship to your hands
- Where is the top of the patient’s head? Where are the feet?
In many animations today, the top of the head is at 12 o’clock
When you patient is on the table, and while you are doing shadow hands, the top of the head is coming toward you
Cranial Strains
Flexion/Extension
- Inherent motion of SBS
- Can still get somatic dysfunction
Torsion
- Right or left
Sidebending rotation
- Right or left
Vertical strain
- Superior or inferior
Lateral strain
- Right or left
SBS compression
Physiologic Strains
Physiologic strains are those normal compensatory patterns that happen in response to other motions in the body.
These are normal EXCEPT when the SBS gets stuck there. Then you have somatic dysfunction.
Flexion/ Extension
Torsions
Sidebending rotation
Flexion and extension
Normal physiological motion of the SBS
The sphenoid and occiput rotate around
parallel transverse axes
in opposite directions
Flexion
Ernie
Motion is rotational around 2 transverse axes
- At level of foramen magnum
- Body of sphenoid
Motion occurs at SBS
- Basiocciput & basisphenoid move cephalad while occipital squama & wings of sphenoid move caudally
Extension
Bert
Motion is rotational around 2 transverse axes
- At level of foramen magnum
- Body of sphenoid
Motion occurs at SBS
Basiocciput & basisphenoid move caudad while occipital squama & wings of sphenoid move cephalad
Shadow hands flexion
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
Shadow hands extension
In the vault hold:
Index fingers
- Move superiorly and approximate slightly
Pinky’s
- Move superiorly and approximate slightly
Torsion
Sphenoid and occiput rotate in
opposite directions
around an A-P axis.
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
Named for the superior greater wing
i.e. right greater wing superior (and left occipital angle superior) = right torsion
Torsion Shadow hands
Right SBS torsion
Right index finger moves superiorly in comparison to the left
Left pinky moves superiorly in comparison to the right
Left SBS torsion
Left index finger moves superiorly in comparison to the right
Right pinky moves superiorly in comparison to the left
Sidebending Rotation
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 and inferior motion on one side
Named for the side of the convexity and inferior motion
Non-physiologic strains
These are strains that are never normal at the SBS
They usually happen in response to trauma
- Lateral strains (sometimes called lateral shears)
- Vertical strains (sometimes called vertical shears)
- SBS compression
Lateral Strains
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 by the direction the basisphenoid moves.
Lateral Strains- in vault hold
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 left
- Both pinky fingers shift right
lateral strains shadow hands
Left lateral shear
Both index fingers shift right
Both pinky fingers shift left
Right lateral strain
Both index fingers shift left
Both pinky fingers shift right
Vertical Strains
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
vertical strains- vault hold
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”
vertical strains shadow hands
Superior vertical strain
Both index fingers shift inferiorly (as the base moves superiorly)
Both pinky fingers shift superiorly
Inferior vertical strain
Both index fingers shift superiorly (as the base moves inferiorly)
Both pinky fingers shift inferiorly
The key to the shears
The index fingers will move in the OPPOSITE direction of the basisphenoid
Lateral strains:
Index fingers moves right, basi-sphenoid moves left = LEFT lateral strain
Index fingers go left, basisphenoid moves right = RIGHT lateral strain
Vertical strains:
Index fingers go inferiorly, basisphenoid moves superiorly = SUPERIOR vertical strain
Index fingers go superiorly, basisphenoid moves inferiorly = INFERIOR vertical strain
SBS compression
Approximation of the sphenoid and occipital bases as they compress together along the A-P axis.
SBS compression- vault hold
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
SBS compression 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
Causes of cranial SD
Can be caused by: Birth trauma Intrauterine position Head trauma Falls on the buttock Surgical trauma Somatic dysfunction from other areas of the body Viscero-somatic Reflexes other
potential traumatic forces involved in superior vertical strain
- caudal force applied centrally over the anterior-superior frontal bone
- superior force to the inferior occiput, driving the basiocciput inferiorly
potential traumatic forces involved in inferior vertical strain
- caudal force transmitted to the basisphenoid such as a caudal force transmitted from bregma
- a cephalad force transmitted to the condylar parts such as a fall on the base of the spine (i.e. 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
potential traumatic forces involved in SBS compression
- force directed along hte AP axis leading to longitudinal compression of the SBS. may originate at nasion or at opisthion
potential traumatic forces involved in lateral strains
Lateral to medial directed force applied over the greater wing of the sphenoid pushing the greater wings to the left or right. (ie a medially directed force to the left greater wings will drive the basisphenoid in the OPPOSITE direction)
-Lateral to medial directed force applied over the occiput pushing the posterior aspect of the occiput left or right.
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.
In the vault hold, your right index and pinky fingers are superior to the left, while the index and pinky fingers on the left spread apart and move inferiorly. Diagnosis?
left sidebending and rotation
In the vault hold, your index fingers have shifted to the left, your pinky fingers have shifted to the right. Diagnosis?
right lateral shear
A patient comes to you complaining of headache after a box fell on the top of his head, close to the forehead. Osteopathic evaluation reveals both index fingers move inferiorly, both pinky fingers move superiorly. What is the SBS diagnosis?
Superior vertical strain
A patient comes in for evaluation after hitting her head on the ice while playing hockey. Osteopathic evaluation reveals minimal motion at the SBS. What is your cranial diagnosis?
SBS compression
