therapeutic exercise considerations

center of gravity

the point mass of a body or segment

true

the COG changes w motion and with weight

t ro f

false

the COP changes w motion and with weight

t ro f

true

the lower the COG is the more stable an object is

t or f

false

the higher the COG is the more stable an object is

t or f

base of support

the 2D area between and including the object’s point of contact in the supporting surface

wider

a ____ BOS means increased stability

narrow

a ___ BOS indicates a decreased stability

stability

occurs when the lone of gravity falling within the base of support

lateral

with a wide BOS means a ____ perturbation has a dec chance of falls

anterior/posterior

with a narrow BOS means a ____ perturbation has a dec chance of falls

lever

a simple machine that contains a rigid bar and a fulcrum

first class

a ____ lever has the fulcrum between the resistance and force arms

second class

the ____ lever has the resistance point between the fulcrum and the force arm

third class

the _____ lever has the force point between the fulcrum and the resistance arm

true

this is an example of a first class lever

t or f

false

this is an example of a second class lever

t or f

true

this is an example of a second class lever

t or f

false

this is an example of a third class lever

t or f

true

this is an example of a third class lever

t or f

false

this is an example of a second class lever

t or f

true

in a lever when speed of motion increases then the ROM and forces decreases

t or f

false

in a lever when speed of motion increases then the ROM and forces increases

t or f

linear motion

occurs with a straight line movement from a force

angular motion

occurs with a rotational movement from a force

torque

a product of force and the force arm length during angular motion

moment arm

the lever arm or force arm is the ______ or the distance from the fulcrum to the force vector

line of pull

the long axis of the muscle or the direction along which a muscle exerts a force going along origin to insertion

angle of pull

the angle between the muscle line of pull and long axis bone

true

the angle of pull and moment arm change w joint motion

t or f

false

the line of pull and moment arm change w joint motion

t or f

true

maximum rotation force occurs at 90 deg

t or f

false

maximum rotation force occurs at 45 deg

t or f

true

when muscle lengths decrease the max tension of the muscle decreases

t or f

false

when muscle lengths decrease the max tension of the muscle increases

t or f

summation of forces

a sequence of movements timed so each contributes to the next movement to make a desired outcome

strength

ability to resist or make a force

work

the force x time over it is applied

power

work produced divided by time

energy

the capcity to do work

velocity

the rate of change in an object’s position

acceleration

the rate of change of which velocity increases

elasticity

the object’s ability to return to normal size/shape after a deforming force is applied

elastic limit

the point of the object’s ability to return to normal shape and size before having plastic changes

yield point

the tissue’s point where deformation starts to occur and leads to tissue damage

stiffness

the ability to resist deformation when stress is applied

strain

the change in an object when a stress is applied

stress

the force that is applied to a tissue over time

creep

the permanent tissue elongation in response to a low level stress applied over time

structural fatigue

continuously applying a force causing fatigue overtime leading to eventual breaking or failure from continous weakening

friction

the resistance to a movement from 2 different surfaces