Fall review for quiz 1 Flashcards
in what direction does the roll occur in arthrokinematic movements?
in the direction of osteokinematic movement
in what direction does the slide/glide occur in arthrokinematic movements?
direction of motion, dependent on joint structure
when a concave articular surface moves on a relatively stationary convex surface roll and slide occur in…
same direction
when a convex surface moving on a concave surface roll and slide occur in…
opposite direction
for open chain tasks eyes should look at ________ segment to determine the roll
distal
for closed chain tasks eyes should look at ___________ segment of the joint to determine the roll
proximal
define moment arm
the perpendicular distance from the line of action to the axis of rotation
define rotary arm
the perpendicular distance from the point of application on a lever
define a lever arm
distance from the point of application of the force to the axis of rotation
what is creep?
when load is suddenly applied and then held constant overtime, continued deformation over time though load is held constant
what is stress relaxation?
deformation held constant, force required to maintain a deformation decreases over time
what is a vector component?
goes in the force of muscle fiber orientation, always parallel to the lever from the POA
what is a compression component?
the vector goes into the joint or POA is superior to joint
what is a tension component?
the vector goes away from the joint or POA is inferior to joint
what is a rotary component?
torque always perpendicular at the POA
POA
point of application; location where the force is applied
LOA
line of action; direction and angle of the force
define magnitude
length of vector
what is an open kinematic chain?
distal joint segment is free to move while proximal segment provides stability