5.1 Biomechanical Movement Flashcards
State newtons 1st law
Law of Inertia
A force is required to change the state of motion of an object
State newtons 2nd law
Law of acceleration
F=m*a
The magnitude and direction of the force determines the magnitude and direction of the acceleration
State newtons 3rd law
For every action (force) there is an equal and opposite reaction (force)
How do you calculate speed
Speed = distance / time
Define centre of mass
The point of concentration of mass, the balance point of the body
Define line of gravity
The line extending vertically downwards from the centre of mass
Define base of support
The region of ground surface which the body contacts with. The larger the area the greater the stability
What four factors affect stability
- The height of the centre of mass- Lowering the centre of mass will increase stability
- Position of the line of gravity- Should be central over the base of support
- Area of the base of support- The more contact points and the larger the base of support the more stable
- Mass of the performer- Greater mass means greater stability
What are the three types of levers
First class levers
Second class levers
Third class levers
What is a first class lever
- A first class lever has the fulcrum in the middle
- Examples of this are Tricep extension And neck flexion and extension
What is a second class lever
- When the resistance is in the centre
- Examples of this are the plantar flexion at the ankle joint
What is a third class lever
- This is when the effort is in the centre
- Some examples include hip knee and elbow flexion
What is a mechanical advantage
When the force arm is longer than the resistance arm
What is a mechanical disadvantage
When the resistance arm is longer than the force arm 
How does a second class lever have a mechanical advantage and disadvantage
Advantage - generate large force
Disadvantage - slow movement, limited ROM
