spinal bio 2 test 1 Flashcards
2 main functions of the functional spine
rigidity
flexibility
what % of body weight does the spine hold
load bearing?
50% body weight
100% load bearing (picked up items)
flexibility ensures ________ & _______
mobility and plasticity
what is involved in proprioception
muscle spindal fibers
vestibular apparatus
righting reflex
what is the righting reflex
keeps eyes perpendicular to horizen
cervical spine has what mobility and stability
increased
decreased
thoracic spine has what mobility and stability
low mobility
increased stability
lumbar spine has what mobility and stability
increased mobility
increased stability
where is the center of gravity
anterior 1/3 of sella turcica
is the cranial curve anatomical
no
explain the lever system in the cranial curve
center mass of skull is the load
the condyles are the fulcrum
the posterior extensor muscles are the effort
where does the cervical curve end
inferior epiphysis of T1
what is the apex of the cervical curve
C4-C5 IVD
where does the thoracic curve begin and end
sup. epiph of T2——>inf epiph of T11
where is the apex of thoracic curve
T6-T7 IVD
Where is the apex of the thoracic curve in relation to the back of the trunk?
1/4 anterior
Is the cervical curve anatomical and functional?
yes
how does the cervical curve develop?
breastfeeding
curiosity
how does the lumbar curve develop?
crawling
where does the lumbar curve begin and end?
sup. epiph of T12—–>inf. epiph of S1
what is the apex of the lumbar curve?
L3 body
SC curve is anatomical not functional. T or F
T
In the fetus the occiput to L5 is kyphotic. T or F
T
When does the cervical curve develop?
birth —-> 5 months
When does the ALL begin to get stretched?
birth—–>5 months
when does convexity of the lumbar spine start?
5 months—->3 years
when should there be an obvious curve?
8 y/o
where should the GWL go in a radiograph?
- ant 1/3 of sella
- C5-6 IVD
- Body L3
- Femur head
- Lat. maleolus
What is the visual A-P GWL?
- Eop
- Scaoula
- Buttocks
- heels
What is the lateral visual GWL?
- tragus
- shoulder
- acetabulum
- knee
- lat maleolus
Why is there a slight physiological curve in the thoracic spine to the right?
heart
A lever gives _________
a mechanical advantage
forces are ______ or _______
parallel or perpindicular
a curve takes a vertical force and
transfers it to a horizontal
stress is _______ distributed among a curve
evenly
what is the bending moment?
force on the apex of a curve
what is an example of a class 2 lever?
wheelbarrow
foot
what is an example of a class 3 lever
arms
what is the goal of a curve?
to have the lowest bending moment with the highest flexibility
the force on the apex _____ at first then increases ________
slow at first
increases very quikly
wolfe’s law
the body will add bone to areas of stress
the mechanical advantage _______ quickly as the curve increases but _______ off
increases
levels
how many curves in the human spine?
4
what is the resistance to axial compression
R=(n)2 + 1
how much do the curves in the human spine increase resistance to axial compression?
8 1/2 times stronger
what does the delmas index measure?
clinical measurement of degree of overall curve in a spine
the # of curves in a spine determines what
resistance to axial compression
According to the delmas index, what is optimal curve?
95 %
According to the delmas index, what is regional hyper-curvature?
less than 94%
According to the delmas index, what is regional hypocurvature?
more than 96%
The leading theory is that the spinal curves are what?
arcs of circles
What is the basic spinal unit?
2 vertebra and all associated muscles and structures
Where does the ALL begin and end?
Basion—->skips ant. tubercle of C1—->sacral promentory
What does pre-loaded mean?
tension artificially induced in the structural elements in addition to any self-weight or imposed loads they may carry. It is used to ensure that the normally very flexible structural elements remain stiff under all possible loads.
The ALL limits what movement?
extension
The ALL is a wide ____ band
elastic
The ALL naturally wants _______
kyphosis
Where does the PLL begin and end?
Foreamen magnum——>skips C1—–>posterior C2 body—–>post. S1
The PLL is ________ attached
loosely
The PLL narrows between the
pedicles
The ligamentum flava begins and ends where?
C2-3—–>L5,S1
What is the most elastic ligament in the human body?
yellow ligament
The intertransverse ligaments limit what movement?
contralateral lateral flexion
The intertrasverse ligament go from where to where?
proximal tp to the tp below
What is the anterior column?
vertebral bodies + IVDs
what is the posterior column?
Z column + vertebral arch
What is the function of the anterior column?
weight bearing
The load on the anterior is passed where?
posteriorly
The anterior column is purely ______
anatomical
The anterior column is _______ adapted
passive
The main function of the posterior column is
mobility and motion guidance
the posterior column is not passive due to
muscles——mainly interspinalis
Internal trabeculation patterns
vertical fibers resist
resist axial compression
Internal trabeculation patterns
A–P fibers run from
sup. epiph—–>spinous
Internal trabeculation patterns
A—P fibers part 2 run from
inf. epiph—->post zyg—->spinous
Internal trabeculation patterns
horizontal fibers resist
inward thrust (reenforce side walls)
Internal trabeculation patterns
oblique fibers run from
inf. epiph—–>side wall
the least stress is on what part of the vertebral body?
anterior
Where is the most dense bone?
pedicle
What are the most common clinical causes of compression fracture?
`oteoporosis
Forward head posture
kyphosis
what is loose packed position
where the joint is most open and capsule + ligaments are most relaxed
what is joint play
assesment of resitance from neutral and/or loose packed joint position
what is capsular feel?
some spongy give but increase in pain
pain is normally due to an
enlarged capsule
what is the end play zone?
end of passive ROM at the elastic barrier
What is ligamentous creep?
deformation of ligaments under continous load
what is the main functions of synovial fluid?
lubrication
bring in nutrients and evacuate waste
what is the articular cartilage composed of?
hylaronic acid
proteoglycans
type 2 collagen
what is an adhesion?
scar tissue
when is fluid film lubrication prevalent?
happens during light load
primary lubricant
increases movement
what is boundry lubricant?
is used when cartilage is heavily loaded
what are the properties of the zyg joints?
- change with volume of fluid; fluid excursion under pressure into hyaline cartilage w/i 3 min
- hyaline cartiladge can go under massive pressure and keep shape (plyable)
- As joint loaded and unloaded, the cartilage and joint exchange nutrients & waste
What are the four main biomechanical characteristics of ligaments and tendons?
- passive structures that are important to stability
- get stiffer with increased strain
- ligaments in joint capsules act as static restraints
- tendons transmit tensile loads from muscle to bone
elastic: collagen ration in ligamentum flava
2:1
Both tendons and ligaments have
mechano/proprioceptors
Damage to ligaments is due to
rate of impact
amount of load
what is hysteresis?
energy lost due to deformation
What is the weakest point of a ligament/tendon?
insertion point
T or F
corticosteriods inhibit collagen synthesis?
T
What is George’s line?
a line down the posterior vertebral bodies on a x-ray
Henri gillete’s fixation theory
- muscles
- ligamentous
- articular
primary—–>secondary
Henri gillete’s fixation theory
muscles
secondary; minor fixation, palpated tender, taut muscle fibers, hyperaestetic, little end play
Henri gillete’s fixation theory
ligamentous
ligaments shorten slowly & lose stretch ability. abrubt block w/ no give; improvement is partial and takes time to acheive
Henri gillete’s fixation theory
articular
total fixation, palpates as a full blockage
pathology-ankylosis (fusion)
(not-always adjustable)
Henri gillete’s fixation theory
primary leads to
secondary
Henri gillete’s fixation theory
secondary fixations are
compensatory
Henri gillete’s fixation theory
adjusting the secondary alone will
never change the primary
Lumbar facet syndrome
- localized pain sometimes radiates to butt and thighs
- often sudden onset
- decrease weight bearing
What is dynamic coupling?
two or more motions that necessarily occur simultaniously
What 2 factors are involved with dynamic coupling?
- coupling mech. joint surface structure
2. ligamentous factors
Thoracic lumbar coupling
2 mechanisms
- lateral flexion/ contralateral rotation are strongly coupled
- rotation/contralateral lat. flexion are not coupled
mechanisms of coupling
anterior mech.
IVD
Lat. flex—contralateral wedge opening/ipsilateral annulus
mechanisms of coupling
posterior mechanisms
- lat. flex—> contralateral streched ligaments
effect maximized on intertransverse, capsule, & yellow lig. - pull arch ipsilaterally to shorten arc
T or F coupling must happen both ways
F
Rotation is defined by
the vertebral body
Cervical coupling
lateral flexion is coupled with ipsilateral roation
IVD structure
nucleus pulposis
- yellowish-white, translucent gel
- hydrophilic muco-polysaccharide matrix w/ CT cells and mature chondrocytes
- up to 88% H2O from surrounding tissues mostly through cartilage of epiphysis
- imbibation decreases with aging (fibrosis is common)
- avascular, no nerve supply
- derived from the notochord
IVD structure
Annulus fibrosis
- 95% collagen
- 12-20 lamina
- multiple orientations
- more oblique —->closer to nucleus
5 attached to VB by Sharpe’s fibers
IVD structure
annulus/nucleus boundry
- no distinct boundry
- only volume-no shape- amorpous
- forced into roughly spherical shape
active joint movement
requires muscular contraction
active joint movement
factors determining active ROM
- articular design
2. inherent tension or resiliency of the associated muscle
passive joint movement
- when dr. must bring joint through ROM
- passive joint movement has greater ROM than active joint movement
- takes muscle resistance out of play
passive joint movement
factors determining ROM
- articular design
2. flexibility of soft tissue
restriction
can occur anywhere along the ROM
Active ROM restriction
1.myofascial shortening (splinting, aging)
passive ROM restriction
- due to shortening of joint capsule, ligaments
close packed position
- joint surface = compressed
2. joint capsule and ligaments are at tightest
adjustments
- correct subluxations
2. neurological component
manipulative therapy
- often applied along planes of resistance to increase ROM
- decrease pain
- occurs in para-physiological space
end play zone
- must go beyond active ROM
2. movement at end of passive ROM right before elastic barrier
end play
qualitative assessment of resistance at end of passive joint movement
abrupt & extreme pain
bone on bone contact
global ROM
between regions
segmental ROM
between two vertebra
physiological barrier
end of active ROM
elastic barrier
- end of passive ROM
2. adjustment set up just prior to elastic barrier
anatomical limit
- joint trauma or pathology
2. strains and sprains
para-physiological space
- place where manipulation takes place
- some adjustments take place here (diversified)
- where cavitation comes from (nitrogen release
IVD function
hydrophilic nucleus
- incompressible but flexible
2. acts as ball-bearing between two plates=swivel joint
6 degrees of freedom
three rotations
- F/E (sagittal)
- L/R Lateral Flexion (Coronal Rot)
- L/R rotation (Axial rot)
6 degrees of freedom
three translations
- anterior—>posterior gliding
- L/R gliding
- Compression and Traction
rotation definition
movement around a point
translation definition
movement in a straight line
Water Imbibition
nucleus communicates with ______ bone via _________ in cartilage
- spongy
2. micropores
Water Imbibition
what absorbs water
resting disk
Water Imbibition
what happens to the pressurized disk?
- water is squeezed out
quickly at first then levels off
Water Imbibition
how much height can be lost over the course of a day due to pressure?
3/4 of inch
When one ages what happens to the nucleus?
- more fibrotic
2. decreases hydrophilic properties
How does aging directly cause subluxation?
loss of IVF space=pressure on nerves
What is the goal of pre-loading?
gives greater resistance to forces of compression and lateral flexion
What are two factors that maximize pre-load?
- nucleus has a set volume
2. water imbibition
T or F
pressure on the nucleus can be zero
F
due to water imbibition
T or F
the nucleus translates radial load to axial load
F
axial to radial
T or F
An increased load will make the annulus stiffer
T
How much axial load is on the nucleus?
75%
How much axial load is on annulus fibrosis?
25%
What is the self-stabiliztion mechanism in the IVD?
the IVD returning to its neutral state
What is the neutral state of the IVD?
- maximum thickness
- minimum stress on annulus
- level end plates
What is the IVD response to axial load?
- IVD gets stiffer
Why does the IVD stiffen under axial load?
- Nucleus bulges against annulus
2. annulus must increase resistance to prevent prolapse
Dampening oscillation happens within _ sec
1
What is the nucleus’ response to asymetrical load?
compresses ipsilaterally/ depressurizes contralaterally
What is the annulus’ response to asymmetrical load?
compresses ipsilaterally/ tensioned contralaterally
The nucleus under asymetrical load wil press against the contralateral side and _______
the annulus?
tension
How many disks in the spine are level to the ground?
4
What is the annulus response to torqueing load?
50 % becomes stiffened due to concentric alternating pattern
What fibers are tightened in torqueing load?
oblique fibers in the direction of motion
Why is rotation a compromising position?
The annulus is only 50% stiffened
What effect happens during torquing load?
screw down effect
Direction of sheer is direction of
inferior tilt
sheer increases as you move ______ from the disk
away
T or F neutral disks have sheering force?
F
What are the four IVDs that are level to the ground?
- C4/C5
- T6/T7
- L2/L3
- L3/L4
What disks are extended?
- C2/C3
- C3/C4
- T7-L1
What disks are flexed?
- C5-T5
2. L4/L5
What happens to extended disks during flexion?
neutralizes sheering force
What happens to flexed disks during flexion?
increase sheering force
Which disks have the most problems over lifespan?
flexed
What is the most common injured disk in the body?
L5/S1
What type of sheer comes from left lateral flexion?
anterior and left sheer
Where is herniation of the disk most common?
posterolateral
What is the weakest part of the annulus?
lateral
Where is the maximum vulnerablity of the annulus?
- contralateral to rotation in flexed disks
2. ipsilateral to rotation in extended disks
During right rotation where are flexed disks most commonly injured?
left side
During right rotation where are extended disks most commonly injured?
right side
traction =
axial tension
What does traction do?
seperates end plates (brings fluid into disks)
What happens to the nucleus during traction?
consolidated inward & upward
What happens during extreme traction?
damage to the annulus
What determines the amount of mobility in a region?
Amount of soft tissue associated
Where is the cervical apex in relation to back of neck?
1/3 anterior
Where is the thoracic apex in relation to the back?
1/4 anterior
Where is the Lumbar apex in relation to the back?
1/2 anterior
What is the average thickness of an IVD in the cervical region?
3 mm
What is the average thickness of an IVD in the thoracic region?
5 mm
What is the thickness of an IVD in the lumbar region?
9 mm
T or F
Disk thickness is more important to mobility than overall percentage of soft tissue?
F
What is the percentage of soft tissue in the cervical region?
28%
What is the percentage of soft tissue in the thoracic region?
16%
What is the percentage of soft tissue in the lumbar region?
25%
The lumbar region has a high percentage and very thick IVDs which indicates ________ _______ and ________
high mobility and stability
In the cervical spine the nucleus is what percentage of disk width?
30%
In the cervical spine the nucleus is in what relation to center?
slightly posterior
In the cervical region the nucleus is where in relation to the axis of motion?
directly under
In the thoracic region the nucleus is what percentage of disk width?
30%
In the thoracic region where is the nucleus located in relation to center?
slightly posterior
In the thoracic region where is the nucleus located in relation to the axis of motion?
very posterior (low mobility)
In the lumbar spine the nucleus is what percentage of disk width?
40%
In the lumbar spine the nucleus is located where in relation to center?
posterior (more than cervical and thoracic)
In the lumbar region how much of an increase (over the other regions) in surface area does the nucleus have?
80%
In the lumbar region where is the nucleus located in relation to the axis of motion?
directly under (good mobility)
The interspinous ligaments limit what movement?
flexion
What region has the most defined intertransverse ligaments?
lumbar
What limits contralateral lateral flexion?
intertransverse ligaments
What region is most prone to compression fracture?
thoracic
What vertebra are most commonly injured due to compression fracture?
T7/T8
T12/L1
What factors impact biomechanical properties?
- aging
- pregnancy (relaxin)
- corticosteriods
- NSAIDs
Hyperesthetic definition
increased sensitivity to touch
ankylosis definition
joint fusion
Protrusion/bulging definition
position of nucleus shifted within annulus
but still contained
2 types of protrusion/bulging
concentric
radial
concentric protrusion
4 points
- the protrusion is 360 degrees
- nucleus is seeping into the outside of the annulus
- delamination is a precursor to concentric protrusion
- unlikely to reconsolidate/ rupture
the disk is not usually the cause of the problem, but a __________
symptom
What is the best way to evaluate a disk?
MRI
delamination definition
the annulus fibrosis fibers have slight rips due to microtraumas
radial protrusion
4 points
- nucleus cuts across annulus layers
- usually posterolateral
- better chance of reconsolidation
- more likely to rupture
a straight posterior radial protrusion is the ______ type of protrusion and the ______ most common
worst
2nd
An anterior protrusion is _______
rare
what is a prolapse/rupture/herniation/extrusion?
nucleus is free of annular containment
A subligamentous prolapse may be reconsolidated if it is ___________
non-sequestered
What happens during a subligamentous prolapse?
- nucleus is under the PLL
- the nucleus may move up or down
- the nucleus may be sequestered or non-sequestered
what does sequestered mean?
fragmented outside of annulus to where part of the nucleus becomes isolated
What does frank prolapsed mean?
- nucleus breaks through PLL
- nucleus is in the neural canal
- may be sequestered or non-sequestered
Frank prolapses increase ________ ________
nerve entrapment
What is cauda equina syndrome?
- massive directly posterior prolapse
- entire nucleus is expelled
- can cause total paralysis of legs and complete loss of bladder control
Which has a better possibility of naturally healing, protrusion or prolapse?
prolapse
T or F
During a protrusion disk function remains intact.
T
T or F
during a prolapse ankylosis will occur within 1-3 years.
T
T or F
protrusion rarely has repeated occurences.
F
T or F
protrusion has a low possibility of long term healing
T
The spinal cord ends at
T12-L3
What are some conservative ways to treat disk issues?
- traction
- bed rest
- muscle relaxors + pain killers
- bracing
What are some preventative measures for disk issues?
- H20
- posture
- proper weight
- lifting properly
- chiropractic care for subluxations
What are two conditions that lead to disk trauma?
- delamination of Annulus Fibrosis
2. precipitating event
Most disk trauma happens after the age of
40
T or F
disk trauma is more common in women
F
A precipitating event most likely happens because of two factors.
- sudden excessive disk loading
2. most likely flexion sheer
During disk trauma pain results from
2 factors
- ligament trauma (dull, achy)
2. nerve root entrapment (sharp, can radiate)
What is the Val Salva reaction?
a diagnostic tool for disk trauma consisting of
- bearing down
- closes all sphincters in abdominal area and thorax
- happens during bowel movement naturally
What are two surgical options for disk trauma?
- decompression (laminectomy)
2. excise the disk
