Chapter 9 Flashcards
How often is atlas misalignment compensatory?
82% of the time
Why is atlas subluxation different?
There is no disc
Why is nerve pressure different with atlas subluxations?
There is no disc and pressure comes from the capsular ligament
Describe the act of subluxation at atlas? Difference from other segments?
Must be an osseous misalignment, damaging interarticular fibers, leading to edema that causes the capsular ligament to swell putting pressure on the nerve.
The capsular ligament is being effected instead of the disc
For atlas/occiput where will nerve pressure be found?
Atlas- nerve pressure will be between atlas and axis
Occiput- nerve pressure will be between occiput and atlas
2 ways to improve relationship between atlas and occiput?
Correct atlas when subluxated to decrease the compensatory misalignment between atlas and occiput, and “jab like” thrusts setting atlas into motion may also decrease compensatory misalignment between atlas and occiput
What subluxates more, atlas or occiput?
Atlas far more
Explain foundation principle?
The foundation principle basically explains that you are setting the vertebra above to the vertebra below not the vertebra below the vertebra above because you get support from the vertebra below not the vertebra above
What are exceptions to the foundation principle? Why?
Base posterior and coccyx
BP- Because you can’t set an anterior L5 back to sacrum and because there is no weight bearing structure under sacrum so you have to set sacrum under L5
Coccyx- Because coccyx is most inferior so it has to be set to the sacral apex
Where will motion be diminished?
It will be greatly diminished
When both sides are inflamed, how do you differentiate?
One side will always be more inflamed and protruded than the other
What nerve fibers are compressed with an atlas subluxation?
Cervical spinal cord, 1st and 2nd cervical spinal nerves (C1, C2), superior cervical ganglion, vagus, hypoglossal, spinal accessory
How does atlas compress nerve fibers?
Protrusion of the articular capsules compress nerve fibers
How does atlas compress vagus?
Anterior rotation of the atlas transverse puts pressure on the carotid sheath and compresses the enclosed vagus
How does atlas compress super cervical ganglion?
When atlas transverse rotates anterior it can compress SCG
How can C2 spinal nerve not be compressed?
When atlas rotation is the major component of the subluxation it is possible for the 2nd spinal nerve to be unaffected
What are the functions of the nerves?
Somatic afferent, somatic efferent, visceral afferent, SNS and PSNS
How could atlas be responsible for subluxation(s) below?
Subluxation of atlas could cause cord pressure affecting the Gamma Efferent motor fibers causing paravertebral muscle contraction through stretch reflex mechanism. You’d have to correct atlas to clear the cord pressure that would allow those muscles to relax so you can correct the other subluxations
Through the parasympathetics how can atlas “cause” nerve pressure below?
PSNS pressure can cause a hypersecretion of various endocrine glands such as the thyroid, adrenals, sex hormones and others. When this happens the synovial membrane and bursae become inflamed and swollen. This may cause the discs to be edematous and protruded causing compression of adjacent spinal nerves
When axis/atlas plane lines are not parallel what can you infer?
Atlas has gone anterior
What side will nerve pressure be on with an atlas subluxation?
The side of atlas laterality
What are 3 ways to determine atlas rotation?
Measuring lateral masses, measuring the radiolucency on the medial borders of the lateral masses, and the atlas and occipital condyle lines converge on the side of anterior rotation
How will occiput compensate for an anatomically deficient leg?
The condyle will be elevated on the side of an anatomically short leg
Why can’t you use para-odontoid space to determine laterality?
Because atlas laterality is obscured by atlas rotation
What has to be ascertained before the segmental level can be determined?
-
When will atlas be fixated in subluxation but not have enough swelling to compress C2 spinal nerve?
-
Short leg on the left will do what to occipital condyle on left?
Raise the left condyle
How does atlas/occciput misalignment effect spinal canal?
AS- makes canal smaller
PS- makes canal larger
When occiput/atlas are aligned what is the angle formed on the lateral between the lines? With an AS or PS occiput?
An angle of approx 5 degrees
AS occiput= angle will be decreased
PS occiput= angle will be increased
When occiput is subluxated what do you expect to find with atlas and axis on the A-P? Why? What about rotation of occiput?
The atlas and axis lines would be parallel because the principle motion is rotation around the odontoid not laterality.
The rotation of occiput would be opposite of atlas due to compensation
