Arthrokinematics Flashcards
Osteokinematics Physiologic motion
describes the motion between two or more bones that occur in the three cardinal planes
Arthorkinematic motion
describes the motion that occurs between/ among joint articular surfaces
3 cardinal planes
- coronal
- transverse
- sagittal
coronal
anteriorposterior axis
transverse
longitudinal axis
sagittal
mediolateral axis
Joint Axis run:
orthogonal or perpendicular to the planes of motion
Common motions in
Sagittal plane
flexion/ extension
dorsiflexsion & plantar flexion
forward & backward bending
Frontal Plane
abduction / adductions
lateral flexion
ulnar & radial deviation
eversion/ inversion
transverse
internal and external rotation
axial rotation
degrees of flexion
refers to the number of independent directions of movement allowed for the joint
maximum degrees of freedom
3 degrees of freedom that corresponds to the 3 cardinal planes
arthorkinematics
describes the motion that occurs between the joint articular surfaces
arthrokinematics can be:
active or passive
active is
by muscle contraction
passive is
by tension in adjacent connective tissue or natural joint laxity, thus accompany physiologic motions
shape of joint
dictates arthro motion at a particular joint
these shapes can be
convex or concave
the convex-concave relationship
- improves joint congruency
- increases contact surface area for distributing forces
- helps quid motion between bones
2 things you need to know to predict arthro behavior
- which surface is movable and which is fixed
2. which surface is concave and which is convexed
Fundamental movements between joint surfaces
- roll (rock)
- glide (slide)
- spin
Roll
Rock
describes when MULTIPLE points along one articular surface contacts MULTIPLE points on another surface
ex: tire rotating across surface
Glide
Slide
describes when a SINGLE point on one surface contacts MULTIPLE points on another surface
ex: tire skidding across surface
Spin
pure spin describes when a SINGLE point on one surface rotates on a SINGLE point on another surface
ex: spinning top
ex: radius spins against capitulum of the humerus during pronation
classic combo of all three
flexion and extension of the knee
arthro principles of movement are based on :
the roll and glide of reciprocally concave/convex surfaces
movable surface is convex
roll occurs in direction of physiologic motion
glide occurs in the opposite direction
moveable surface is concave
roll & glide occur in the same direction of the physiologic motion
spin
can occur when either concave or convex surface is movable
occurs along the axis of movable bone
where the longitudinal axis of the movable axis of long bone intersects the surface of its articular mate at right angles
distal-on-proximal segment kinematics
OPEN kinetic chain
Open kinetic chain refers to
distal-on-proximal
distal segment is NOT fixed to the earth and is free to move
if you know the natural behavior of the articular surface of a given synovial joint you can:
take advantage of the accessory movements allowed at those joints and apply an external force on one surface in a deliberate direction to facilitate motion at that joint
accessory movements:
“joint play”
are slight passive translator movements that occur in most joints
the capacity for joint motion depends on:
the position of the joint
each synovial join has a position of
maximal joint congruency
closed-packed position
reinforcing ligaments and reinforcing portions of the joint capsule are taut
thus rendering the joint in its naturally most stable position
closed-packed is typically when:
the joint is near or in the very end range of motion
open-packed or loose-packed
is described as any other position than the joint’s closed-packed position
loose-packed
ligaments and capsules are relatively slack and allow for increase in accessory motion at the joint
proximal-on-distal kinetic chain
CLOSED kinetic chain
describes a situation in which the distal segment of the kinematic chain is fixed to the earth or another immovable object
