Cervical Spine Anatomy/Biomechanics

Question 1

What comprises the Upper C-Spine?

Answer 1

Occiput, C1 (atlas), and C2 (axis)

Question 2

Gimme some facts about C1 vertebrae

Answer 2

Mobility for flexion and extension
Biconvex facet shape
Occipital condyles sit in the superior articular facets

Question 3

And some facts about C2?

Answer 3

Major upper cervical stabilizer
Uncovertebral joint
The dens sits infront of the brainstem, which can be bad news bears if the ligaments get damaged

Question 4

What positions can compromise the vertebral artery?

Answer 4

End range c-spine rotation, especially combined with extension and sidebend

Question 5

Transverse Ligament. GO!

Answer 5

C2 to occiput, covers the dens
“Cruciate”
Maintains integrity of dens to the anterior arch of C1
If it tears/becomes lax, then the dens may press into the brainstem/spinal cord

Question 6

Alar Ligament

Answer 6

Helps stabilize occiput on C2.

Limits rotation of median atlanto-axial joint

Question 7

Name the Special Tests for the Transverse and Alar Ligaments

Answer 7

Transverse: Sharp-Pursar (seated), transverse (supine)
Alar: Alar Ligament Stress Test (check rotation AND sidebending)

Question 8

Describe the biomechanics that occur during flexion and extension

Answer 8

Anterior translation during extension greater at O-C1 than C1-C2
Translational movement in sagittal plane
C1 translates inferiorly relative to C2 and inferiorly relative to occiput. Greatest at C1-2
Occiput slides anterior and medial on C1 in extension
Flexion: posterior and lateral

Question 9

Rotation Biomechanics

Answer 9

Greater amount of rotation at C1-2 than O-C1.

Rotational movement in a transverse plane

Question 10

Lateral Flexion Biomechanics

Answer 10

Rotational movement in frontal plane
Both joints exhibit ipsilateral axial rotation
Greater at C1-2
Occiput slides anterior and medial on atlas

Question 11

Coupling of C1-2 axial rotation and O-C1 lateral flexion

Answer 11

Axial rotation of the head to the LEFT results in a lateral flexion to the RIGHT
Caused by tightening of the alar ligaments

Question 12

Coupling between O-C1 lateral flexion and axial rotation C1-2

Answer 12

Lateral flexion of the head to the RIGHT DOES NOT result in axial rotation to the LEFT

Question 13

Coupling between axial rotation C1-2 and lateral translation O-C1-C2

Answer 13

Axial rotation of head to the LEFT results in translation of O-C1 to the LEFT and translation of C1-2 to the LEFT
Caused by ligamentous tension

Question 14

Coupling between flexion/extension and posterior/anterior translation between O-C1

Answer 14

From flexion to extension in the O-C1 joint, the occipital condyles translate anteriorly in relation to the atlas

Flexing O-C1 will bring C1-2 posteriorly

Question 15

Coupling between axial rotation C1-2 and longitudinal translation O-C1-C2

Answer 15

Axial rotation of the head from neutral causes the atlas to drop vertically in relation to the axis
Caused by morphology of the facet joints

Question 16

Where do the occipital condyles go during flexion and extension?

Answer 16

Flexion: Condyles move posterior and lateral
Extension: Condyles move anterior and medial

Question 17

When doing the Sharp-Purser Test, do you push the head anteriorly or posteriorly?

Answer 17

Don’t push that shit anteriorly! We don’t want to push the brainstem on the dens now do we?

Question 18

Describe the facets in the lower cervical spine

Answer 18

More medial to lateral
At a 45 degree angle
Role in flexion, extension, sidebend, rotation

Question 19

Uncovertebral Joints

Answer 19

Uncinate processes grow upwards from the superior aspect to each lateral vertebral margin towards the vertebral body above
Counters motion into sidebending
Facet joints are behind the uncovertebral joints
Do not have synovial fluid, but do have interstitial fluid
Highly vascularized and bleed extensively during trauma (whiplash)

Question 20

C-Spine Disc Lesions

Answer 20

Less common in the cervical than lumbar
Fissuring- upper C spine loses nucleus
Common source of local pain, referred pain into shoulder and scapula, and headaches
Trauma (whiplash): crush and traction injuries
Cloward areas

Question 21

What happens in hyperflexion injuries?

Answer 21

Annular fibers are pulled apart and often rupture off the bone (avulsion)

Question 22

What are the referral patterns of the following:
C2
C3,4,5,6
C5, C6, C7

Answer 22

C2: Only disc that refers pain superiorly into the head, commonly causes headaches
C3,4,5,6: Cloward areas, refer to the thoracic spine between the scapulas
C5,6,7: Lower motion segments, refer into the UE and usually proximal to the elbow.

Question 23

Describe the curvature in the lower cervical spine

Answer 23

Large lordotic curve in the lower c-spine, reversal of this in the upper c-spine

Full upper cervical flexion is not possible without lower c-spine extension

Question 24

Lower C-spine biomechanics

Answer 24

In extension, superior vertebra in a motion segment tilts and slides back, reverse occurs in flexion

Superior segment moves on the interior segment
Posterior and inferior glide into extension
Anterior and superior glide into flexion

Question 25

Patterns of cervical spine movements

Answer 25

Lateral flexion results in coupled ipsilateral rotation at each of the cervical motion segments

Rotation and sidebending are coupled together

Question 26

Swimmer asymmetries

Answer 26

If a swimmer only breathes to one side, they may have asymmetries in sidebend and rotation