Balance

Definition of terms Balance- is the ability to retain your centre of gravity over your base of support. Two types: Static- e.g. Gymnastics- headstand Dynamic- e.g. Skiing- when changing direction

Centre of Gravity- is an invisible line that runs through the point at which your body is ‘most’ balanced. Body tension- is the ability of a muscle or a group of muscles to contract in order to hold/control the body in position.

Centre of Gravity

Effects on Performance Improving skills/performance: Having a ‘good’ level of balance is important in all sports. If you cannot hold your balance whilst performing a skill, your technique will suffer. E.g. A volley in Football, a Drive in Golf.

Effects on Performance Large/small base Generally the larger surface area your base of support covers the ‘more ‘ balanced you will be. Body weight over base Your centre of gravity must be over your base of support to maintain your balance.

Questions Q1. State the definition for Balance? __________________________________________ Q2(a). What is the difference between a static and a dynamic balance? __________________________________________________ Q2(b). Give an example of each, commenting how you controlled your movements to stay balanced? ________________________________________________________

Transfer of Weight

Definition Transfer of weight- is the ability of a force to be transferred through part or the whole body. E.g. Tennis serve- legs to racquet Golf Drive- back-foot to front foot

Application Of Force

Definition 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)

A footballer kicking the ball A shot putter ‘putting’ the shot In both these examples, speed and power are important in applying force. The direction of the force is also important. In the football example the footballer is trying to keep the shot low and close to the ground. For the shot putter there is an optimum angle at which to putt the shot.

Resisting Forces Starting Blocks Studded Boots Chalk Dust To help performers resist the forces involved in completing different actions various types of equipment are used. Sprinters use starting blocks, outdoor games players use studded boots to provide grip and resistance. By contrast, shot putters use chalk dust to reduce friction to make the shot putt easier to throw.

Application of Force Activity Skill/Technique Type of Action Application of Force Benefit Swimming BackstrokeStarting As I push backwards against the wall, I am powerfully extending and straightening my legs. This enables me to get into my swimming stroke quickly after my push off and glide are complete. BasketballReboundingJumping As I push down against the floor, I am powerfully extending and straightening my legs. This enables me to jump high and secure possession of the ball.

Rotation

Definition Rotation is the movement of the body (or part of the body) around a central axis. In different activities you rotate (turn) in order to carry out effective skills and techniques.

Rotation In different activities you rotate (turn) in order to carry out effective skills and techniques, eg discus hammer throw gymnastics

Rotation 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 your feet around. After the throw you follow through and keep turning until you have regained your balance.

Rotation As well as rotating around you also can rotate by turning head over heels. Front Somersault The tighter the tuck the quicker you will rotate. Rotation is important when completing a front somersault in trampolining.

Rotation Another form of rotation is when you turn sideways. cartwheel A cartwheel – where you turn over from feet to hand, balancing on the ground before returning to feet on the ground – is an example of this type of rotation.

Mechanical Principles Resistance

When you apply a force there will be a resistance Resistance can either be an advantage of disadvantage.

Advantage When sprinting in athletics the starting blocks are an advantage. They provide a resistance, by powerfully straightening the legs against the starting blocks the sprinter can quickly gain speed.

Disadvantage The swimmer is having difficult in swimming effectively due to the resistance created by poor streamlining.

The second swimmer the leg action is more effective, less water is displaced, the swimmer’s centre of gravity is higher. Overall, the forces applied are overcoming the resistance created by the water in a more effective way.

Mechanical Principles Follow Through

A good follow through is part of effective performance and follows on from the preparation and action phases in different skills and techniques.

Kicking and Throwing In rugby the follow through is in the direction of the shot. In baseball the throwing action the arms follows the intended direction of the throw.

In other actions the follow through involves body rotation. The ball and socket joints in the hips and shoulder help rotation in the two different striking actions in tennis and golf.

Effect of Follow Through on Performance When completing different skills and techniques it is important for effective performance that kicking, striking/hitting and throwing actions have a good follow through. An effective follow through follows the preparation and action phases in different skills and techniques.