MECHANICAL PRINCIPLES



MECHANICAL PRINCIPLES

Concepts

Balance

Transfer of Weight

Application of Force

Rotation

Resistance

Follow Through

MECHANICAL PRINCIPLES

BALANCE

What is meant by Balance

Balance is achieved by keeping your body weight above your base of support. This can occur when the body is static or moving.

The Basic Principles of Balance

• The larger the base the easier it is to balance, the smaller the base the more difficult it is to balance. For example, a shoulder stand is easier to perform than a handstand.

• The lower the centre of gravity the easier it is to balance, the higher it is the more difficult it is to balance. For example a crouched headstand is easier to perform than an extended headstand.

• The body weight/mass should be kept above the base of support to make the balance stable. For example the hips should be kept above the triangular base of support/shoulders when performing a headstand.

• Movement into a balance should be controlled so that you can stop in/hold the balance position. For example when performing a headstand you should control your movement into the headstand position so that you can stop your hips moving and keep them above your triangular base of support/shoulders.

Effect of balance on performance

|Activity |Skill or situation |How balance is achieved or maintained |Effect on performance |

|Gymnastics |Handstand |I controlled my movement into the |I could hold the handstand steady for 5 |

|(individual) | |handstand and put my hands shoulder |seconds |

| | |width apart tightened my muscles and | |

| | |kept my hips above my shoulders | |

|Football |Dribbling |I slightly bent my legs, which were |I was able to move and change direction |

|(team) | |about shoulder width apart to lower my |quickly while still keeping control of the |

| | |centre of gravity, I kept my body |ball so that I could dribble past my |

| | |weight above my base and tightened my |opponent |

| | |muscles to apply force when I changed | |

| | |direction quickly | |

What is meant by Centre of Gravity

The centre of gravity is the point at which all weight tends to be concentrated so that the body is balanced in all directions. This can occur when the body is static or moving.

Examples of the effect of Centre of Gravity on Performance

|Activity |Skill or situation |Centre of gravity during performance to be |Effect on performance |

| | |balanced | |

|Gymnastics |Handstand |Hips kept above shoulders |I can hold the handstand still for 5 |

|(individual) | | |seconds |

|Football |Dribbling |Hips above feet when dribbling |I can quickly transfer my weight in |

|(team) | | |different directions because I am |

| | | |balanced |

What is meant by the size of base

The size of your base is the area covered by the points of contact that your body makes with the floor/ground.

The effect of the size of your base on performance

|Activity |Skill or situation |Size of base during performance to be |Effect on performance |

| | |balanced | |

|Gymnastics |Headstand |Triangular base made with hands and |I can hold the balance still for 5 |

|(individual) | |forehead |seconds because I have a large base |

|Gymnastics |Handstand |My hands are placed close together on the|I am unable to hold the handstand steady|

|(individual) | |floor |for any length of time due to my small |

| | | |base |

|Football |Faking |Feet are roughly shoulder width apart |Because I am balanced due to the large |

|(team) | |when attempting to fake my opponent |base I can quickly transfer my weight to|

| | | |move one way and then another to lose my|

| | | |opponent |

|Basketball |Dribbling |I had my feet too close together when |I was unable to transfer my weight |

|(team) | |dribbling |quickly from one direction to another |

| | | |and I could not lose my opponent |

What is meant by having body weight above the base off support

During static balances the body weight must be held still above the base of support. If the body weight moves out-with the base of support the balance cannot be held. To be balanced during movement, if the body weight moves out-with the base of support then body control will be lost.

The effect of having body weight above the base of support on performance

| Activity |Skill or situation |how body weight is kept above base of |Effect on performance |

| | |support to be balanced | |

|Gymnastics |Handstand |Hips kept above shoulders |I can hold the handstand still for 5 |

|(individual) | | |seconds |

|Football |Dribbling |Hips above feet when dribbling |I can quickly transfer my weight in |

|(team) | | |different directions because I am |

| | | |balanced |

What is meant by body tension

Body tension occurs when muscles/muscle groups contract to hold the body in stillness or to apply a force.

The effect of body tension on performance

|Activity |Skill or situation |How body tension is used |Effect on performance |

|Gymnastics |Handstand |I contracted/tightened the muscles I was |I was able to hold my balance still |

|(individual) | |using as I balanced to hold the body still |for 5 seconds |

|Badminton |Smash |As I struck the shuttle with the racket, I |I was able to apply a large force to |

|(individual) | |contracted/tightened the muscles used to |the shuttle so that it was hit hard |

| | |smash |on fast and my opponent found it |

| | | |difficult to return |

|Rugby (team) |Scrum |As we pushed in the scrum we |We were able to apply a large force |

| | |contracted/tightened the muscles/muscle |so that our opponents could not push |

| | |groups used in the push to hold our scrum |our scrum backwards |

| | |steady | |

|Football |Penalty kick |As I struck the ball, I tensed the |I was able to apply a large force to |

|(team) | |muscles/muscle groups used when kicking so |the ball so that I kicked it hard and|

| | |that I could apply a large force to the ball|fast and the goalkeeper could not |

| | | |save it. |

Changing body position to increase stability

By changing your body position you can increase stability or make it easier to hold a balance.

|Activity |Skill or situation |Change made to body position |How change of body position improved |

| | | |performance |

|Gymnastics |Headstand |I changed from an extended headstand |I was not able to perform the headstand |

|(individual) | |position to a crouched headstand position|in the extended position but when I |

| | | |lowered my centre of gravity I could hold|

| | | |the headstand position steady more easily|

|Basketball |Control dribble |I bent my legs more to lower my body when|I could bounce the ball lower and I could|

|(team) | |pressured by an opponent |more easily change my direction by |

| | | |transferring my weight quickly so that I |

| | | |was able to keep control of it in a tight|

| | | |pressured situation |

TRANSFER OF WEIGHT

Definition of transfer of weight

Transfer of weight is achieved by moving the body weight from one part of the body to another.

Efficient transfer of weight can result in increased power in striking throwing and pushing actions.

|Activity |Skill/Tech |Role or position |Main part of |Weight transfer |Effect on Performance |

| | | |body used |From - To | |

|Basketball |Jump shot |Guard |Whole body |Down to up |I can jump up high to elevate myself above the |

|(team) | | | | |defender and get power and height on the ball so |

| | | | | |that it reaches/drops down on the basket. |

|Hockey |Drive |Midfielder |Legs and |Back foot to |I can get a faster swing of the stick through the|

|(team) | | |arms |front foot |ball so that it goes hard and fast and is not |

| | | | | |intercepted |

|Basketball |Javelin pass |Centre |Arm |Back foot to |I can build up speed on the ball before release |

|(team)l | | | |front foot |so that it goes far and fast to my team mate and |

| | | | | |is not intercepted |

|Athletics |High Jump |N/A |Whole body |Down to up |I can drive up powerfully to jump high to clear |

|(individual) | | | | |the bar |

|Badminton |Smash |N/A |Arm |Back foot to |I can build up speed in the racket head as I move|

|(individual) | | | |front foot |forward quickly so that the shuttle is hit hard |

| | | | | |downwards to win the point |

|Basketball |Chest Pass |Centre |Legs |Back foot to |I can apply force to the ball so that it goes |

|(team) | | |And |front foot |flat and hard to its target and is not |

| | | |arms | |intercepted |

|Football |Throwing a fake |Centre forward |Legs |Side to side |I can make my opponent think that I am going one |

|(team) | | | | |way and by changing direction quickly to go in |

| | | | | |the opposite direction I can lose my marker |

Effect of Weight Transfer on Performance

Individual Activity - Badminton

Skill/Technique - Overhead Clear

Part of the Body - Arm/upper body

Type of Action - Striking action

Description of how and when Weight is Transferred

I moved my weight onto my back foot as I adopted the ready position under the shuttle. As I swung

forward to strike the shuttle, I transferred my weight onto my front foot.

Effect of Weight Transfer on Performance

I was able to apply a powerful force back and down as I transferred my weight forward. This enabled

me to turn quickly to get a fast racket head through the shuttle so that it went high and long to force

my opponent to the rear of their court.

Team Activity - Football

Skill/Technique - Faking an opponent

Part of the Body - Leg/lower body

Type of Action - Pushing action

Description of how and when Weight is Transferred

I moved my weight onto my right foot, and when my opponent moved to their left, I very quickly,

by driving down onto my right foot, transferred my weight sideways onto my left foot to change

direction quickly to go around my opponent.

Effect of Weight Transfer on Performance

I can make my opponent/the defender think that I am going to the right and then by changing

direction very quickly to move to the left, I can lose my marker to get into space to cross the

ball/shoot at goal

Team Activity - Basketball

Skill/Technique - Javelin pass

Part of the Body - Arm/upper body

Type of Action - Throwing action

Description of how an when Weight is Transferred

I moved my weight backwards onto my back/right foot and then very quickly by driving back and

down onto my right foot, I transferred my weight forwards onto my left/front foot just as I started

to bring the ball forwards.

Effect of Weight Transfer on Performance

I was able to bring the ball forward quickly, building up speed on it before release, so that I got

power into the pass and it flew far and fast to my team mate without being intercepted.

APPLICATION OF FORCE

Definition of Application of Force

By contracting the muscles force can be applied against a resistance to achieve thrust/propulsion

in the opposite direction.

The more powerful the muscle contraction, the greater the force applied and the greater the

thrust/propulsion achieved.

|Activity |Skill/Tech |Direction |Direction |Main part |Effect on Performance |

| |or |of |of Thrust |of | |

| |Situation |Force |or |body used | |

| | | |Propulsion | | |

|Athletics |Sprint | Back |Forward |Legs |By powerfully straightening the legs |

|(ind) |start |+ down |+ up | |against the blocks I can get a |

| | | | | |powerful thrust up and forward to get |

| | | | | |into my stride quickly before my |

| | | | | |opponents |

|Rugby |Scrum | Back |Forward |Legs |By powerfully pushing with our legs |

|(team) | | | | |We can apply a great force back so |

| | | | | |that our scrum moves forward |

| | | | | |pushing our opponents back |

|Swim |Push start | Back |Forward |Legs |By powerfully straightening my legs |

|(ind) |off the | | | |back against the wall I can get a |

| |wall | | | |large thrust forward so that I can get |

| | | | | |into my stroke quickly/before my |

| | | | | |opponents |

|Football |Faking | To the |To the left |Legs |By pretending to go to my right and |

|(team) | |right | | |then applying a large force by driving |

| | | | | |off my right foot to go quickly to my |

| | | | | |left I can lose my marker |

|Swim |Front | Back |Forward |Arms and |By pushing back against the |

|(ind) |Crawl | | |legs |resistance of the water powerfully I |

| | | | | |get a great propulsion forward so |

| | | | | |that I can swim fast and win the race |

|B/ball |Rebound | Down |Up |Legs |By powerfully straightening the legs |

|(team) | | | | |I can apply a large force against the |

| | | | | |resistance of the floor so that I can |

| | | | | |get a powerful thrust upwards to |

| | | | | |jump high and win the rebound |

Effect on Performance of Application of Force

Team Activity - Football

Skill/Technique/Situation - Faking to lose opponent

Direction of force applied - Sideways/to the right

Direction of thrust achieved - Sideways to the left

Description of how Force is applied

By applying a powerful force to the right by straightening my leg against the resistance of the

ground, I changed my direction of movement quickly, to go sideways to the left.

Effect on performance

By changing my direction quickly, I was able to deceive my opponent and get away from him/her

into space.

Team Activity - Basketball

Skill/Situation - Rebounding

Direction of force applied - Down

Direction of thrust achieved - Up

Description of how Force is applied

By powerfully straightening my legs, I can apply a large force down against the resistance of the

floor which gives me a powerful thrust upwards.

Effect on performance

I can jump up higher than my opponents and win the rebound.

Individual Activity - Athletics

Skill/Situation - Sprint start

Direction of force applied - Back and down

Direction of thrust achieved - Forward and up

Description of how Force is applied

By powerfully straightening my legs, I could apply a large force back and down against the resistance

of the blocks. This gave me powerful thrust forward and up.

Effect on performance

I was able to get away quickly at the start of the race to get in front of my opponents.

Individual Activity - Swimming

Skill/Situation - Front Crawl

Direction of force applied - Back

Direction of thrust achieved - Forward

Description of how Force is applied

By powerfully pushing back with the arms and legs, I can apply a large force against the resistance

of the water which gives me a large forward propulsion.

Effect on performance

I can swim quickly through the water, faster than my opponents so that I win the race.

ROTATION

Definition of rotation

Rotation is the movement of the body or part of the body around a central axis.

Effect of changes of Body Shape on Rotation

Activity - Trampolining

Skill/Technique - Front Somersault

Change made to Body Shape

I tucked by body into a tight ball shape as I turned.

Effect on Rotation

The tighter the tuck the faster the rotation.

Effect on Performance

I was able to rotate my body fully to land on my feet

Activity - High Board Diving

Skill/Technique - Open Back somersault

Change made to Body Shape

I opened my body up fully as I rotated in the somersault.

Effect on Rotation

The more open my body, the slower my rotation.

Effect on Performance

I was able to slow down my rotation so that I didn't over-rotate and I could enter the water hands

first, with my body straight.

RESISTANCE

Definition of resistance

Resistance occurs as a result of friction occurring between an object and an external force or other

object.

Resistance as an Advantage

|Activity | Skill/tech |Resistance | How resistance | Effect on Performance |

| |or |given by |is used | |

| |situation | | | |

|Swim |Front crawl |Water |Force is applied by |The greater the force applied |

| | | |the muscles of the |backwards the greater the |

| | | |arms and legs to |propulsion I get forward and the |

| | | |push back against |faster I can swim so that I win |

| | | |the resistance of the |the race |

| | | |water to get | |

| | | |propulsion forwards | |

|Athletics |100 metres |Wind |A strong wind |This means that I can run faster |

| | | |Blowing at my back |and I can win the race |

| | | |forces me forward so | |

| | | |that I can run faster | |

|B/ball |Rebound |Floor |I bend and then |This enables me to jump up high |

| | | |powerfully straighten |so that I can win the rebound |

| | | |my legs to apply | |

| | | |force down against | |

| | | |the resistance of the | |

| | | |floor to get thrust | |

| | | |upwards | |

|Football |Fake |Ground |By powerfully driving |I can make my opponent think |

| | | |down off my right |that I am going to my right and |

| | | |foot against the |then quickly go to my left to lose |

| | | |resistance of the |him/her/to move into space |

| | | |floor I can quickly | |

| | | |change my direction | |

| | | |to go to my left | |

Team Activity - Basketball

Skill/Technique - Rebounding

Resistance given by - Floor

How Resistance is used to Advantage

I bend and then powerfully straighten my legs to apply force downwards against the resistance of

the floor to get thrust upwards

Effect on Performance

By powerfully straightening my legs to apply force downwards, I can jump up higher than my

opponents to win the rebound.

Individual Activity - Swimming

Skill/Technique - Front Crawl

Resistance given by - Water

How Resistance is used

Force is applied by the muscles of the arms and legs to push back against the resistance of the

water to get propulsion forward.

Effect on Performance

The harder/greater the push back against the resistance of the water the more propulsion I achieve

and the faster I can swim, so that I can swim faster than my opponents and win the race.

Resistance as a Disadvantage in Individual activities

|Activity |Skill/tech |Resistance |How Resistance | How body | Effect on Performance |

| |or |given by |hinders |shape changed | |

| |Situation | | | | |

|Swim |Front |Water |To move |Streamline |By streamlining my body I |

|(ind) |Crawl | |forward |my body by |offer less surface area to the |

| | | |I have to cut |putting my |resistance of the water and I |

| | | |through the |head between |can cut through the water |

| | | |water which |my arms and |more easily to swim faster to |

| | | |pushes |by straightening |win the race |

| | | |against me |my legs and | |

| | | |and slows me |keeping them | |

| | | |down |together | |

|Athletics | 100 |Air/wind |As I run the |I leaned |I offer less of a surface area |

|(ind) |metres | |air/wind |further |to the resistance of the wind |

| | | |pushes |forward |which lets me run faster so |

| | | |against me |putting my |that I won the race |

| | | |slowing me |head down | |

| | | |down | | |

|Cycling |Cycling |Wind |As I cycle the |I leaned |I offer less of a surface area |

|(ind) |against | |air/wind |further |to the resistance of the wind |

| |the wind | |pushes |forward |which lets me cycle faster so |

| | | |against me |putting my |that I won the race |

| | | |slowing me |head down | |

| | | |down |further over | |

| | | | |the | |

| | | | |handlebars | |

Resistance as a Disadvantage in Team activities

|Activity |Skill/tech |Resistance |How Resistance |Effect on | Tactic to overcome |

| |or |given by |hinders |Performance | |

| |Situation | | | | |

|Football |Long pass |Wind |The wind |The ball falls |Hard pass played along |

|(team) |up field | |Holds the ball |short and is |the ground into feet or |

| | | |up and it falls |intercepted |into space |

| | | |short of the | | |

| | | |target | | |

|Rugby |Kick at |Wind |Wind from the |The ball |Aim further to the right |

|(team) |goal | |right pushes |moves to the |when kicking to allow for |

| | | |the ball to left |left and |movement in the air so |

| | | |in flight |misses |that the ball goes |

| | | | |the goals |between the posts |

Team Activity - Rugby

Skill/Technique - Kicking for goal

Resistance given by - Wind

How Resistance is hinders performance

Wind from the right pushes the ball to the left in flight so that the ball moves in the air and misses

the target.

Tactic to overcome resistance

Aim further to the left when kicking to allow for movement in the air so that the ball goes between

the posts.

Individual Activity - Cycling

Skill/Technique - Cycling against the wind

Resistance given by - Wind

How Resistance is hinders performance

The wind blowing into my face makes a greater resistance for me to cycle against which slows

me down.

Tactic to overcome resistance

I lean forward over the handlebars of the bike to reduce the amount of my body presented to the

wind so that I can cycle faster.

FRICTION

Definition of Friction

Friction is caused when two objects rub together which leads to an increase in resistance.

Effect of increased Friction on Performance

Activity - Athletics

Skill/Technique - 100 metre sprint

How Friction is increased

Spikes are worn to increase the friction with the track which increases the resistance that can be

achieved.

Effect of increased Friction on Application of Force

Wearing spikes gives me a better grip of the track, which enables me to apply a greater force

downwards and backwards against the resistance of the track so that I get more thrust upwards

and forwards.

Effect of increasing Friction on Performance

Due to the better grip on the track and the increased forward thrust I can run faster than my

opponents and I win the race.

Effect of reduced Friction on performance

Activity - Skiing

Skill/Technique - Skiing downhill

How friction is reduced

I put wax on the bottom of my skis which makes the skis slide easily across the snow, reducing

the resistance.

Effect of reducing Friction on Performance

Because my skis were sliding across the snow more easily I was able to ski faster than my

opponents and win with the quickest time.

STREAMLINING

Definition of Streamlining

Streamlining occurs when you put your body into a shape and position to present as small as

possible a surface area to a resistance. This can reduce the resistance you need to overcome

and improve your performance.

Effect of adopting a streamlined position on performance

Activity - Swimming

Skill/Technique - Front Crawl

Resistance to be overcome - Water

How the body shape is changed to make it Streamlined

I made my body straighter on the surface of the water by putting my head between my arms and

by putting my legs together.

Effect of adopting streamlined position on reducing Resistance

Due to my straighter body shape I offered a reduced surface area to the water, so that I can cut

through the water more easily.

Effect on performance of adopting a more Streamlined position

As I can cut through the water more easily I can swim faster than my opponents and win the race.

Activity - Cycling

Skill/Technique/Situation - Cycling against the wind resistance to be overcome - wind/air

How the body shape is changed to make it Streamlined

I bent my body more over the handlebars.

Effect of adopting streamlined position on reducing Resistance

Due to my hunched body shape I offer a reduced surface area to the wind/air, so that I can cut

through the wind/air more easily.

Effect on performance of adopting a more Streamlined position

As I can cut through the wind/air more easily I can cycle faster than my opponents and win the race.

FOLLOW THROUGH

Definition of follow through

In striking/kicking/throwing actions the part of the body (arm, leg, hand etc) or piece of

equipment (racket, club stick etc) continues after the object that has been struck or released

in the direction of the target.

Importance of Follow Through to striking/kicking/throwing actions

• Increases power

• Increases accuracy

• Maintains balance

• Prevents injury

Effect of follow through on performance

Team Activity - Football

Striking Action - Shooting at goal

Description of follow through

After contacting/kicking the ball the foot continues to follow the ball towards the goal.

Effect of Follow Through on Performance

As my foot continues after the ball it gives the kick more power and I hit it accurately towards

the goals so that I score a goal

Team Activity - Basketball

Throwing Action - Javelin pass

Description of follow through

After releasing the ball the hand continues to follow the ball towards the player I am passing to.

Effect of Follow Through on Performance

Following through gives my pass more power and accuracy so that it flies far and straight and

is not intercepted

Individual Activity - Badminton

Striking Action - Smash

Description of follow through

After contacting/hitting the shuttle the racket head continues to follow it forwards and downwards

towards the ground.

Effect of Follow Through on Performance

Following through gives my smash more power and accuracy so that my opponent cannot return it

and I win the point.

Individual Activity - Athletics

Throwing Action - Javelin

Description of follow through

After releasing the javelin the arm continues to follow it forwards and upwards into the air/at an

angle of 45 degrees.

Effect of Follow Through on Performance

Following through after releasing the javelin gives my throw accuracy and more power so that it

flies furthest and I win the event.

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download