Kinesiology
Study of movement
Biomechanics
Study of living organisms by means of mechanical principles
Aristotle
One of the first to study human movement and animal movement
Leonardo da Vinci
Artist but primarily engineer
Studied mechanics for human movement
Invented water skis and hang gliders
Andreas Vesalius
Published de humani corporis fabrica which was the first modern human anatomy text
Boreal I
First to apply concepts of levers and forces to skeletal bodies
Wrote a book that also had information about bird migration
Sir Isaac Newton
Father of mechanics
Gravity, three laws of motion
Modern math
2nd most influential person in history
James Marey
First instrumented biomechanics laboratories
Archibald Hill
Mechanics of spring
Statics
Analysis of loads in static equilibrium; objects at rest or constant velocity
Dynamics
Analysis of loads subject to accelerations or not at a steady state; objects in motion
Kinematics
Description of motion (speed, velocity)
Kinetics
Causes of motion (force)
Scalars
Magnitude and units
Speed
Vectors
Magnitude and direction
Velocity
Includes arrows
Branches of mechanics
Rigid body
Deformable body
Fluid mechanics
Quantum mechanics
1 meter=
=39 inches
1 kg =
= 2.2 lbs
Inertia
Property of an object to resist changes in motion
Analog signal
Continuous signal
Electrical output
Digital signal
Computer signal 1 and 0s
Easier to store, takes up less room
Does not get as much info and is less accurate
Sampling rate
How often an instrument records measurement
Photocells
Laser between 2 sensors
Timing mat
Feel a force has starts or stops time
Timing chips
Cross a line and chip starts or stops time
Velocity measurement systems
Radar gun
Laser systems
Electromyography
Determines if muscles are moving
Modeling
Mathematical representation of bio mechanical system
Forces
Simply a push or pull
Action and reaction
Force units
1 Newton = 1 kg*1m/s^2
Weight equation
W = mass*g
Newtons
Gravity constant
9.81 m/s^2
Components of contact forces
Normal or perpendicular
Parallel (friction)
Static friction
Object doesn’t move
Highest COF
Dynamic friction
Object is moving
Friction
Force produced by the interaction of the particles between two objects
Ways to change friction
Change a surface
Change surface area
Rolling friction
Lower than static and kinetic friction
Qualities of forces
Point of application Line of action Magnitude Frequency Rate
Collinear
Same line of application of force
Added algebraically
Static equilibrium
Net force acting on an object is zero
Sum of forces = 0
Free body diagram
Drawing showing the external forces acting on a system
Types of motion
Rectilinear
Curvilinear
Angular
Rectilinear
Type of motion
Motion in a straight line
Curvilinear
Type of motion
Rotating around something
Linear motion
Change in position with respect to reference frame
Speed
Scalar
S=l/t
L = distance
Velocity
Vector
V = d/t
D= displacement
External forces affecting motion
Weight
Friction
GRF
Contact forces
1st law of motion
Law of inertia
Body at rest will stay at rest and a body in motion will stay in motion unless acted on by an outside force
Momentum
Quantity of motion
Vector
L = m*v
Types of collisions
Elastic
Inelastic
Coefficient of restitution
Ratio of velocities in a collision
Measure of elasticity
Factors affect COR
Material
Temperature
Altitude
2nd law of motion
Law of acceleration
Change in motion of an object is proportional to the force exerted and is made in the direction of the force
Impulse
Effect of force acting over time
Vector
J=f*t
Produces a change in momentum
3rd law of motion
For every action, there is an equal and opposite reaction
Work
Capacity of a force to cause displacement
Power
Rate of doing work
Work equation
W =force * distance
Joules or Newton meters
Power equation
P= force*displacement/time
Watts (J/s)
Most effective power training
<70% of 1RM
Measure of power
Direct
Indirect
Direct measures of power
Margaria test
Vertical jump
Broad jump
Indirect measures of power
Olympic weightlifting
Energy
Capacity to do work
Joules
Scalar
Mechanical energy
Ability to do work
Kinetic energy
Type of energy Associated with motion of an object
Gravitational potential energy
Type of energy associated with height of object
1st law of thermodynamics
Energy is neither created nor destroyed
Law of conservation of energy
2nd law of thermodynamics
Cannot finish any real physical process with as much useful energy as you had to start with
Some energy is always wastes, never 100% efficient