Biomechanics Final Flashcards
What are the three points in space that determine plane?
- sagittal
- frontal (coronal)
- transverse (axial)
What is a flat surface determined by the position of three points in space?
Plane
What type of motion is motion in which all points of a rigid body move parallel to a fixed plane (two dimensional movement)?
Plane motion
Which motions are occurring in the sagittal plane?
- flexion
- extension
Which motions are occurring in the frontal (coronal) plane?
- right lateral flexion
- left lateral flexion
Which motion is occurring in the transverse (axial) plane?
-rotation
Which type of motion is motion in which all points of a rigid body do not move in a single plane (3 dimensional movement)
Out of plane motion
What is a line around which rotary movement takes place or along which translation occurs?
Axis
Which direction would a line run if it were in the X-axis?
a line passing horizontally from side to side
The X-axis is referred to as the “_______” or “_______” axis.
“frontal” or “coronal”
Movement around the X-axis is in which plane?
the sagittal plane
The Y-axis is a line that runs…
perpendicular to the ground
The Y-axis is referred to as the “_______” or “________” axis.
“longitudinal” or “vertical”
Movement around the Y-axis is in the…
transverse or axial plane
The Z-axis is a line passing…..
horizontally back to front
The Z-axis is referred to as the “______” axis
“sagittal”
Movement around the Z-axis is in the….
frontal or coronal plane
What are the number of ways in which a body can move (for example: one degree of freedom would be translation or rotation about one axis) termed?
Degrees of freedom
Spinal segments exhibit 6 degrees of freedom, those six degrees of freedom are what?
- 3 translations
- 3 rotations
When a rigid body moves in a plane, at every instant there is a point in the body or some hypothetical extension of it that does not move; what term is being described?
Instantaneous Axis of Rotation (IAR)
An axis perpendicular to the plane of motion and passing through that point is the what for that motion, at that instant?
instantaneous axis (center) of rotation (IAR)
Which term is used to describe any vertebral motion in a two dimensional plane?
IAR
As different force vectors are applied to a vertebra, they may cause a shift in the IAR which will dictate what for that motion segment?
the pattern of deformation
T/F: The IAR is different for cervical, thoracic, and lumbar spinal segments but remains the same under changing loads.
FALSE!!! The IAR is different for cervical, thoracic, and lumbar spinal segments and is different under changing loads
What is the functional unit of the spine and has the following characteristics?
• smallest spinal segment exhibiting biomechanical characteristics similar to those of the entire spine
• two adjacent vertebrae and their interconnecting disc, joints, capsule and ligaments
• six degrees of freedom
Motion segment
What is an important ligament in motion segment?
Capsular ligament
What are 3 articulations that are important in motion segment?
- Joint space of the zygapophyseal joint
- Capsule of the zygapophyseal joint
- Superior articular facets
What type of motion is consistent association of one motion (translation or rotation) about one axis with another motion about a second axis
Additionally:
• one motion cannot be produced without the other
• two motions occurring at the same time along two different axes
Coupled motion
What type of joint position is described by the following?
• joint capsule and ligaments are most relaxed
• maximum joint play is possible
• articulating surfaces are maximally separated
• position used for traction or joint mobilization
Loose-packed joint position
What is the facet joint loose-packed position?
half way between flexion and tension
What joint position is described by the following?
• the capsule and ligaments maximally tightened
• there is no joint play
• there is maximal contact between the articular surfaces
Closed-packed joint position
What is the facet joint closed-packed position?
extension
Which portion of the occiput has the following characteristics?
- face laterally and inferiorly
- form convex rockers
- sit in concave surface of superior articular facet of C1
Condyles
Which part of the atlas (C1) has the following characteristics?
- concave surface
- face medially and superiorly
- compliment condyles
- allow occipital condyles to rock
Superior articular facets
In CO-C1 Flexion and Extension, occiput glides _______ (flexion) and rolls _______ (extension)?
posteriorly; anteriorly
The greatest range of motion in CO-C, excursion is __° _____ to __° _____.
10° flexion; 25°extension
In CO-C1 Lateral Flexion, occiput rolls on side of ______ ______ and glides on which side? What is the range of motion on each side?
lateral flexion; on opposite side
range of motion 5°each side (minimal)
In CO-C1 Rotation, occiput glides ______ on side of rotation and ________ on side opposite rotation.
posteriorly; anteriorly
CO-C1 rotation is limited by which ligament?
alar ligament
What is the range of motion for CO-C1 rotation?
5°each side (minimal)
The C1-C2 (Atlas-Axis) joint consists of which 3 joint types?
two facet joints plus the atlas-odontoid joint
The planes of facet joints of C1-C2 are mostly _______.
horizontal
The inferior facets of C1 are slightly _______ and face which direction?
convex; inferior and medially
The superior facets of C2 are slightly ______ and face which direction?
convex; superiorly and laterally
What is the synovial joint between odontoid and anterior arch of atlas (C1)?
Atlas-odontoid joint
Which ligament courses around posterior aspect of odontoid?
transverse ligament
With C1-C2 Flexion and Extension, in flexion, C1 articular surfaces glide ________ (minimal) and in extension, C1 articular surfaces glide ________ (minimal)
posteriorly; anteriorly
C1-C2 Lateral Flexion has limited active range of motion, what is the degree of motion?
5°each side (minimal)
Articular surfaces of C1 glide (translate) on articular surfaces of C2 toward which side?
the side of lateral flexion
T/F: C1-C2 Rotation is very mobile in rotation and accounts for approximately half of cervical rotation.
True
C1 rotates around odontoid in which plane?
horizontal plane
C1 articular surface glides _______ on the side of rotation and _______ on the side opposite rotation.
posterior; anterior
In C1-C2 rotation, range of motion averages __° each side; the first __°of cervical rotation occur exclusively at C1-C2.
40°; 25°
C1 pivots around which axis in center of odontoid?
vertical
C2 Flexion-Extension is primarily _____
translation
In C1-C2 flexion/extension which do the following characteristics describe?
- anterior disc compression … posterior distraction
- facets glide apart producing stretching and joint gapping
Flexion
In C1-C2 flexion/extension which do the following characteristics describe?
- anterior disc distraction … posterior compression
- facets approximate … compression at inferior margins
extension
T/F: In lower cervical biomechanics (C3-C7), the design is consistent from C3 to C7
True
T/F: In lower cervical biomechanics (C3-C7) the vertebral body wider A-P than transversely
FALSE!!! In lower cervical biomechanics (C3-C7) the vertebral body wider transversely than A-P
What is the purpose of the transverse foramen in C3-C7?
Opening for the vertebral artery
In lower cervical biomechanics (C3-C7) articular facets are a _____°angle with the transverse (horizontal) plane.
45°
In lower cervical biomechanics, articular facets are ______ in frontal (coronal) plane and the articular surface is nearly flat.
parallel
In lower cervical biomechanics (C3-C7) what is the term for interbody joints or uncovertebral joints?
Joints of Luschka
At what age do the Joints of Luschka form? What age are they complete?
Form age 6-9 and are completed by age 18
What is a minor purpose of the Joints of Lushka?
limit lateral flexion to only a few degrees
The Joints of Lushka serve as guides to couple which type of flexion with which other motion (coupled motion)?
lateral flexion; rotation
Which curve is a lordotic curve of 20°-50° (average is 45°) that begins C1 and extends to C7?
Cervical Curve
T/F: Facet and disc planes determine cervical curve and secondary cervical curve develops in response to upright posture
True
T/F: Cervical Disc (C3-C7), disc height-to-body height ratio 2:5 … allows for greater ROM in cervicals
True
What constitutes 25% of height of cervical curve?
Cervical discs
Cervical discs are higher anteriorly which contributes to what form of the cervicals?
cervical lordosis
The nucleus pulposus slightly ______ to center
posterior
In lower cervical flexion and extension (C3-C7), flexion and extension predominate over other motions; the average range of motion is __° per segment for combined flexion-extension.
15°
Which area of cervicals have the greatest range in flexion-extension at 20°?
Mid cervicals
Which areas have the lowest cervical range for flexion-extension is C_-C_ and C_-T_ at 10°?
C2-C3 and C7-T1
Lower cervical flexion/extension movement is combination of segmental tipping (sagittal ______) and gliding (sagittal ______).
rotation; translation
With lower cervical flexion-extension (C3-C7), which motion has the following characteristics?
- anterior disc compression … posterior distraction
- facets glide apart producing stretching and joint gapping
flexion
With lower cervical flexion-extension (C3-C7), which motion has the following characteristics?
- anterior disc distraction … posterior compression
- facets approximate … compression at inferior margins
extension
With lower cervical lateral flexion (C3-C7) what is the average lateral flexion range to each side?
range is 7°-8°
True/False: With lower cervical lateral flexion (C3-C7), lateral flexion increases as move caudally down cervical spine.
FALSE!! With lower cervical lateral flexion (C3-C7), lateral flexion DECREASES as move caudally down cervical spine
With lower cervical lateral flexion (C3-C7) (coupled motion), lateral flexion is coupled with which type of rotation?
ipsilateral axial rotation
True/False: With lower cervical lateral flexion (C3-C7), the degree of coupled rotation decreases in a cephalic to caudal direction
True
With lower cervical lateral flexion (C3-C7), lateral disc wedging and approximation are present on the side of ______ ______ and distraction is present where?
lateral flexion; on the side opposite lateral flexion
With lower cervical lateral flexion (C3-C7), the inferior facet glides _____ and _____ on the side of lateral flexion and ____ and ___________ on the side opposite lateral flexion.
down and medially; up and laterally
With lower cervical rotation (C3-C7) what is the average rotation range of motion to each side?
range of motion is 5°
With lower cervical rotation (C3-C7), rotation decreases significantly at which vertebral segment? What is the average rotation at this segment?
C7-T1; average rotation is 2°
With lower cervical rotation (C3-C7), there is predominantly which type of rotation coupled with which type of flexion?
axial rotation; ipsilateral lateral flexion
With lower cervical rotation (C3-C7), the vertebral bodies lateral flex to which side?
to the side of rotation
True/False: With lower cervical rotation (C3-C7), the coupling is not as strong as that noted with cervical lateral flexion.
True
With lower cervical rotation (C3-C7), on the side of rotation the inferior facet glides which two directions? And on the side opposite rotation the inferior facet glides which two directions?
down and medially; up and laterally
With typical thoracic biomechanics (T2-T8), what are the characteristics of transverse processes? Spinous processes?
transverse processes are thick, strong and long; spinous processes are long and slender
With typical thoracic biomechanics (T2-T8), where are costovertebral joints located? And with what do they articulate?
on side of vertebral body articulate with rib heads
With typical thoracic biomechanics (T2-T8), where are the costotransverse joints located? And with what do they articulate?
on transverse process articulate with tubercles of ribs
With typical thoracic biomechanics (T2-T8), articular facets form a __° angle from the transverse toward which plane and a __° angle from the coronal toward which plane?
60° angle; coronal plane; 20° angle; sagittal plane
With typical thoracic biomechanics (T2-T8), inferior facets face which 3 directions? Superior facets face which 3 directions?
Inferior: inferiorly, medially and anteriorly
Superior: superiorly, laterally and posteriorly
What are the atypical thoracic vertebrae? (T1 and T9-T12)
T1 and T9-T12
With atypical thoracic vertebrae, T1 resembles which cervical vertebra? What is another characteristic specific to T1 relating to the ribs?
C7; has a whole facet for articulation with the first rib
With atypical thoracic vertebrae, T9-T12 have what atypical characteristics?
variations on the location of the facets on the body and transverse process for articulation with the ribs
With atypical thoracic vertebrae, T11 and T12 begin to take on which type of characteristics?
begin to take on the characteristics of a lumbar vertebra
With the thoracic curve, what is the kyphotic curve degree range and average?
20°-50° (average is 45°)
With the thoracic curve, where does it begin? What does it extend to?
T1-T2 and extends to T12
With the thoracic curve, where is the apex located?
T6-T7 disc space
With the thoracic curve, when is the primary curve developed?
at birth
With the thoracic curve, flattening of thoracic curve will cause which 3 curvature changes?
- cervical curve to decrease
- cervical curve to shift forward
- lumbar curve to increase
True/False: With thoracic disc, the disc height-to-body height ratio 1:5, which is the smallest ratio in the spine; this contributes to decreased flexibility in the thoracic spine.
True
Within the thoracic disc, what is the location of the nucleus pulposus?
located centrally within annulus
In thoracic flexion and extension, thoracic segment combined flexion-extension averages _°. What are the degrees for the following areas?
_° in upper thoracics, _° in middle thoracics, __° in lower thoracics
6°; 4° in upper thoracics, 6° in middle thoracics, 12° in lower thoracics
Thoracic flexion and extension combines which sagittal plane motion with slight sagittal plane translation (minimal).
rotation;
Which thoracic movement has articular facets that glide apart as the disc opens posteriorly?
flexion
Which thoracic movement has facet joints and posterior discs that approximate?
extension
In thoracic lateral flexion (coupled motion), what is the average degree movement to each side?
averages approximately 6° to each side
In thoracic lateral flexion (coupled motion), upper thoracic lateral flexion is coupled with which type of rotation?
axial rotation
Upper thoracic lateral flexion and rotation occur to the same side, body rotation to the _______ and spinous deviation to the ________.
concavity; convexity
True/False: In the middle and lower thoracics coupling may occur in either direction.
True
In thoracic lateral flexion, the disc and facet joint approximate on the side of ______ flexion and separate on the side _______ ______ flexion.
lateral; opposite lateral
Upper thoracic inferior articular facets glide which direction on the side of lateral flexion and which direction on the side opposite lateral flexion due to what?
medially; laterally; strong coupled axial rotation
With thoracic rotation, upper thoracic average rotation is °-° to each side. Rotation decreases in ______ thoracics and is minimal in ______ thoracics.
8°-9°; middle; lower
Upper thoracic rotation is coupled with which type of lateral flexion?
same-side
In thoracic rotation, inferior facets glide which direction on same side of rotation and glide which direction on the side opposite rotation?
inferiorly; superiorly
With rib motions, “Pump Handle Action” (T1-T6), with inspiration, ribs associated with T1-T6 are pulled in which 2 directions?
up and forward
With rib motions, the pump handle movement increases the _____ diameter of the rib cage. The rib head rolls _________, elevating the anterior end of the rib like the handle of a pump
A-P; downward
With rib motions, “Bucket Handle Action” (T7-T10), with inspiration, ribs T7-T10 are moved in which 2 directions?
elevated and depressed
With rib motions, bucket handle movement increases the ______ diameter of the rib cage. The ribs ride in which 2 directions on the transverse process while the rib elevation and depression simulates a bucket handle moving on its hinges.
transverse; up and down
With rib motions, “Caliper Action” (T8-T12), with inspiration, ribs T8-T12 move in which direction? Caliper movement increases the _______ diameter of the rib cage.
laterally; lateral
With lumbar biomechanics (L1-L5), what are the characteristics of the pedicles and laminae? Spinous processes? Transverse processes?
- pedicles and laminae are short, broad and strong;
- spinous processes are thick and broad
- transverse processes are long, slender and flattened on their anterior and posterior surfaces
With lumbar biomechanics (L1-L5), articular facets primarily in which plane but become more ________ at the lumbosacral junction.
sagittal; coronal
With lumbar biomechanics, greatest mobility is in which 2 movements? Why?
flexion-extension; facet orientation limits rotational flexibility
With lumbar curve, what is the degree of lordotic curve, including the average?
20°-60° (average is 35°)
Where does lumbar curve begin? Where does it extend? Where is the apex?
L1-L2 and extends to sacrum; apex is at L3-L4
What type of curve is the lumbar curve and how does it develop?
Secondary curve; develops in response to standing
With lumbar curve, anterior pelvic tilt ________ lordosis, posterior pelvic tilt ________ lordosis
increases; decreases
True/False: The lumbar disc height-to-body height ratio is 1:3 and allows ROM.
True
Within the lumbars, where is the nucleus pulposus located? What two things does this allow for?
posteriorly within annulus
• allows for movement
• resists axial compression forces
Compression force from body weight and muscle contraction raises _________ pressure in the nucleus pulposus.
hydrostatic
Increased tension in the annulus inhibits what of the nucleus?
radial expansion
Increased nuclear pressure is exerted upward and downward against what?
the endplates
True/False: Increased pressure elevates tension in the annular fibrosus. Pressure within the nucleus reinforces the peripheral annulus fibrosus creating a stable weight-bearing structure.
True
What is a shallow generalized extension of the disc tissues beyond the edges of the vertebral body (<3mm)?
Disc Bulge
What condition do the following characteristics describe?
- annual fibers buckle outward
- may compress neural tissues in the IVF or spinal canal
- pain
- joint dysfunction
Disc bulge
True/False: A disc bulge is a herniation.
FALSE!! It is NOT a herniation!
What term describes a symmetrical presence of disc tissue “circumferentially” beyond the edges of the vertebral body?
“Bulging disc”
True/False: “Bulging” is a descriptive term for the shape of the disc and is not diagnostic
True
Asymmetrical bulging of the disc margin, is found in which condition?
severe scoliosis
What do the following characteristics describe?
• disc material ruptures through the annular fibers
• may compress nerve in IVF
• may cause radicular pain
• intense inflammatory response
• torn annular fibers cause somatic pain
Disc Herniation
What is a localized displacement of disc material beyond the limits of the intervertebral disc space? This is “localized” process involving less than 50% (180°) of the disc circumference.
Disc Herniation
Which type of herniation involves less than 25% (90°) of the disc circumference?
Focal” Herniation
Which type of herniation involves between 25% and 50% (90-180°) of the disc circumference?
“Broad-based” Herniation
True/False: Herniated discs may take the form of protrusion or extrusion, based on the shape of the displaced material.
True
What is the term for when the base of the herniation is broader than the distance it protrudes into the spinal canal?
Protrusion
What is the term for when the disc material balloons into the canal with a comparatively narrow base, as if trying to bud off and may become sequestered?
Extrusion
What do the following characteristics describe?
• radial, transverse or concentric tears (fissures) in the annulus
• may weaken the disc
• may generate pain
• disc material may migrate into the tears
Annular Tears
What is the lumbar segment combined flexion-extension averages?
15°
True/False: Lumbar flexion and extension combines sagittal plane rotation with slight sagittal plane translation (minimal).
True
With lumbar flexion, the vertebra tilts and slides _______, facets glide ________, and disc is compressed ______ and stretched ________.
anteriorly; superiorly
anteriorly; posteriorly
With lumber extension, the vertebra tilts _______. Facets approximate, facet capsule, disc, and anterior longitudinal ligament are stretched _______.
posteriorly; anteriorly
With lumbar lateral flexion, what is the average degree movement to each side? What about the lumbosacral joint?
averages approximately 6° to each side
the lumbosacral joint has only about 3°of lateral flexion
True/False: Lumbar lateral flexion is coupled with same side rotation, facets on side of lateral flexion glide together, and facets on side opposite lateral flexion glide apart.
FALSE!!!: Lumbar lateral flexion is coupled with OPPOSITE side rotation, facets on side of lateral flexion glide together, and facets on side opposite lateral flexion glide apart.
Lumbar Right lateral flexion have what 2 characteristics of movement?
- facets on right glide together
* facets on left glide apart
Lumbar lateral flexion is coupled with opposite side rotation, which is body rotation to the ________ and spinous deviation to the _______. This is opposite of the coupled motion in the cervical and upper thoracic spine.
convexity; concavity
