Biomechanics 1 Flashcards
Define ‘Biomechanics’
Study of motion & effects of forces relative to the body, applies the law of mechanics & physics to human performance.
List some benefits of Biomechanics
Improve Performance
Prevent Sports Injuries
Improved Sports Equipment
Improve Technology Development
Define ‘Motion’
Occurs when an object has changed position in space & in time, due to the application of forces.
List 2 types of forces & the difference in each
1.Internal Force = Structure of the body that interact to produce movement.
2. External Force = Result in interaction with the body & environment.
Give an example of both types of forces
Internal Force = muscles & tendons in arm/leg.
External Force = Gravity, Friction, Air Resistance, Water Resistance
Define ‘Linear Motion/Translation’
Movement along a straight-line, no rotation & body parts move in the same direction as same speed.
E.g. A cyclist whilst stopped pedaling.
Define ‘Rectilinear Motion’
Movement is linear and occurs through a straight line, this is often represented by the body as a whole or certain point of the body (the head when running).
E.g. A baseball pitch (ball is flat & in a straight line)
Define ‘Curvilinear motion’
Movement is linear but object moves through a curved trajectory, Think about the pathway of a ball during a shot on goal in netball or the flight path of long-distance ski jumper.
E.g. a ball during a shot on goal in netball
Define ‘Angular Motion’
Where all the parts of a body move through a rotational pathway, through the same angle, in the same direction and at the same time
E.g. When a gymnasts performs a giant circle on a bar
Define ‘General motion’
Combination of linear and angular motion
E.g. cyclist may move in a straight line as a result of the rotation of the legs about the hip joint
Explain the difference between Displacement & Distance
Distance Refers to how far you have travelled from your start to finish position
Displacement Measures the overall change in position of a person and is measured in magnitude and direction
What is the formula for Speed
Distance/Time
What is the formula for Velocity
Displacement/Time
What is the formula for Acceleration
Final velocity-initial velocity/Time
What is the formula for Average Speed
Total distance/Total time
What is the formula for Instantaneous speed
Distance/Time
Define ‘Acceleration’
Rate at which velocity of a body changes with respect to time
Positive Acceleration is acceleration increasing/decreasing
Increasing
Negative Acceleration (Retardation) is acceleration increasing/decreasing
Decreasing
Zero Acceleration is acceleration increasing/decreasing
No change in velocity
Define ‘Uniform Acceleration’
When a body accelerates at a constant rate in both magnitude & direction, i.e. The acceleration is the same over time.
Gravity causes an object to accelerate at a constant rate of what
9.8m/s/s
Define ‘Angular Displacement’
Represents the difference in the angle between the start & end position of the body.
Define ‘Angular Distance’
Represents the sum of all angles as a body moves from its start position to its end position.
Define ‘Force’ & give the formula
Push, pull any interaction, that when unopposed will change the motion of an object, it is used to.
= mass x acceleration
5 Examples of how forces work
- Get objects moving.
- Stop objects moving.
- Change the direction of a moving object.
- Change the speed of a moving object.
- Balance another force to keep an object still.
What is the difference between Contact & Non-Contact Force
Contact Force is when forces that act on objects that come into direct contact with another.
Non-Contact is when those forces that act on objects without coming into direct.
Define Newtons 1st Law
A body continuous in its state of rest or state of motion unless acted upon by a force” (Law of Inertia).
Define ‘Inertia’
Describes the amount of resistance to a change in an objects state of motion.
Define Newtons 2nd Law
“The acceleration of a body is proportional to the force applied to it & inversely proportional to the mass of the object.”
Define ‘Newtons 3rd Law’
‘For every action there is an equal & opposite reaction’
Who is responsible for the Action in the Newtons 3rd Law
Athlete
Who is responsible for the Reaction in the Newtons 3rd Law
The opposing force/ force being exerted upon
What does GRF stand for
Ground Reaction Force
What does GRF mean
Force exerted by the ground on a body in contact with it
What is the size of the force when walking
1.2*
What is the size of the force when sprinting
3*
What is the size of the force when jumping
8*
For movement to occur there needs to be what
An imbalance in forces
Give an example of Linear Motion
- An ice skater gliding after they completed a movement
- a cyclist who stops pedaling (straight line motion)
Give an example of Rectilinear Motion
A basketball chest pass or baseball pitch are good examples where the ball’s path is flat and in a straight line
Give an example of Curvilinear Motion
Think about the pathway of a ball during a shot on goal in netball or the flight path of long distance ski jumper
Given an example of Angular Motion
When a gymnasts performs a giant circle on a bar, the entire body rotates, with the axis of rotation passing through the centre of the bar.
