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