Cervical Spine Flashcards
More muscles are associated with what region of the spine compared to the others?
Cervical
What is the most mobile region of the vertebral column?
Cervical spine
What is the overall job of the cervical spine?
Maintain head posture while allowing a lot of mobility
Which spinal curve is the least distinct?
Cervical
Which spinal curves are considered secondary/compensatory curves?
Cervical and lumbar
What is the most complex region of the axial skeleton?
Occiput-Atlas-Axis
Where in the spine do we see no intervertebral disc at the site of articulation?
Atlanto-occipital and atlanto-axial articulations
What are important upper cervical muscles?
Rectus capitus posterior major and minor
Rectus capitus lateralis and anterior
Superior and inferior obliques
What are important stabilizing ligaments of the upper cervical region?
Transverse ligament of atlas Alar PLL Anterior and posterior atlanto-occipital membrane Ligamentum nuchae Apical ligament
What is unique about the superior articular process of atlas?
1 called lateral masses
2 peanut-like shaped facets
3 concave and medial
How does the shape of the atlas lateral masses affect its rotational ability?
Little rotation possible
The shape of the articulation at occiput-atlas favors what axis?
θX
Even though flexion-extension occurs in a rotational manner at occiput-C1, how do we evaluate for restriction with palpation?
Occipital “glide”
What is the reference point for evaluation of flexion-extension at occiput-C1?
Occipital condyles
Instead of saying the occipital condyles translated P-A, what is the proper motion?
Rotates posterior and superior (PS flexion, + θX)
Instead of saying the occipital condyles translated A-P, what is the proper motion?
Rotates anterior and superior (AS extension, - θX)
What limits flexion at the occiput-C1 region?
Posterior neck muscular tension
What limits extension at the occiput-C1 region? **
Suboccipital muscle compression against the occiput
What is the average range of flexion-extension seen at occiput-C1?
14-35 degrees
What limits axial rotation at occiput-C1?
1 Anterior and posterior walls of C1 sockets
2Joint capsule tension
3 Alar ligament tension ***
What is the range of minimal axial rotation exhibited at the occiput-C1 region?
4-8 degrees to each side
In what region of the cervical spine has lateral flexion only been induced in cadavers but not seen physiologically in a live human in NORMAL motion?
Occiput-atlas
When induced in cadavers, what is the range of lateral flexion seen at occiput-C1?
4-11 degrees
What attachment limits Z axis rotation at occiput-atlas?
Alar ligament
What is unique about the articulation of facets at atlas-axis?
Biconvex articulation due to articular cartilage formation
What is the combined degree of X axis rotation seen at C1-C2?
20 degrees
How does increased curvature of the dens on C2 affect θX?
Increases amount of θX
What is the term for a path that identifies where one body will rotate relative to another body at a given instant in time?
IAR: Instant axis of rotation
What are the roles of C2?
1 transmit axial load of head to cervical spine
2 permit LOTS of Y axis rotation
What restrains the axial rotation found at C1-C2?
Alar ligaments
If a patient presents with almost ZERO motion in his/her neck, what area of the cervical spine is usually to blame?
C1-C2
If a patient presents with minimal motion in his/her neck, what area of the cervical spine is usually to blame?
Lower cervicals
What region of the cervical spine exhibits 43 degrees (plus or minus 5) of axial rotation making up over 50% of the rotation of the entire neck?
C1-C2
What is the order in which axial rotation occurs in the cervical spine?
1st 45% occurs at C1-C2, then occiput region, the lower cervicals
When visualizing on X-ray, what appearance of a C1 lateral mass indicates rotational anteriority on that side?
Bigger lateral mass
What fills the spaces between the cartilages where the surfaces of the articular cartilages diverge both anteriorly and posteriorly?
Intraarticular meniscoids
What is the function of intraarticular meniscoids?
Keep a film of synovial fluid applied to the surfaces of articular cartilages that are not in contact with one another
What motion displaces the intraarticular meniscoids?
Y axis rotation
What other motion minimally is coupled with θY at C1-C2?
Y translation
When C1-C2 goes from neutral to a rotated state, in which direction do we seen Y translation?
- Y translation
When C1-C2 goes from a rotated to neutral state, in which direction do we seen Y translation?
+ Y translation
What is lateral bending limited to about 5 degrees at the C1-C2 articulation?
Bony anatomy and alar ligaments
Why is only little Z axis translation seen at C1-C2?
Tight articulation of C1 ring around dens due to ligaments
According to Panjabi and White, how much X axis translation is seen at C1-C2?
None (there is only “apparent” translation)
What motion at C1-C2 is considered controversial?
X axis translation
During lateral flexion at C1-C2, to which direction does the spinous process of C2 rotate?
Toward the convexity of the lateral bend AKA OPPOSITE side
When laterally bending the cervical spine, to which direction does the spinous process rotate?
Contralateral side
What two motions are coupled in the cervical spine?
1 Axial rotation about a longitudinal axis
2 Lateral rotation about a sagittal axis
+ θX in the cervical spine is coupled with what other motion?
+ Z translation
- θX in the cervical spine is coupled with what other motion?
- Z translation
+ θZ in the cervical spine is coupled with what other motion?
- θY
- θZ in the cervical spine is coupled with what other motion?
+ θY
In what region of the cervical spine do we see less rotation with lateral bending?
Lower cervicals
What is the primary motion at occiput-C1? ***
Flexion-extension
What is the primary motion at C1-C2? ***
Axial rotation
What is the primary motion of the lower cervicals? ***
Flexion-extension
Where in the cervical spine do we see the steepest arch of a vertebra when moving from flexion to extension?
C6 and C7
Where in the cervical spine are the arches flat when moving from flexion to extension?
C2
What causes the acuity of the arcs to decrease when moving from flexion to extension in the cervical spine?
Degeneration
In what part of the cervical spine does more translation occur with flexion/extension?
Upper cervical spine
What motion is limited by the anterior longitudinal ligament?
Negative θX (extension)
What motion is limited by the posterior longitudinal ligament?
Positive θX (flexion)
What motion is limited by the ligamentum flavum?
Slows the last few degrees of flexion (positive θX)
What motion is limited by the interspinous ligament?
Positive θX (flexion)
What motion is limited by the ligamentum nuchae?
Positive θX (flexion)
What motion is limited by the inter transverse ligament?
Contralateral lateral flexion (θZ)
In which direction does the transverse diameter of the rectangular vertebral body of the cervical spine increase?
Superior to inferior
What is the shape of the superior and inferior surfaces of the cervical vertebral bodies?
Sellar or saddle-shaped
What motion is reduced and what motion is promoted in the cervical spine?
Reduced - X axis translation
Promoted - X axis rotation
Uncinate processes serve what purposes when it comes to motion?
1 limit pure lateral flexion
2 guides to couple lateral flexion with axial rotation
Degeneration of uncovertebral joints results in what?
Bony outgrowth with potential for damage
Bony outgrowth due to uncovertebral joint degeneration could impinge what adjacent anatomy?
1 vertebral artery
2 cervical spinal nerves
Which annulus of the intervertebral disc in the cervical region is thick and strong?
Anterior
Which annulus of the intervertebral disc is minimal if even present due to uncinate processes?
Lateral
Which annulus of the cervical intervertebral disc is only a concentrated central bunch of fibers?
Posterior
What is the average degree of facet orientation in the cervical spine? ***
45 degrees
What is the superior facet orientation in the cervical spine?
Posterior, superior, medial (BUM)
What is the inferior facet orientation in the cervical spine?
Anterior, inferior, lateral (FOLD)
What is the “trick” for remembering the inferior facet orientations of the spine?
AIL (cervicals)
AIM (thoracics)
AIL (lumbars)
What effect does age have on the zygapophyseal joint?
1 thinning of articular cartilage
2 thickening of subarticular bone
3 osteophyte formation
What is proprioception?
Sensory perception of movement or position within the body
What 3 things in the cervical spine have proprioceptive function?
1 IVD
2 Facet joints
3 Cervical musculature
What is the role of facet mechanoreceptors?
Responsive to extreme joint motions
What do muscle spindles detect?
Changes in the length of a muscle
Where are muscle spindles located?
Belly of a muscle
Which specific spinal muscles contain a high density of muscle spindles?
Suboccipital muscles
What is the primary reason for the high content of muscle spindles in the neck muscles?
Proper head-eye coordination
What is the gate theory?
The idea that proprioceptive input flowing into the dorsal hour serves to disallow or modulate nociceptive input into the CNS therefore impacting pain levels
What occurs when there is a change in the stimulus-response profile of dorsal horn neurons so that they respond to mechanoreceptive afferents as if they were nociceptors?
Sensitization (hypersensitivity) due to CNS facilitation
How can chiropractic adjustments help with hypersensitivity to pain?
Decrease the hyperexcitable central state
What muscular changes are seen on an MRI of the suboccipital muscles of those with chronic neck pain compared to healthy individuals?
Atrophy
Fatty infiltration/degeneration
When does the cervical curve begin to develop?
Prior to birth
What is the purpose of the cervical curve being a lordosis?
Absorbs spinal loads
What radius of a cervical lordotic curve is considered normal?
17 cm
What term is used when a normal cervical curve has diminished?
Hypolordotic (military neck)
Which cervical vertebra is considered the keystone vertebra in forming the cervical curve?
C5
Why do some suggest breaking the cervical spine into two curvatures?
Occiput to axis is concave anteriorly (kyphotic)
C2 to C7 is the classical lordosis
What should the normal angle of the cervical lordosis be when measured between lines drawn through C1 and C7? **
30-45 degrees
What type of deviation from the normal cervical curve is most common?
Hypolordosis
What types of cervical curve changes are associated with tension headaches?
Straightened or reversed cervical curves
How did Brieg have success in improving neurological disorders by focusing on the cervical spine?
Inducing a lordosis
What is the primary load on the cervical spine?
Compression
Compressive loads in the cervical spine increase during what motion?
Flexion-extension
What allows the cervical spine to bear large compressive loads? **
Appropriate lordotic curve (compressive follower load path)
The increased stability of the cervical spine that comes from the added compression is due to what?
Muscular action (follower load, NOT vertical load)