Biomechanics

Law 1

An object will remain at rest or in motion unless acted upon by an external force

Law 2

Force equals mass times acceleration

Law 3

Every action has an equal and opposite reaction

Biomechanics

Physics of human movement

Balance

Maintaining stability when stationary or moving

Factors of Balance

Centre of gravity, line of gravity, base of support, mass of body

Base of support (BOS)

Contact with the base of the surface

Centre of gravity (COG)

Object is equally balanced at the center of mass, in middle of body area

Line of gravity (LOG)

Theoretical line from the center of gravity to the base of support, COG down

Mass of body

Increasing mass increases stability

Stability

Resistance to being moved, dependent on factors like center of mass, friction, rotation, mass, and leaning into forces

Force

push or pull

Motion

movement

Levers

Mechanical devices that amplify force around a fixed point (axis) to move a resistance force

load (resistance)

mechanical variable to describe force

fulcrum (axis)

fixed point of support of lever, for pivot

effort (force)

energy consumption through force

1st class lever

fulcrum in the middle (see-saw)

2nd class lever

load is in the middle (wheelbarrow)

3rd class lever

force is in the middle (bicep curl)

balance

coordination and control

factors effecting lever

amount of force, inertia and length

linear motion

movement of body along straight or curved path

distance

path from start to finish

displacement

change of position + direction

speed

time taken to cover distance (linear)

velocity

time taken to change position (angular)

acceleration

change in speed or velocity in given time period

momentum

mass x veloctiy, amount of motion an object has

angular momentum

momentum possessed by rotating object (closer = faster)

force summatiomn

sequence of body parts timed moving (heavier first)

longer lever

more power and momentum from extended length