Lecture 4-5 Flashcards
Plane is determined by what?
flat surface determined by 3 points in space.
what planes do we deal with?
saggital - splits us side to side, frontal- splits front to back, transfers- top to bottom
What is plane motion?
motion in which all points of a rigid body move parallel to a fixed plane
What is a saggital plane motion, remember sagital splits us into right and left
Flexion and extension, because when you flex/extend the movement is parallel to the saggital plane.
What is normal frontal/coronal motion?
abduction adduction, because those movenets are parallel to the coronal plane
What is normal motion of tranverse plane?
rotation, turning head, twisting., parallel to tranverse plane
What are the dimential limitions of plane motion?
its two dimentional
What are the dimential limitionas of out of plane motion?
its three dementional, all points of rigid don’t move in single plane, circumvex
axis is what
line around which rotary movement or translation occurs
what are the directions of the x axus
- x-side to side axis, perpendicular to saggital plane
What are the directions of the Y axis?
y axis pointing up through skull, perpendicular to the transverse plane
What are the directions of the z axis
z axis, front to back, perpendicular to the coronal/frontal plane
Other name for z axis?
saggital
Other name for y axis
longitudinal axis
Other name for x axis
coronal/frontal axis
What is ment by degrees of freedom?
number of ways in which body can move
how many degrees of freedom does a spinal segment have
spinal segments have 6 degrees of freedom, 3 translations and 3 rotations,
What is instaneous axis of roation?
idea that when a rigid body moves in a plane, there is a point maybe a hypothetical extention that doesn’t move
what is used to describe any vertebral motion in a two dementional plane?
instaneous axis of rotation
Is the Instaneous axis of rotation the same for the entire spine?
No, its different for each section, thorasic, lumbar, cervical and different under different loads
what is the functional unit of the spine?
motion segment
What makes up a motion segment?
two adjacent vertebrae and their interconnecting disc, joints, capsule and ligaments
characteristics of a motion segment?
smallest spinal segment (2) exhibiting biomechanical characteristics similar to those of the entire spine with 6 degrees of freedom
what ligament is around articular fascets
capsular ligaments
what is the pedicle joint called?
zygapophyseal joint with a joint space
what is coupled motion?
two motions ocuring at the same time along different axes that cannot be produced without the other
what joints have loose packed position?
fascet joints are loose packed half way between flexion and tension
what is the loose packed joint position used for?
traction or joint mobilization
what makes up a lose packed joint position?
1) capsule and ligamens are most relaxed, 2) maximum joint play is possible, 3) articulation surfaces are maximally separated
what is a close packed joint position?
capsule and ligaments are maximally tightened with no joint play and maximal contact between articular surfaces
when would there be close packed joint position of spine?
flexion or extension of spine.
What spinal section is the most movable
cervical can do the most,
what is the least movable section?
probably the thorasic, can barely do anything.
What can the lumbar do best and worst?
Best at flex and extend, not so good at rotation
what cervical part has most rotation?
the first one and skull
does C1 do lateral bending?
nope
What does better flexion and extension?
Lumbar does better flexion while cervical does more extension
what has the best lateral flexion?
cervical can do the most,
what section has best and worst rotation?
lumbar has worst rotation wile cervical and thorasic is almost equal
where do the concyles of the occiput face?
laterally and inferiorly so they can sit in C1 articular facet
Where to the atlas C1 facets face?
medially and superiouly so they fit the condyles of occiput
what does the fascet/condyle joint allow?
rocking
In which direction does the occipit glide?
Occiput glides posteriorly to flex 10 degress
In which direction does occiput roll?
occiput rolls anteriorly to extend. 25 degrees
Where is the greates range of motion?
CO and C1 (atlas)
what is gliding and rolling during occiput C1 flexion?
Occiput rolls on side of flexion and glides on opposite side
what limits CO-C1 rotation?
alar ligament 5 degrees each side.
where does gliding and rolling happen during rotation?
glide posteriorly on side of rotaion and anteriorly on side opposites
what is the atlas axis joint around odointoid process called?
atlas odontoid joint
what type of joint is the atlas odontoid joint?
synovial
what is the ligament that ties odontoid process in?
transverse ligament
what is the cervical coupling pattern?
as you laterally bend right the cervicals compress on the right side and twist to the right
where is the alar ligament?
between occiput and odontoid.
where is the transverse ligament?
it goes around posterior aspect of odontoid.
what direction does articular surfaces of CI glide on C2 during flexion?
they glide posteriorly a little pit. So when head goes forward, it slides back.
what direction does C1 articular surface glide on C2 during extension
when head goes back, c-1 glides foreward. So its opposite.
what direction does C1 glide during lateral flexion?
C1 glides (translates) on C2 in the direction of lat flexion O rolls on side of flex and glides on opposite. Picture C1 squishing out from between O and C2 toward direction of lateral flexion.
what accounts for more than half of cervical rotation?
C-1 / C-2 rotation around the odontoid process
how does C1 glide during rotation on C2?
just like you would imagine, it glides back on the side its turning to and forward on the side its coming from, same as O, C1, but that is limited to 5 degrees by alar ligament.
how far can C1 rotatie on each side?
25 degrees of cervical rotation is C1 on C2, but if you add the rest of the cervicals, the rotation is 40 degrees total to each side.
flexion and extension of c1 and c2 is what type of kinematic movement?
mostly translation
during flexion, what happens to the disk between CI and C2
it compresses anteriorly and distracts posteriorly with facets gliding apart.
during extension, what happens to disk
opposite, just like you would expect but the facets approximate and there is compression at inferior margins.
what goes through the transverse foramen?
vertebral artery
what angle are the articular fascets for C3 to C7?
the facets are at 45 degrees with a transverse plane and parallel in frontal plane
what is the joint between the vertebral body of C3 to C7 called?
joint of luschka
when do the joints of luschka form?
they form at age 6-9 and finnish forming at age 18.
what movement do the joints of luschka limit?
lateral flexion is limited to a few degrees
what serves as guide to couple lateral flexion with rotation?
the joints of luschka help with coupled motion
what is the curve of the cervical spine?
lordotic curve of 20 to 50 degrees from C1 to C7
what determines lordotic curve?
facet and disk planes as they develop in response to upright posture.
what is the disk height to body ratio?
2:5. which allows for greater range of motion in cervicals.
what % of cervical curve height is from cervical disks?
25% of the lordotic curve height is from the disc thickness.
which side of cervical disk is higher?
anterior side is higher contributing to a curve.
where is the nucleus pulposus located?
slightly posterior to center.
primary cervical motions?
flexion and extention it does best.
how far can each cervical segment move?
it can flex 15 degrees per segment where the mid cervicals have greatest range at 20 degrees.
what movments are combined to do cervical flex and extend?
movment is a combo of segmental tipping and gliding, so saggital rotation and translation.
when flexing the cervical C3 to C7, what happens?
anterior joint compression etc like would expect, fascets glide apart, one move up on fascet causeing joint gap.
How is extension of C3 to C7 different.
opposite disk movements and the fascets approximate instead of glide apart, and then there is comression at inferior margins of fascets.
averace lateral flexion for each cervical segment?
7-8 degrees decreasing as you move down cervicals.
what movement is lateral flexion of cervical coupled with?
same side axial rotation, think of and airplane turning.
during lateral flexion what happens to facets?
Compress and move medial on side flexing toward, Move a part and laterally on side opposite of flexion.
