Cranial strains

Question 1

Physiologic motion of midline bones

Answer 1

Midline bones: spehnoid, occiput, ethmoid (medial plate), vomer, and sacrum

Flexion and extension phases

Question 2

Physiologic motion of paired bones

Answer 2

Paired bones: temporals, parietals, frontals, ethmoid (lateral mass), nasals, lacrimals, maxillae, palatines, zygomae, inferior conchae, and mandible

External and internal rotation phases

Question 3

Physiologic motion

Answer 3

Flexion occurs with external rotation

Extension occurs with internal rotation

Question 4

Reciprocal tension membrane

Answer 4

• 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

Creates a tensegrity model that guides motion

Question 5

Sphenobasilar synchrondrosis (SBS)

Answer 5

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 through contact with:

• The greater wings of the sphenoid
• The lateral angles of the occiput

Question 6

Vault hold

Answer 6

Hands are in such a position to be able to palpate and observe motion of the SBS through contact with the sphenoid and occiput

• Index fingers on greater wings of sphenoid
• Pinky fingers on the lateral angles of the occiput
  (ear is in between middle and ring finger)

Enables the operator to feel the dysfunction in order to initiate treatment.
Treatment also begins with this hold

Question 7

Cranial strains

Answer 7

1. Flexion/extension: inherent motion of SBS but can still get SD
2. Torsion: right or left
3. Sidebending rotation: right or left
4. Vertical strain: superior or inferior
5. Lateral strain: right or left
6. SBS compression

Question 8

Physiologic strains

Answer 8

Physiologic strains are those normal compensatory patterns that happen in response to other motions of the body.

These are normal EXCEPT when the SBS gets stuck there. Causes SD.

• Flexion/extension
• Torsions
• Sidebending rotation

Question 9

Flexion

Answer 9

Motion is rotational around 2 transverse axes:

• At level of foramen magnum
• Body of sphenoid

Motion occurs at SBS:

• Basioocciput and basisphenoid move cephalad
• Occipital squama and wings of spenoid move caudally

Question 10

Extension

Answer 10

Motion is rotational around 2 transverse axes:

• At level of foramen magnum
• Body of sphenoid

Motion occurs at SBS:

• Basiocciput and basisphenoid move caudad
• Occiptal squama and wings of sphenoid move cephalad

Question 11

Torsion

Answer 11

Sphenoid and occiput rotate in opposite directions around an AP axis

Named by the superior greater wing of the sphenoid… which is mirroring the motion of the basisphenoid.
EX: right greater wing superior and left occipital angle superior = right torsion

In the vault hold- one greater wing superior to the other AND the opposite occipital angle more superior than the others

Question 12

Sidebending rotation

Answer 12

Sphenoid and occiput rotate around 2 sets of axes:

• To sidebend: opposite directions around parallel vertical axes
• To rotate: in the same direction around AP axis

Altogether this gives the sense of convexity and inferior motion on one side.
- Named for the side of the convexity (the side that gets fat) and inferior motion

Shadow hands
R SBS sidebending rotation:
- Right index and pinky fingers move inferiorly and spread apart slightly in comparison to the left

Question 13

Non-physiologic strains

Answer 13

Strains that are never normal at the SBS. Usually happen in response to trauma

• Lateral strains/shears
• Vertical strains/shears
• SBS compression

Question 14

Lateral strains

Answer 14

Sphenoid and occiput rotate in the same direction about parallel vertical axes resulting in a lateral shearing force at the SBS.

Named by the direction the basisphenoid moves.
- Basisphenoid and greater wings of ethmoid move in opposite directions.

In the vault hold, your hands will form a parallelogram.
- Index fingers will shift one direction, while the pink fingers shift in the opposite

Right lateral strain:

• Both index fingers shift left
• Both pinky fingers shift right

Question 15

Vertical strains

Answer 15

Sphenoid and occiput rotate in the same direction on parallel transverse axes (as in flexion and extension)

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, the index fingers will move in the opposite direction of the basisphenoid

• Superior vertical strain: wings down, base up
• Inferior vertical strain, wings up, base down

Question 16

Shadow hands for lateral strains

Answer 16

Index fingers will move in the OPPOSITE direction of the basisphenoid

Index fingers move right, basi-sphenoid moves left = LEFT lateral strain

Index fingers go left, basisphenoid moves right= RIGHT lateral strain

Question 17

Shadow hands for vertical strains

Answer 17

Index fingers will move in the OPPOSITE direction of the basisphenoid

Index fingers go inferiorly, basisphenoid moves superiorly = superior vertical strain

Question 18

SBS compression

Answer 18

Approximation of the sphenoid and occipital bases as they compress together along the AP axis

In vault hold:

• Fingers of both hands approximate
• More commonly, bc this severly 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

Question 19

Causes of cranial SD

Answer 19

• Birth trauma
• Intrauterine position
• Head trauma
• Falls on the buttock
• Surgical trauma
• SD from other areas of the body
• Viscero-somatic reflexes

Question 20

Practice: R index and pinky fingers are superior to the L, while the index and pinky fingers on the L spread apart and move inferiorly.
Diagnosis?

Answer 20

Left sidebending rotation

Question 21

Practice: index fingers shift L, pinky fingers shifted right

Diagnosis?

Answer 21

Right lateral shear

Question 22

Practice: both index fingers move inferiorly, both pinky fingers move superiorly

Answer 22

Superior vertical strain

Question 23

Practice: 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

Answer 23

SBS compression

Question 24

Perspective

Answer 24

When figuring out the cranial strain based on the vault hold, remember where your landmarks are in relationship to anatomical position of the patient.

Question 25

Potential traumatic forces involved with superior vertical strain

Answer 25

• Caudal force applied centrally over the anterior- superior frontal bone.
• Force to the superior occiput (near lambda) and directed from superior/posterior to anterior

Question 26

Potential traumatic forces involved with inferior vertical strain

Answer 26

• Caudal force transmited 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 (landing on the buttocks with a force transmitted up the spine)
• A caudal force transmitted over the bilateral posterior-superior parietal bones or along ht eposterior sagittal suture

Question 27

Potential Traumatic Forces Involved in SBS compression

Answer 27

Force directed along the AP axis leading to longitudinal compression of the SBS. May originate at nasion or at opisthion

Question 28

Potential Traumatic Forces involved in lateral strains

Answer 28

• Lateral to medial directed force applied over the greater wing of the sphenoid pushing the greater wings to the left or right (a medially directed force to the left greater wings will drive the basisphenoid to the opposite direction)
• Lateral to medial directed force applied over the occiput pushing the posterior aspect of the occiput left or right