Biomechanics

Front 1

- In a superior –inferior direction through the dens

Back 1

demonstrate the axis of rotation for C1/C2 flexion

Front 2

In a medial lateral direction- through the lower vertebrae

Back 2

demonstrate the axis of rotation for T1/T2 sidebend

Front 3

In an anterior posterior direction through T2 body

Back 3

Describe the orientation of the superior and inferior articulating facets between the occiput and C1

Front 4

Inferior facet of the occiput, the condyles, are convex and the superior articulating facets on C1 are concave in an anterior/posterior direction

Back 4

Your patient lacks OA flexion. What arthrokinematic motion is necessary for OA flexion?

Front 5

Posterior glide of the occiput

Back 5

How much motion is there in flexion/extension at the OA joint?

Front 6

25 degrees total

Back 6

How much motion is there in OA sidebend and rotation?

Front 7

5 degrees sidebend, should be no rotation

Back 7

Describe the orientation of the superior articulating facets of C2?

Front 8

Downward sloping shoulders

Back 8

How much one sided rotation is available at this joint?

Front 9

45 degrees

Back 9

Describe the orientation of the C4-C5 spinal unit? What arthrokinematics motion occurs here during flexion?

Front 10

inferior facet of C4 faces 45 degree orientation from the frontal plane facing anterior and the superior facet of C5 faces 45 degree orientation from the frontal plane facing posterior.
Arthrokinematic- allows forward and superior gliding

Back 10

What osteokinematic motion is the greatest in the upper thoracic spine?

Front 11

Osteokinematic rotation

Back 11

In the lower cervical Spine- what structure limits Sidebend and translation?

Front 12

The uncinate process

Back 12

In the upper cervical spine, which Ligament prevents anterior shear of C1 on C2?

Front 13

Transverse ligament

Back 13

Which ligament in the upper cervical spine contributes to coupling of motion?

Front 14

Alar ligament

Back 14

In the upper cervical spine, the ligamenutm flavum now becomes the?

Front 15

Posterior atlantal occipital membrane and posterior atlantal axial membrane

Back 15

In the mid thoracic spine, what structure limits extension?

Front 16

The downward pointing SP and ALL

Back 16

In the lower thoracic spine, what structure limits rotation of the spine?
The vertical direction of the thoracic facets

Front 17

Upper cervical instability- stretching or trauma to alar or transverse ligament,
odontoid fracture

Back 17

Are symptomatic Herniated discs very common in the thoracic region?

Front 18

no

Back 18

Describe 2 clinical pathologies that are common in the thoracic region

Front 19

Pathological fractures
Herniated Discs- not necessarily causing pain
Space Occuping Lesions- ie- tumors- not common- but could be significant in this region as the central canal is small
Scoliosis- Common- however, we did not discuss. Refer to Chapter 9

Back 19

Describe the coupling patterns for the thoracic spine- be specific.

Front 20

In flexion coupling is to the same side – ipsilateral
In extension or neutral-coupling is to the opposite sides

Back 20

What structures and or pelvis position contribute to stability of L5 on S1?
anterior longitudinal ligament, iliolumbar ligament, orientation of facets in frontal plane, posterior tilt of pelvis

Front 21

Disc pressure is large when one holds a weight in front of body, esp. when holding a weight
Sitting in a slouched posture produces greater discal pressure than sitting erect
Sitting with back arched or curled towards knees

Back 21

Describe the trend of flexion and extension and rotation ROM as you descend cranial to caudal from the thoracic through the lumbar spine?

Front 22

Flexion and extension increases as you move down the thoracic spine and into the lumbar spine
Rotation starts higher in the thoracic region and decreases as you move into the lumbar spine

Back 22

What is the % of load bearing in the healthy lumbar spine on the disc/body vs. the facet joints?

Front 23

Facets carry 20% of the load
Disc/body carries 80% of the load

Back 23

How much combined motion is there in the lumbar spine in rotation?

Front 24

motion is in the opposite directions

Back 24

Explain how an excessive anterior pelvic tilt increases the anterior shear force on the L5-S1joint?

Front 25

The anterior shear force increases because the sacrum tilts forward and therefore makes the L5 body want to slide forward in the direction of the shear force

Back 25

List 3 factors that can contribute to disc herniation

Front 26

 Propensity for fissures or tears in annulus
 Sufficiently hydrated NP
 Inability of posterior annulus to resist radial pressure from nucleus
 Axial loading applied over a flexed and twisted spine

Back 26

Describe the effect of lumbar extension on the facet joints, intervertebral disc and the intervertebral foramen?

Front 27

The inferior facets slide inferiorly and posteriorily

Back 27

Your patient presents with lumbar stenosis. Describe a specific exercise which would be favorable for this patient and why?

Front 28

Spinal stenosis can be defined as degeneration of one or more spinal segments, producing a narrowing of the spinal canal.
- put them on their back, bringing their knees to their chest

Back 28

Your patient presents with a posterior herniated disc. You assess that extension movement decreases her symptoms. Describe a specific exercise, which would be favorable for this patient?

Front 29

Back extension exercises

Back 29

You have a patient with back pain, who constantly has a slumped posture: how would you explain the consequence this would have on the joint capsule and the disc?

Front 30

Slumped posture can canse a thinking of the disc due to a decreased water concentration

Back 30

In sitting, perform an anterior pelvic tilt. What muscles are responsible for the movement?

Front 31

Hip flexors and back extensors

Back 31

What are the positive effects of sitting in anterior pelvic tilt?

Front 32

Reduces pressure on disc

Back 32

What are the negative effect of sitting in anterior pelvic tilt?

Front 33

increase force on facet joints
and increase anterior shear of L/S1

Back 33

In sitting, perform an posterior pelvic tilt. What muscles are responsible for the movement?

Front 34

Hip extensors and abdominals

Back 34

What are the positive effect of sitting in posterior pelvic tilt?

Front 35

Reduces pressure on facets
Decreases anterior shear of L5/S1

Back 35

What are the negative effect of sitting in posterior pelvic tilt?

Front 36

Increased force on disc

Back 36

Specifically describe the motion at the SI joint, include location of axis of rotation and amount of rotation in the sagittal plane? Describe nutation and counternutation