Intro Material Flashcards
Define Osteokinematic Motion.
Rotation (as if you are creating part of an arch of a circle around a fixed point). Occurs perpendicular to the plane
Define Arthrokinematic motion.
Motion at the joint surface. it is dependednt on the shape of the joint. The joint will either be Oviod or Steller, and this will influence its movement.
3 types of movement can occure at the articulating surface:
Roll, slide, spine
Define the difference between ovoid and steller
Oviod joints have a convex and a concave portion. For example the glenohumeral joint has a convex humeral head and a concave glenoid fossa.
Steller joints have a combination of convex and concave, as is seen in the interphalangeal joints.
What is the relationship between osteokinematic motion and arthrokinematic motion?
osteokinematic (physiologic) and arthrokinematic (accessory) motions occur simultaneously during movement and are directly proportional to each other, with a small increment of accessory motion resulting in a larger increment of osteokinematic motion.
therefore neither can occur without the other.
How many degrees of freedom are there? explain them?
1: can swing in one direction or only spin
2: A joint that can spin & swing in one way only or it can swing in two completely distinct ways, but not spin
3: can spin and swing in 2 distinct directions
What is the close-packed position?
The position of max congruity of the opposing joint surfaces. it will involve some joint compression as the joints approximate.
What is the open packed position?
It is the position of least joint congruity. It involves an element of joint separation and is the least stable position.
In what position are the ligaments taught? Is fracture/dislocation or sprain/strain more common in that position?
Close-packed the ligaments are taught so fracture/dislocation is more likely.
In an open-packed position (when joints are at the point of least approximation) sprain/strain is more likely.
What factors effect the available joint motion?
Joint integrity (how each bone fits into the other)
elestic energy
passive stiffness (found at the end range of movement)
muscle activation
Factos that effect the bodies ability to with withstand stress
Age
Proteoglycan/collagen content of the tissue
Tissue ability to undergo change
speed at which the adaptive change needs to occue
Define Kinetics.
The study of forces created as motion changes
Define Mass.
The quantity of matter composing a body
Define inertia.
The resistance to action or to change
define center of gravity.
a point around which the weight and mass are aqually balanced in all diecions.
Define force.
A vectory quantity with magnitude, direction and point of application to a body
define Load
the type of force applied
Define Stress.
The forece per unit area that occures on the cross section of a structure in responce to an externally applied load
Define strain
the deformation that occurs within a structure in responce to externally applied loads
