Cervical Spine Biomechanics Flashcards
What did Takala determine about neck pain in the population based on gender
Men: 16%
Women: 18%
What did Aryanpur determine about the percent of the population that will have neck pain
10%
What Dvorak determine was the percent of soft tissue injuries
87.5%
What percent of soft tissue injuries were due to MVA
53%
What percent of soft tissue injuries were due to falls and sports
45%
True or False:
You have to have to have radicular symptoms or referred symptoms with neck pain
False
How many cervical vertebrae are there
7
What are the atypical cervical vertebrae
1 and 2
What are the typical cervical vertebrae
3-6
What is C1
Cradle/Atlas
What is C2
Axis
What is C3
The root
What are C4-7
Column
What is C7
A transitional vertebrae
What is a transitional vertebrae
A vertebrae is starting to look like the next set of vertebrae
What is another name for C7
Vertebral Prominens
What i transegrity
Balance between mobility and stability
What are the size of cervical vertebrae bodies
Small
Why are cervical vertebrae bodies small
Wolffe’s Law… They don’t support a lot of weight
What are cervical vertebrae made for stability or mobility
Mobility
What is the neutral zone
The OA AA complex
How much more neutral is the OA AA complex than the lower cervical vertebrae
50%
True or False:
Cervical vertebrae have general laxity to capsule and ligaments
True
What is looser the upper cervical or lower cervical spine
Upper cervical spine
Where are the uncinate processes located
Posterolateral superior and inferior surfaces of vertebral bodies
What do the uncinate processes form
The uncovertebral joints
What is another name for the uncovertebral joints
Joints of VonLuschka
How are the transverse processes oriented in the cervical vertebrae
Anterolateral
True or False:
The transverse processes of the cervical vertebrae have lateral grooves
True
What do the lateral grooves predispose the vertebrae to
Fracture
What is the angle of the facet joints in the typical cervical spine
45 degrees
What are housed in the lateral grooves
Spinal nerves
What are the transverse processes of C1-4 usually called
Lateral masses
What do the bifid processes allow for
Greater surface area for attachment of soft tissue
What can cause vertebral artery compromise (3)
- Skeletal muscle and fascial bands near transverse foramen
- Osteophytes adjacent to C4/5 and C5/6 and C6/7
- Gliding motion at the AA articulation
What are osteophytes
Bone spurs
True or False:
C6 is a level of high mobility
True
How does flexion affect the vertebral artery
Nothing
How does extension affect the vertebral artery
Usually nothing
How does side bending affect the vertebral artery
Slight decrease in ipsilateral artery and normal contralateral artery
How does rotation affect the vertebral artey
Slight decrease in ipsilateral artery and slight superficial decrease in contralateral artery
How does extension and rotation affect the vertebral artey
Bilateral decrease
Where is the exclusion of the artery slightly worse during rotation and extension
Contralateral artery
How does flexion and rotation affect the vertebral artery
Bilateral decrease
True or False:
Atlas/C1/Cradle has no body or spinous process
True
What does atlas have for weight bearing
Lateral masses
True or False:
The superior facets of atlas are convex
False
What do the superior facets of atlas accept
Convex occipital condyles
What type of joint is the OA joint
Planar synovial joint
How much flexion does the OA joint account for
About 20 degrees
How much extension does the OA joint account for
About 20 degrees
How much side bending does the OA joint account for
About 5 degrees
How much rotation does the OA joint account for
About 1 degree
True or False:
The inferior facets of atlas are slightly convex
True
True or False:
Atlas has a facet on the internal surface of the anterior arch
True
What does the internal facet on atlas do
Accepts the dens (odontoid process)
Which way is the roll with side bending right
Right roll
Which way does the right and left OA move during right lateral flexion
Right: Inferomedial
Left: Superolateral
During right rotation what happens to the left and right OA
Right: Posterior and superior
Left: Anterior and superior
What is the vertical extension of C2
Dens/Odontoid process
What shape are the superior zygapophyseal joints
Convex
How are the inferior facets of C2 oriented
40 degrees
Which way do the inferior facets of C2 face
Medial and anterior
How many joints compose the AA joint
3
What are the 3 joints of the AA joint
1 Median atlanto-axial joint
2 Lateral atlanto-axial joints
What type of joint is the median AA
Synovial trochoid (pivot)
What type of joint are the lateral AA joints
Synovial planar
How much rotation does the AA allow
40 degrees
How much flexion and extension does the AA joint allow
0
How does the AA joint prevent flexion and extension
Ligament restrictions
Why does the AA prevent flexion and extension
To protect the brainstem/spinal cord
What are the arthokienmatics of the median AA joint
Spin
During right rotation which way do the right and left zygapophyseal joints of C1 and C2 move
Right: Posterior Inferior
Left: Anterior Inferior
What is Fryette’s Law I
Within the spine rotation and sidebending occur in opposite directions
So if you had right sidebending and applied Fryette’s Law I which way is the rotation
Left
Is the rotation noticeable
No
What is Fryette’s Law II
Within the spine rotation and sidebending occur in the same direction
So if you had right sidebending and applied Fryette’s Law II which way is the rotation
Right
Which degree are the superior facets of C3 oriented
40 degrees
What does neutral or non-neutral refer to
The sagittal plane
Which one of Fryette’s Law applies at C2/C3 junction
Fryette’s Law I
What type of joint is between the zygapophyseal joints of C3-C7
Plane synovial
What is the meniscoid properties of C3-C7
Soft tissue structure like menisci in the knee located between the zygapophyseal joints
What is the zygapophyseal joints composed of for C3-C7
Joint lined by hyaline cartilage surrounded by a capsule with menicsal inclusions
What do the meniscal inclusions between the Z-joints do
Guide/direct motion (keep train on track)
True or False:
You can impinge the menisci in the Z-joints
True
What are the menisci innervated by
Medial branches of cervical posterior rami C2-C8
Can the menisci of the Z-joints be a source of referred pain
Yes
Where does the C6/7 Z-joint refer
To the inferior angle of the scapula
Do the cervical IV discs have annulus in the back
No
What is the back of the cervical IV disc called
Uncovertebral cleft
Do the cervical IV disc have a concentric annulus
No
How much of the disc does the nucleus pulposus comprise in the cervical IV disc at birth
25%
How much of the disc does the nucleus pulposus comprise in the lumbar IV discs at birth
50%
What is the composition of the IV disc of the cervical vertebrae in adults
Fibrocartilage with no gelatinous component
What does genic mean
Produced by or from
What are possible sources of disc related pain in the cervical spine (2)
- Strains or tears of annulus fibrosous
2. Strains of the lateral parts of PLL
What Fryette’s Law refers to the typical vertebrae
Fryette’s Law II
Can we sidebend left and rotate right in the cervical spine
Yes
How can we sidebend left and rotate right in the cervical spine
Rotation at AA and side bending left in colum
Which way do the facet joints move during flexion
Superior and anterior
Do the facet joints have a roll
No
Why don’t the facet joints have roll
They are planar joints
What happen to IV foramen during flexion
Open or gapping
Which way do the facet joints move during extension
Inferior and posterior
What happens to the IV foramen during extension
Approximation or closing
Which way do the facet joints move during right side bending
Right: Posterior inferior
Left: Anterior superior
What happens to the IV foramen during right side bending
Right: Close
Left: Open
During right sidebending what do the facet joints move like
Right: Extension
Left: Flexion
During right rotation what happens to the facet joints
Right: Posterior inferior
Left: Anterior superior
Where does the most flexion and extension occur in the C-spine
The lower C-spine
When is the alar ligament taught ad slack
Taught: Flexion
Slack: Extension
During right rotation what happens to the alar ligaments
Right: Slack
Left: Taught
At what point does the alar ligament get sprained
Greater than 20 degrees
What is the sequence of whiplash for a rear end accident (5)
- Body rises
- Head goes into extension and mouth opens
- Body descends
- Head goes into flexion and mouth closes
- Back to normal position
What way does the head move first
The direction the force is applied
What happens to the articular processes during a whiplash injury
The tip of the inferior articular process of superior vertebra chisels into the surface of the superior articular facet of inferior vertebra
Why does the articular process chisel into the articular facet
Compression during whiplash move the IAR causing it to be in the vertebral body causing a greater inferior component
What does IAR mean
Instantaneous axis of rotation
True or False:
The IAR can change at any moment
True
What happens to the facet joints with extension
They come together
What happens to the annular fibers with a disc protrusion
The annular fibers are still intact
What are the 2 types of disc protrusion
- Localized annular bulge
2. Diffuse annular bulge
What direction is a localized annular bulge
Usually lateral
What direction is a diffuse annular bridge
Usually posterior
What happens to the annular fibers with a disc prolapse
Annular fibers disrupted (tiny hole)
What has occurred with a disc prolapse
The nucleus has migrated through the inner laminar layers, but is still contained
What happens to the annular fibers with a disc extrusion
Annular fibers are disrupted
What has occurred with a disc extrusion
Nucleus has broken through the outer most layer
What happens to the annular fibers with a disc sequestration
Annular fibers disrupted
What has occurred with a disc sequestration
Nucleus separate from disc and now is in the spinal or IV canal
When do disc sequestrations require surgery
When the disc is irritating the spinal cord
What happens if no surgery is needed to fix a disc sequestration
The body sees it as a foreign object and gets rid of it
What part of the disc is innervated
Outer 1/3
What percent of people 40 and older have a herniation
60%
What type of repeated movement does an upper cervical posterior derangement respond to
Protrusion because the upper cervical spine extends
What do the suboccipital ghost muscles do
Put compression on the suboccipital nerve
What does compression of the suboccipital nerve cause
Headaches overtime
What are guy wires
Wires on cellular towers that support the tower
What is there a balance of with guy wires
Tension, length, and strength
True or False:
Guy wires don’t need to be in balance
False
What can a forward head cause overtime
Retrusion and depression of the mandible
What happens because of the depression to the muscles
Adaptive lengthening of elevators and adaptive shortening of depressors
What happens because of the retrusion to the TMJ
Compression overload of the TMJ articular cartilage
What are the 4 types of disc herniation
- Disc protrusion
- Disc prolapse
- Disc extrusion
- Disc sequestration
Motivation
IT’S ALMOST TIME TO BALL HARD
