Biomechanics test Flashcards
Gravity (Stability)
Force that exerts a downward pull on people + objects
Center of gravity (stability)
An imaginary concentrated balance point. Intersection of 3 planes
Line of gravity (stability)
A line passing straight down through the center of gravity to the ground
Base of support (stability)
The area bounded by the supporting limbs and the space between them
mass (stability)
A measure of resistance to linear motion. greater mass = greater resistance to motion
States of Motion (stability)
Motionless, angular, linear
Force (max effort)
Push or pull that causes motion, usually measured in newtons
velocity (max effort)
the measure of how fast the body moves. measured in m per second (v=d/t)
Acceleration (max effort)
the rate of change of velocity (a=v2-v1/t)
Newtons 1st law
Every body will remain in a constant motion or rest unless acted on by an outside force
Newtons 2nd law
The applied force is proportional to the resulting acceleration (greater applied force= greater acceleration)
Newtons 3rd law
For every action force, there’s an equal and opposite reaction force
Momentum (linear motion)
A strength or force gained by motion or by a series of events (M x V)
Impulse (linear motion)
A certain amount of force you apply for a certain amount of time to cause a change in momentum (I = force x length of time x forces applied)
Joint range of motion (linear motion)
The extent or limit to which a part of the body can be moved around a joint or a fixed point (measured in degrees)
Streamlining (linear motion)
The contouring of an object, to reduce its drag or resistance to motion through a stream of air
Angular motion
The motion of a body about a fixed point or axis (ex. Gymnast around a bar)
Angular velocity (angular motion)
Rotational velocity of an athlete performing angular motion
Torque (angular motion)
The tendency of a body to rotate about an axis of rotation (t= force x distance from axis of rotation)
Moment of inertia
Measure of resistance to angular motion (i= mass x distance from axis) Ex. bring arms in on figure skating turn
Angular momentum
Angular motion of linear momentum ( moi x angular velocity)
Principle #1
The lower the centre of gravity, the larger the base of support, the closer the line of gravity to the centre of the base of support, and the greater the mass, the more stability increases.
Principle #2
The production of maximum force requires the use of all joints that can be used
Principle #3
The production of maximum velocity requires the use of joints in order from largest to smallest
Principle #4
The greater the applied impulse, then greater the increase in velocity
Principle #5
Movement usually occurs in the direction opposite that of the applied force
Principle #6
Angular motion is produced by the application of a force acting at some distance from an axis, that is, by a torque
Principle #7
Angular momentum is constant when an athlete or object is free in the air
