Studied by 18 people
force
that which alters the state of rest of a body or its uniform motion in a straight line
direction and magnitude of force
what is the composition of forces?
causes movement in the direction of the force
the effect of the application of a single force applied to a body
equivalent to a single force acting at a common point but with the magnitude equal to the sum of their forces
the effect of two forces acting in the same direction and at a common point
a state of equilibrium
the effects of two equal forces acting at a common point, and in opposite directions
movement in the direction of the greater force
the effect of two unequal forces acting at a common point and in opposite directions
their forces compound producing a desired effect
the effect of two forces acting at an angle to each other
rotation of the body
the effect of two unequal forces acting at different points and in opposite directions
tension
a system of forces tending to separate parts of the body with equal and opposite forces which hold the parts together; used synonymously with force
gravity
the force by which all bodies are attracted to the earth
force of gravity
acts continuously upon the human body, and if unopposed the body will fall to the ground
anti-gravity muscles
erect position is maintained by the integrated contraction of these muscles
center of gravity
the point through which the line of action of the weight acts
the body of the 2nd sacral vertebra
where the center of gravity of the human body is located
line of gravity
a vertical line through the center of gravity
the vertex of the skull, body of the 2nd sacral vertebra, and between the feet
where does the line of gravity of a human pass through?
base of support
the area by which a body is supported
the area between the feet
where is the base support in humans?
stable equilibrium
the body restore to its original position after being displaces
unstable equilibrium
the body tend to displace after application of a force, the body falls on the ground
neutral equilibrium
there is a displacement of the body but the height and position of the center of gravity remain (e.g. a ball moves on a flat surface)
in a lying position
when is the stability of a human greatest?
it becomes less stable as the center of gravity is raised and base of support is reduced
how does the human body become less stable?
kinetics
concentrates on the forces that produce or resist the movement
kinematics
deals with types of motion or movement without regard for the forces that produce motion (type, direction, and quantity of motion)
osteokinematics & arthrokinematics
subdivisions of kinematics
axis
a line about which movement takes place
plane
the surface which a movement takes place
axes & planes
these are used to describe movement
sagittal axis
in an anterior-posterior direction
frontal axis
in the side-to-side direction
vertical axis
is parallel to the line of gravity
horizontal plane
a surface that divides the body into upper and lower
frontal plane
a surface that divides body into anterior and posterior aspect
sagittal plane
a surface that divides the body into right and left
horizontal plane
which plane is trunk rotation performed?
frontal plane
which plane is shoulder adduction performed?
sagittal plane
which plane is shoulder flexion performed?
horizontal plane
which plane is supination-pronation performed?
frontal plane
which plane is hip abduction performed?
sagittal plane
which plane is elbow flexion performed?
sagittal plane
which plane is hip flexion performed?
speed
the rate at which the body moves
velocity
the rate of motion which incorporates direction
work
the product of force and distance
energy
the capacity of a body for doing work
potential energy
the capacity for doing work by virtue of position
kinetic energy
capacity for doing work because of its velocity
power
the rate of doing work or the rate of energy expenditure; (force*distance/time)
joules/second or ergs/second
the unit of power
acceleration
the rate of change in velocity
acceleration
increase in velocity
decceleration
decrease in velocity
momentum
the quantity of motion it possesses
mass x velocity
how do you calculate momentum?
inertia
the resistance of a body to any change in its state of rest or motion; Newton's first law of motion
friction
the force which opposes motion when one surface slides upon another
lever
a rigid bar which is capable of movement about a fixed point called fulcrum
when a force or effort (E) applied at one point in the lever, acts upon another force or weight (W) acting at a second point on the lever (F) - fulcrum
how is work done in a lever?
effort's arm
perpendicular distance from the fulcrum (F) to the effort (E)
weight's arm
perpendicular distance from the fulcrum (F) to the weight (W)
1st class lever
class of lever in which the fulcrum is in the middle of the weight and effort
2nd class lever
class of lever in which the weight is in the middle of the fulcrum and effort
3rd class lever
class of lever in which the effort is in the middle of the fulcrum and weight
example of 1st class lever
example of 2nd class lever
example of 3rd class lever
horizontal/transverse plane
a movement in the vertical axis would occur in which plane?
sagittal plane
a movement in the frontal axis would occur in which sagittal?
frontal plane
a movement in the sagittal axis would occur in which plane?
sagittal plane, frontal axis
which plane and axis does cervical forward flexion occur in?
horizontal/transverse plane, vertical axis
which plane and axis does internal rotation of the shoulder occur in?
horizontal/transverse plane, vertical axis
which plane and axis does circumduction occur in?
sagittal plane, frontal axis
which plane and axis does hip extension occur in?
frontal plane, sagittal axis
which plane and axis does neck lateral flexion occur in?
Note 
Flashcard (40)