1. Mechanical Principles
Learning Outcomes
Recap - What is balance, are there different types of balance?
Recap - Centre of gravity
Recap - Body tension
Transfer of Weight and benefits to performance if completed effectively
Force and the application of force.
Rotation

2. Balance
Balance is the ability to retain the centre of gravity over your base of support. There are two types of balances:
Static balances
2) Dynamic balances

3. Centre of Gravity Centre of gravity is to do with stability.
The heavier you are, the more stable you will be
To be balanced your centre of gravity should be inside your base
A low position with a wide base is more balanced

4. Centre of Gravity

5. Body Tension
For technique to be effective it is helpful if the major muscles involved in balances have good body tension.

6. Transfer Of Weight
The transfer of weight allows you to move your body from one place to another. How well you transfer your weight involves considering how well balanced you are when performing.
To transfer your weight in any direction, you must apply a force in the opposite direction. The force is created when you contract your muscles.
At times, this can be single actions such as throwing the javelin. At other times, for example when running, simple actions are repeated.
Name 2 activities, describe one technique which requires a single transference of weight and describe another technique which requires repeated transference of weight

7. Application of Force
When performing different skills and techniques different forces are applied and resisted.
For every action there is an equal and opposite reaction (Newton’s third law)

8. Application of Force
If speed is required then the greater force applied the better. Differences in the mass of the body will affect performance.
If the force applied to the sprinting block (100m sprint) is the same the athlete with a smaller mass will accelerate at a quicker rate.

9. Force
You must apply force in one direction to move in the opposite direction.
Look at the following examples. Explain where force is applied and what direction the person or equipment moves. B A. C

10. Rotation
In different activities you rotate (turn) in order to carry out skills and techniques.
When throwing the discus in athletics you turn around in a spinning back-to-front movement to generate power. This is a complex technique. You build up speed before throwing by quickly turning until you have regained balance.
You can also rotate by performing a forward roll.
Name two skills in which you turn head over heals.

11. Mechanical Principles
A. What is the importance of transfer of weight when completing an ‘overhead clear’?
B. When completing a ‘headstand’ what affect would having a small base have your performance?
C. Why is body tension important when completing static balances?
D. Where must your centre of gravity be maintained to hold a balance?
E. Give an example of a dynamic balance?