Exam #2 (Lecture 6) Flashcards
Where is ligamentum flavum located?
anterior surface on lamina to posterior surface of one below
(insert picture)
ligamentum flavum is made of ______% elastin, ____ % collagen
80, 20
describe where there is compression forces for ligamentum flavum
absorbs some intervertebral compression forces near end flexion.
- constant resistance throughout wide range of flexion with 35% elongation
what is the compression on ligamentum flavum like in neutral?
small but constant compression/stabilization in neutral
what is the thickest ligament in the lumbar region?
ligamentum flavum
where is the interspinous ligament located?
fills space between adjacent spinous processes
what does the interspinous ligament resist?
resists separation of adjacent spinous processes - resisting flexion
deep interspinous ligament has more _____ blend with which ligament?
elastin blend with ligamentum flavum
superficial interspinous ligament has more _____ blend with which ligament?
collagen blend with supraspinous ligament
where is the supraspinous ligament located?
attaches between the tips of the spinous processes
what does the supraspinous ligament resist?
resists separation of adjacent spinous processes - resisting flexion
* like interspinous ligament
what region is the supraspinous ligament well developed?
cervical region
when the supraspinous ligament resistss flexion more strongly, what does that mean?
there is more collagen
describe the characteristics of intertransverse ligaments
poorly defined
thin, membranous
intertransverse ligaments are taut in _______
contralateral lateral flexion (contralateral SB)
intertransverse ligaments are slightly tight in ______
forward flexion
describe the characteristics of anterior longitudinal ligaments
long, strong, straplike
narrow at cervical spine
widens in lower spine
where are intertransverse ligaments located?
between transverse processes
(insert picture)
where are anterior longitudinal ligaments located?
entire anterior surface of vertebral bodies (deeper fibers blend with and reinforce discs)
anterior longitudinal ligaments run from where to where?
basilar part of occipital bone to sacrum
anterior longitudinal ligaments are taut in _____ and slackened in _______
taut - extension
slack - flexion
where are posterior longitudinal ligaments located? runs from where to where?
entire length of posterior surfaces of all vertebral bodies - within vertebral canal anterior to spinal cord
runs from C2-sacrum
where on the spine are posterior longitudinal ligaments more broad? narrow?
broad - cranially
narrow - lumbar region
Opposite of ALL
posterior longitudinal ligaments are taut in ______
flexion
Opposite of ALL
what are the roles of spinal ligaments? (4)
limit motion
help maintain spinal curves
stabilizer
protects spinal cord and nerve roots
where are capsular ligaments of the apophyseal joints located?
attach to the entire rim of the facet surfaces
capsular ligaments of the apophyseal joints are a blend of what? what does that mean?
blend of elastin and collagen
tough to keep integrity of joint/flexible to allow arthrokinematics
what are the capsular ligaments of apophyseal joints reinforced by?
adjacent multifidus/ligamentum flava
capsular ligaments of apophyseal joints are slack in ______ and some fibers are taut in ______
slack - neutral
taut in end ROM
in the sagittal plane, a posterior ligament will stretch in which direction?
flexion
in the sagittal plane, an anterior ligament will stretch in which direction?
extension
what is neutral zone?
the amount of intervertebral movement that occurs with the least passive resistance from the surrounding tissues (i.e. ligaments)
“wiggle room”
used to quantify the amount of segmental instability that is present
thought to be a better measurement of instability than spine ROM
what does it mean if the neutral zone grows larger? how is it increased?
more laxity or instability in the spine to control and more demands are placed on the stabilizing systems
increased with injury or weakness of surrounding tissues
too much wiggle room indicates:
not enough wiggle room indicates:
1 - hypermobile
2- hypomobile
* one side can be hypo, one hyper
what does the passive system consist of? (5)
bony structures
ligaments
joint capsules
discs
passive portion of musculotendinous units
what does the passive system do?
sends feedback to the neural subsystem about joint positions and challenges to stability at the passive level
give an example of something at the passive level
trauma / sprained ankle
can heal but never be the same
why are ligaments part of the passive system?
they are positioned to protect the joint from excessive movement - creates stability.
what is the active system thought to be?
muscles (and tendons)
what does the neural subsystem do?
receives and transmits information from and to the other two systems to manage spinal stability
aka nervous system
what is spinal instability?
loss of intervertebral stiffness that can lead to abnormal and increased intervertebral motion
*increased wiggled room
what two levels can core stability be viewed from?
local segmental level (size and control of neutral zone)
global spine level
When the neutral zone has more slide, glide and rotation between vertebrae, the neutral zone is _______. This increases with ______ and _______ and decreases with _______
neutral zone becomes unstable
increases with injury and degeneration
decreases with muscle force
describe characteristics of C3-C6
superior surface:
inferior surface:
small rectangular bodies
curved and notched superior/inferior surfaces
superior: concave side to side with hooks - uncinate processes
inferior: concave ant/post - joint forms between hooks/recess
where are the joints of luschka located?
uncovertebral C3-4 through C6-7
C3-C6:
- short and curved posterior-lateral:
- very thin:
- large:
- short, some bifid:
- short lateral extensions with ant/post tubercles, unique to cervical spine, attachments for muscles:
- pedicles
- laminae
- vertebral canal
- spinous processes
- transverse processes
C3-C6:
what do consecutive articular processes form?
“pillar” with apophyseal joints (facet joints)
facets are smooth and flat
which direction does superior facets face (C3-C6)?
inferior?
superior: posterior/superior
inferior: anterior/inferior
** bicep curl example: down = anterior (front of hand)
up = posterior (back of hand)
C1:
- supports:
- does not have:
- 2 large lateral masses joined by:
- ALL attaches to:
- superior concave facets support:
- inferior articular facets:
- head
- body, pedicle, lamina, or spinous process
- anterior and posterior arches
- anterior tubercle
- cranium
- flat/slightly concave
C2:
- large, tall body holds:
- has:
- short:
- spinous process:
- dens: ridged vertical axis of rotation for head
- superior articular processes, pedicles, inferior articular processes (face ant/inf)
- transverse processes
- bifid, palpable
C7:
- (smallest/largest) of cervical:
- can have a cervical rib off:
- spinous process:
- largest
- transverse process
- not bifurcated
typical thoracic vertebrae T2-T9:
- directed posterior:
- short, thick:
- downward slanting:
- narrower than cervical:
- large and project posterior:
- superior articular facets face:
- inferior articular facets face:
- aligned in frontal plane:
- spinal nerves go through:
- pedicles
- lamina
- spinous process
- vertebral canal
- transverse processes
- posterior
- anterior
- apophyseal joints
- intervertebral foramina
what is atypical about T1?
full costal facet - entire rib
demifacet for rib 2
spinous process elongated
what is atypical about T10-T12?
single full costal facet
what are the three functional components of typical intervertebral joints? what do they do?
1- transverse/spinous processes (increase mechanical leverage of muscles and ligaments)
2- apophyseal joints (guiding intervertebral motion)
3- intervertebral disc (absorb and distribute load, greatest adhesion, axes or rotation, spacers, provides passage for nerves)
describe the osteokinematics of an intervertebral joint (5)
small movements
large angular motion
3 cardinal planes
axis for each interbody joint
rotation reference point is anterior
describe the 3 things happening in arthrokinematics at the apophyseal joint
1- approximation: facets close, usually by compression force
2- separation: facets open, usually by distraction force
3- sliding (gliding): facets translates in linear direction, caused by force directed tangential to joint surfaces
apophyseal joints:
- ___ pairs:
- ____ joints
- lined with:
- enclosed by:
- acts as:
- most frequent in:
- 24 pairs
- plane joints
- articular cartilage
- synovial well-innervated capsule
- mechanical barricades
- upper cervical and lumbar
what are subcapsular fat pads that sometimes exist in facet joints?
superior and inferior margins of joint and fibro-adipose meniscoids
what does a horizontal orientation of facets do?
favor axial rotation
what does a vertical orientation of facets do?
block axial rotation
where are intervertebral joints located?
C2-3 through L5-S1
what three things are intervertebral joints comprised of?
disc
endplates
vertebral bodies
what is the disc made up of?
nucleus pulposus:
- pulplike gel mid to posterior aspect of disc
- 70-90% water in youth
annulus fibrosis
what does the disc do?
hydraulic shock absorbing system
dissipates and transfers loads across consecutive vertebra
why is the disc hydrophilic?
gel like, proteoglycan GAGs (water binding GAGs - likes water)
what kind of charge does the disc have?
negatively charged nature of disc resulting from charged groups on GAGs
what does the disc contain that synthesizes proteins and proteoglycan?
thin type II collagen fibers
elastin fibers
small number of chondrocytes and fibroblasts in the nucleus
how many rings of collagen fibers does the annulus fibrosis have? how many degrees from vertical?
15-25 concentric rings
65 degrees from vertical
what does the annulus fibrosis do?
- prevents distraction, shear, torsion due to angulation at 90% of torsion force to stretch fibers in direction of the force
- encase liquid based nucleus
what does the outer layer of annulus fibrosis contain?
disc only sensory nerves
what does the outer layer of annulus fibrosis bind to?
because it has more?
inner layer has more?
binds to ALL PLL
outer layer has more collagen
inner layer has more water
what happens to the vertebral endplates in degeneration or excessive/abnormal loads placed on them?
reduced permeability - reduced inhibits syntheses of proteoglycans –>
less proteoglycans, more collagen = less water –>
less ability to absorb and transfer loads –>
structural and functional failure (disc herniation, OA, annular tears)
the endplate calcifies cartilage
what should be happening in the disc with normal compressive forces?
produce hydrostatic pressure in disc and evenly distribute load protecting intervertebral and apophyseal joints
what percentage of the load is carried on intervertebral joints in standing at spine? what percent at posterior elements?
80% in standing
20% at posterior
how does the IVD act as a hydrostatic pressure distributor?
compressive loads push endplates inward to nucleus pulposus –>
NP slowly deforms outward in all directions (radially) –>
stretched rings of collagen and elastin create tension to resist/balance force. this uniformly transfers to vertebral bodies then returns when load is off
the IVD is __________
it resists a ______, _______ load (more rigid or flexible?)
has less resistance to _____, _______ loads (more rigid or flexible?)
viscoelastic
resists fast, strongly applied loads (rigid at higher loads)
less resistance to slow, light (flexible at low loads)
what everyday position has a higher load to the NP in the lumbar spine?
bending over (at lumbar spine) to lift a heavy object
- in general, holding/moving a heavy object increases load on the NP in the lumbar spine
what everyday position has the least amount of load to the NP in lumbar spine?
laying supine
true or false. leaning forward, whether sitting or standing, creates greater load on the NP in the spine than extending back or sitting straight up
true
sustained and full lumbar extension _______ pressure in discs.
water is ________ into the disc in extension
reduces
water can be reabsorbed
what is diurnal fluctuations and why do we experience this?
taller in the morning than night (creep)
laying in supine is low pressure, causing water to attract to the spine and swell slightly when sleeping –>
when WB, forces push water out of the disc
why are diurnal fluctuations related to age?
as we get older, proteoglycans reduce causing less water retention and less hydrostatic pressure
do you always experience symptoms with diurnal fluctuations?
no - not always symptomatic or loss of function
what is spinal coupling?
any movement of the spine in a plane is combined with an automatic and often imperceptible movement in another plane
think: muscle action, facet alignment, posture, ribs, stiffness, curve of spine itself
describe the movement of the atlanto-occipital (OA) joint? * use convex, concave
movement of cranium on atlas
occiput - convex condyles
atlas - concave facets
how many degrees of freedom does the OA joint have?
2 - flex/ext & SB
describe how the AA joint creates stability
what type of joint is it?
dens (C2) pushes into osseous-ligamentous ring (anterior arch of atlas and transverse ligament)
pivot joint
describe the facet joints in the AA joint
how many degrees of freedom?
pair of lateral facet joints
flat and close to horizontal plane
2 degrees of freedom - flex/ext and rotation
where does half of our rotation in the C spine come from?
AA joint
20-25% of neck flexion comes from what joint?
OA joint
rest from cervical spine (C2-C7)
normal ROM for:
- cervical flexion:
- cervical extension:
- lateral flexion:
- cervical rotation:
- 40
- 50-70
- 22
- 50
where is the tectorial membrane located? what attaches to it?
AA joint
posterior to transverse ligament
PLL/basilar attachment
where is the alar ligament (“check” ligament) located?
AA joint
runs side of dens to lateral foramen magnum
tough fibrous cords 1 cm
where are the intracervical apophyseal joints located?
what are they like?
how many degrees of freedom?
facets of C2-C7
like shingles on a roof at 45 degrees
movement in all 3 planes
what is the degrees for normal kyphosis?
40-45 degrees - all 3 planes of movement
true or false. lateral flexion is greater in thoracic region than lower cervical (C2-C7) region
false
SB similar to C2-C7
what position are intervertebral foramen most open? most closed?
open: flexion –> inferior facets slide superiorly and anteriorly, less joint surface contact
closed: extension –> inferior facets slide inferior and posterior, closed packed more joint surface contact
where is flexion and extension happening in protraction?
flexion: lower cervical region
extension: upper cervical region
where is flexion and extension happening in retraction?
flexion: upper cervical region
extension: lower cervical region
AA joint is designed for what movement?
rotation
