1. JointMovementAgonistAntagonist Elbow Shoulder Trunk Knee 1 2

2. Balance and Stability

3. Gravity What is gravity? It is a force that pulls all objects towards the ground. It stops us flying off into space It is applied constantly, it pulls everything towards the centre of the earth at the same speed When a ball is thrown up into the air, gravity is the force acting to pull it back down to the ground

4. Centre of Gravity The centre of gravity is the point located on an object where the mass is evenly distributed For symmetrical objects like a ball the centre of gravity is the actual centre Centre of gravity

5. COG - Humans For irregular objects that can change their shape the centre of gravity is always changing. Eg. Humans For normal human beings standing upright, their centre of gravity lies around the area of their navel. This can change depending on what position the body is in eg when a person is doing a bridge Centre of gravity

6. Line of Gravity Is the vertical line that passes through the centre of gravity to the ground Base of support Line of gravity Centre of gravity

7. Base of support Is the area within an object’s point of contact with the ground. The larger the area the base of support covers, the more stable an object will be. Base of support

8. Balance An object is balanced when forces acting on it are equal – this referred to as stable There are two forms of balance: Static – when a balance is held in a position Dynamic – is balancing when moving Anything can be balanced if its centre of gravity is directly over its base.

9. How do these people remain balanced?

10. Principles of Balance Balance is a desirable attribute in the performance of many skills. A body is most stable when the 3 principles of balance are applied 1Anything can be balanced if its centre of gravity is directly over its base of support 2The wider the base of support the more balanced or stable the object of body is. 3The lower the centre of gravity the more balanced or stable the object is. As one body part moves another must move to compensate that movement

11. 2. Explain how the shooter in the image could make herself more stable while shooting. (Refer to the principles of balance to help you) 1. Explain why it is important to be stable when shooting in netball. Applying knowledge (assessment) 3. Justify your answer in Q2 by stating how and why you think this will help improve performance.