MECHANICAL PRINCIPLES - WordPress.com … · Web viewMECHANICAL PRINCIPLES. BALANCE. What is...

MECHANICAL PRINCIPLES

Concepts

BalanceTransfer of WeightApplication of ForceRotationResistanceFollow 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(individual)

Handstand I controlled my movement into the handstand and put my hands shoulder width apart tightened my muscles and kept my hips above my shoulders

I could hold the handstand steady for 5 seconds

Football (team)

Dribbling I slightly bent my legs, which were about shoulder width apart to lower my centre of gravity, I kept my body weight above my base and tightened my muscles to apply force when I changed direction quickly

I was able to move and change direction quickly while still keeping control of the ball so that I could dribble past my opponent

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


Centre of gravity during performance to be balanced



Handstand Hips kept above shoulders

I can hold the handstand still for 5 seconds

Football (team)

Dribbling Hips above feet when dribbling

I can quickly transfer my weight in 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


Size of base during performance to be balanced



Headstand Triangular base made with hands and forehead

I can hold the balance still for 5 seconds because I have a large base


Handstand My hands are placed close together on the floor

I am unable to hold the handstand steady for any length of time due to my small base

Football (team)

Faking Feet are roughly shoulder width apart when attempting to fake my opponent

Because I am balanced due to the large base I can quickly transfer my weight to move one way and then another to lose my opponent

Basketball (team)

Dribbling I had my feet too close together when dribbling

I was unable to transfer my weight 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


how body weight is kept above base of support to be balanced



Handstand Hips kept above shoulders

I can hold the handstand still for 5 seconds

Football (team)

Dribbling Hips above feet when dribbling

I can quickly transfer my weight in 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


How body tension is used Effect on performance


Handstand I contracted/tightened the muscles I was using as I balanced to hold the body still

I was able to hold my balance still for 5 seconds

Badminton (individual)

Smash As I struck the shuttle with the racket, I contracted/tightened the muscles used to smash

I was able to apply a large force to the shuttle so that it was hit hard on fast and my opponent found it difficult to return

Rugby (team)

Scrum As we pushed in the scrum we contracted/tightened the muscles/muscle groups used in the push to hold our scrum steady

We were able to apply a large force so that our opponents could not push our scrum backwards

Football (team)

Penalty kick

As I struck the ball, I tensed the muscles/muscle groups used when kicking so that I could apply a large force to the ball

I was able to apply a large force to the ball so that I kicked it hard and 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.


Change made to body position

How change of body position improved performance


Headstand I changed from an extended headstand position to a crouched headstand position

I was not able to perform the headstand in the extended position but when I lowered my centre of gravity I could hold the headstand position steady more easily

Basketball (team)

Control dribble

I bent my legs more to lower my body when pressured by an opponent

I could bounce the ball lower and I could 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 body used

Weight transferFrom -

To

Effect on Performance

Basketball (team)

Jump shot

Guard Whole body

Down to up

I can jump up high to elevate myself above the defender

and get power and height on the ball so that it

reaches/drops down on the basket.

Hockey(team)

Drive Midfielder Legs and

arms

Back foot to

front foot

I can get a faster swing of the stick through the ball so that it goes hard and fast and is

not interceptedBasketball

(team)lJavelin pass

Centre Arm Back foot to

front foot

I can build up speed on the ball before release so that it goes far and fast to my team mate and is not intercepted

Athletics(individual)

High Jump

N/A Whole body

Down to up

I can drive up powerfully to jump high to clear the bar

Badminton(individual)

Smash N/A Arm Back foot to

front foot

I can build up speed in the racket head as I move

forward quickly so that the shuttle is hit hard downwards

to win the pointBasketball

(team)Chest Pass

Centre LegsAndarms

Back foot to

front foot

I can apply force to the ball so that it goes flat and hard

to its target and is not intercepted

Football(team)

Throwing a fake

Centre forward

Legs Side to side

I can make my opponent think that I am going one 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.


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


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.


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/propulsionin the opposite direction.

The more powerful the muscle contraction, the greater the force applied and the greater the thrust/propulsion achieved.

Activity Skill/Tech or Situation

Direction of Force

Direction of Thrust orPropulsion

Main part ofbody used


Athletics(ind)

Sprint start

Back+ down

Forward + up

Legs By powerfully straightening the legsagainst the blocks I can get a powerful thrust up and forward to getinto my stride quickly before myopponents

Rugby(team)

Scrum Back Forward Legs By powerfully pushing with our legs We can apply a great force back so that our scrum moves forward pushing our opponents back

Swim(ind)

Push start off the wall

Back Forward Legs By powerfully straightening my legsback against the wall I can get a large thrust forward so that I can getinto my stroke quickly/before my opponents

Football(team)

Faking To the right

To the left Legs By pretending to go to my right andthen applying a large force by drivingoff my right foot to go quickly to my left I can lose my marker

Swim(ind)

Front Crawl

Back Forward Arms and legs

By pushing back against the resistance of the water powerfully I get a great propulsion forward so that I can swim fast and win the race

B/ball(team)

Rebound Down Up Legs By powerfully straightening the legsI can apply a large force against theresistance of the floor so that I can get a powerful thrust upwards tojump high and win the rebound

Effect on Performance of Application of Force


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.


Skill/Situation - Rebounding

Direction of force applied - Down

Direction of thrust achieved - Up


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


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.


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


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.


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.


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.


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

Resistancegiven by

How resistance is used


Swim Front crawl Water Force is applied by the muscles of the arms and legs to push back againstthe resistance of thewater to get propulsion forwards

The greater the force applied backwards the greater thepropulsion I get forward and thefaster I can swim so that I win the race

Athletics 100 metres Wind A strong windBlowing at my back forces me forward sothat I can run faster

This means that I can run faster and I can win the race

B/ball Rebound Floor I bend and then powerfully straightenmy legs to apply force down againstthe resistance of thefloor to get thrust upwards

This enables me to jump up highso that I can win the rebound

Football Fake Ground By powerfully driving down off my right foot against the resistance of the floor I can quickly change my direction to go to my left

I can make my opponent think that I am going to my right andthen quickly go to my left to losehim/her/to move into space


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


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 thewater to get propulsion forward.


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 or Situation

Resistance given by

How Resistance hinders

How body shape changed


Swim(ind)

Front Crawl

Water To move forwardI have to cut through the water which pushes against me and slows me down

Streamlinemy body by putting my head between my arms and by straighteningmy legs and keeping them together

By streamlining my body I offer less surface area to theresistance of the water and Ican cut through the watermore easily to swim faster towin the race

Athletics(ind)

100 metres

Air/wind As I run the air/wind pushesagainst me slowing me down

I leanedfurther forwardputting my head down

I offer less of a surface area to the resistance of the wind which lets me run faster sothat I won the race

Cycling(ind)

Cycling against the wind

Wind As I cycle the air/wind pushes against me slowing me down

I leanedfurther forwardputting my head down further overthe handlebars

I offer less of a surface area to the resistance of the wind which lets me cycle faster sothat I won the race

Resistance as a Disadvantage in Team activities

Activity Skill/tech orSituation

Resistance given by

How Resistance hinders


Tactic to overcome

Football(team)

Long pass up field

Wind The wind Holds the ballup and it falls short of the target

The ball falls short and is intercepted

Hard pass played along the ground into feet or into space

Rugby(team)

Kick at goal

Wind Wind from the right pushes the ball to leftin flight

The ball moves to theleft and missesthe goals

Aim further to the rightwhen kicking to allow for movement in the air sothat the ball goes 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 beachieved.

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.

STREAMLININGDefinition of StreamliningStreamlining 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


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 towardsthe goals so that I score a goal


Throwing Action - Javelin pass


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


Following through gives my pass more power and accuracy so that it flies far and straight andis not intercepted

Individual Activity - Badminton

Striking Action - Smash


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


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


After releasing the javelin the arm continues to follow it forwards and upwards into the air/at an angle of 45 degrees.


Following through after releasing the javelin gives my throw accuracy and more power so that it flies furthest and I win the event.

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