Introduction to Kinesiology Flashcards
Kinematics
Study of movement related to displacement, velocity & acceleration
Velocity
Change in distance/change in time
Acceleration
Change in velocity/change in time
Kinetics
Movements in terms of force
Impulse and Momentum
Forces applied over a period of time
Work and Energy
Forces applied over distance
Force
Mass x acceleration
Vector
Forces that act on a lever
Vector Characteristics
Magnitude
Direction
Point of application
Line of application
Force Types
Gravity
Shear
Tensile
Compressive
Gravity
Always vertically down
Mass x gravital acceleration
Shear
Coplanar, in opposite direction
blister
Tensile
Colinear, in opposite direction
ligament strain
Compressive
Colinear, in similar directions push together
meniscus
Newton’s First Law
Inertia - Equilibrium
Body at rest will stay at rest
Newton’s Second Law
Acceleration
Particle subjected to resultant force will accelerate in direction of force and magnitude of acceleration will be proportional to force of magnitude
Newton’s Third Law
Action/Reaction
For every action, there is an equal and opposite reaction
Moment (Torque)
Application of force at a distance from pivot point that cause rotation around a stationary point
Force x Distance
Levers
Increase or decrease mechanical advantage
Mechanical Advantage
Force arm divided resistance arm
First Class Lever
FAR
Seesaw
Second Class Lever
ARF
Wheelbarrow
Third Class Lever
AFR
Tweezers
Pulley
Improve line of pull or mechanical advantage
Could be fixed or movable
Fixed Pulley
MA=1
Pulley wheel only rotates
Movable Pulley
MA=2
Pulley rotates and translated
1 pulley = 1/2 force
2 pulleys = 1/4 force
Cams
Non-uniform ellipses used to increase MA
Allows for variable resistance to match the length-tension relationship