Biomechanical Principles Flashcards
Define biomechanics?
The study of human movement and the effect of force and motion on performance.
What things can biomechanics allow us to do?
- Maximise efficiency of performance
- Analyse performance
- Reduce acute injuries
- Design protective and comfortable equipment.
Define motion?
The principle of something moving.
Newton’s 1st Law?
INERTIA- a body will remain in a state of rest (stationary),until acted on by an external or unbalanced force.
Sporting Example?
Newton’s 2nd Law?
ACCELERATION- a bodies rate of change of momentum is proportional to the force applied to it and acts in the same direction.
Sporting Example?
Newton’s 3rd Law?
REACTION- for every action force applied to a body there is an equal and opposite reaction force.
Sporting Example?
Define reaction force?
A force acting within Newton’s 3rd law that opposes the action force. When one object pushes against another.
Define velocity?
The rate of change of displacement.
What’s the equation for velocity?
Velocity= distance (m) =m/s
time (s)
Define momentum?
The quantity of motion possessed by a moving body.
What’s the equation for momentum?
Momentum= mass * velocity =kgm/s
Define acceleration?
The rate of change in velocity.
What’s the equation for acceleration ?
Acceleration= (final velocity-initial velocity) =m/s/s
time taken
Define force?
A push or pull that alters the state of motion of an object.
What’s the equation for force?
Force= mass* acceleration =N
What are internal forces?
The forces created by muscular contractions acting on the skeleton.
What are external forces?
The forces created outside the body.
- Weight
- Reaction force
- Air resistance
- Friction
What affects can force have?
- Create a motion
- Accelerate a force
- Decelerate a force
- Change the direction of a body
- Change the shape of a body
Define stability?
The ability of a body to resist motion and remain at rest
What four things affect stability?
- Mass of the object
- Height of COM
- Base of support
- Line of gravity (if goes through base of support= increased stability)
Define COM?
The point at which the body is balanced in all directions, whilst also being a point of rotation.
Can be MANIPULATED to improve performance.
Vertical forces?
Weight- the gravitational pull that the earth exerts on a body. ALWAYS ACTS THROUGH THE COM (N)
Reaction force- an equal and opposite force in response to gravity. ALWAYS ACTS THROUGH THE LIMB IN CONTACT WITH THE GROUND. (N)
Horizontal forces?
Friction- the force that opposes the motion of two surfaces in contact. ALWAYS ACTS THROUGH LIMB IN CONTACT WITH GROUND (N)
Air resistance- the force that opposes the motion of a body travelling through the air. ALWAYS ACTS THROUGH COM (N)
Factors affecting friction?
- Roughness of the surfaces in contact. eg:spikes
- Roughness of the ground eg: rubber track
- Temperature of surfaces eg: heating F1 tyres
- Mass/size of body eg: carbon fibre
Factors affecting air resistance?
- Velocity, faster = greater ar.
- Shape =streamlining
- Cross-sectional area
- Smoothness of surface eg: licra
Balanced forces?
- 2 or more opposing forces are equal in size.
- No change in motion
- Constant velocity
- Net force= 0
Unbalanced forces?
- 2 or more opposing forces are unequal in size and one EXCEEDS the other
- Change in motion
- Acceleration or deceleration
- Net force= positive or negative
How is the COM used by a Fosby Flop high jumper to maximise performance?
TAKE OFF
Height of COM increased as performer lifts knees
COM remains in the body
FLIGHT/ ROTATION High jumper bends forwards Arches back COM moved from inside body to create an axis of rotation "HIGH JUMPER ROTATES ABOUT THEIR COM" "Greater height achieved"
