cranial strain patterns

Question 1

torsion motion

Answer 1

sphenoid and occiput rotate in opposite directions around an A-P axis

Question 2

how is torsion named?

Answer 2

named by the superior greater wing of the sphenoid

Question 3

vault hold in L torsion

Answer 3

1. L index finger moves superior (towards you) and 5th digits moves inferiorly
2. R index moves inferiorly and 5th digit moves superiorly

Question 4

sidebending rotation motion

Answer 4

1. sphenoid and occiput rotate in opposite directions around parallel vertical axes to side bend
2. sphenoid and occiput rotates around A-P axis in same direction so that on the side of the SBS convexity, the cranium moves inferiorly

Question 5

how is sidebending rotation named?

Answer 5

named by the side of the SBS convexity and the side that moves inferiorly

Question 6

vault hold in sidebending rotation

Answer 6

fingers of one hand spread apart and move inferiorly (side of the strain is named for), while the fingers of the other hand comes together and move superiorly

Question 7

vertical strains motion

Answer 7

1. sphenoid and occiput rotatein the same direction about parallel transverse axes (as in flexion/extension) which results in a shearing force at the SBS
2. one bone in flexion while other is in extension

Question 8

how are vertical strains named?

Answer 8

named by the direction of the base of the sphenoid (basisphenoid)

Question 9

vault hold for vertical strains

Answer 9

a superior vertical strain the hands appear to rotate in the same direction such that index fingers of both hands move inferiorly (the sphenoid base is moving superiorly), while the 5th digits of both hands move superiorly (occipital base is moving inferiorly).

Question 10

lateral strains motion

Answer 10

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

Question 11

how are lateral strains named?

Answer 11

named by the direction the basisphenoid moves.

Question 12

vault hold for lateral strains

Answer 12

your hands form a parallelogram. In a left lateral strain, your index fingers shift to the right (sphenoid base turns to the left), while your 5th digits shift to the left (occipital base turns to the right). The reverse is true of a right lateral strain.

Question 13

SBS compression motion

Answer 13

Approximation of the sphenoid and occipital bases as they compress together along the A-P axis.

Question 14

vault hold for SBS compression

Answer 14

fingers of both hands approximate. The distance between the sphenoid wings and the occipital lateral angles on both sides is reduced. Because this severely limits the resiliency of the SBS, flexion and extension are limited, and often these heads will feel hard and generally limited in movement of any kind (often associated with a decreased Primary Respiratory Rate).

Question 15

potential traumatic forces causing superior vertical strain

Answer 15

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

Question 16

potential traumatic forces causing inferior vertical strain

Answer 16

• 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.

Question 17

potential traumatic forces causing SBS compression

Answer 17

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

Question 18

potential traumatic forces causing lateral strains

Answer 18

• 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.

Question 19

potential traumatic forces causing external rotations of the temporal bones

Answer 19

• 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.