Biomech Presentation

Biomechanics for Cricket

Coaching ApplicationsCoaching Applications

PART “A”

THE BASICSTHE BASICS

“It is ESSENTIAL coaches and players

understand these principles”

“Many people believe coaching is about ANALYSIS”…

…“often too much analysis causes PARALYSIS”

Communication is the key – K.I.S.S. principle

PARALYSIS BY ANALYSIS

BIOMECHANICS SUPPLIES THE SIMPLICITIES AND THE WHY’S

WHAT IS IT ?WHAT IS IT ?

BIOMECHANICS is the study of the scientific principles which BIOMECHANICS is the study of the scientific principles which contribute to human movementcontribute to human movement

BIOMECHANICS studies the internal forces (generated by BIOMECHANICS studies the internal forces (generated by muscles, tendonsmuscles, tendons)) and the external forces (gravity, and the external forces (gravity, resistance) acting on a human bodyresistance) acting on a human body

WHAT IS BIOMECHANICS?

Michael Johnson

BIOMECHANICSWHAT IS THE IDEAL IN CRICKET ?WHAT IS THE IDEAL IN CRICKET ?

BATTING :BATTING :To hit the ball hard (i.e. To hit the ball hard (i.e. powerpower), ), where we want to (i.e. where we want to (i.e. controlcontrol).).

BOWLING :BOWLING :To bowl / spin the ball fast (To bowl / spin the ball fast (powerpower), ), land it where we want (land it where we want (controlcontrol), ), with the variations we want (with the variations we want (controlcontrol).).

FIELDING :FIELDING :To gather the ball cleanly (To gather the ball cleanly (controlcontrol) and throw it ) and throw it

quickly (quickly (powerpower) ) andand accurately ( accurately (controlcontrol))

““Players with sound biomechanics are able to perform Players with sound biomechanics are able to perform skills efficiently, with minimum fatigue or injury”skills efficiently, with minimum fatigue or injury”

INTRODUCING BIOMECHANICS TO THE PLAYER

It is natural for…It is natural for… AAllll A Athletes to thletes to AAim for im for AAchievementchievement

““I’ve always done it like this”I’ve always done it like this”““How much cricket have you played”How much cricket have you played”

““Just fix it up”Just fix it up”““I just want to bowl faster”I just want to bowl faster”

““Why should I ?”Why should I ?”

INTRODUCING BIOMECHANICS TO THE COACH

CCoaches oaches CCoach oach CCausesauses Coaches must correct the cause not the Coaches must correct the cause not the

symptomsymptom Coaches need to understand the:Coaches need to understand the:

When, When, How, and How, and Why, of all movementsWhy, of all movements

THE CENTRAL THEME OF BIOMECHANICS

BALANCEAND

STABILITY

POWER CONTROL

• Moment of Inertia• Momentum• Lever alignment• Force summation

• Momentum• Lever alignment• Force summation

BALANCE AND

STABILITY

BIOMECHANICS - CENTRAL THEME

POWER CONTROL

“provides”

THE LANGUAGE OF BIOMECHANICS

For the purposes of clear communication, For the purposes of clear communication, coaches must understand BALANCE and coaches must understand BALANCE and STABILITY are interchangeable terms…STABILITY are interchangeable terms…

…“…“to keep in equilibrium” …to keep in equilibrium” ……“…“the maintenance of equilibrium” …the maintenance of equilibrium” …

Definitions from The Concise Oxford DictionaryDefinitions from The Concise Oxford Dictionary

STABILITY PRINCIPLESA body is A body is balancedbalanced when its when its centre of gravitycentre of gravity is is verticallyvertically within its within its

base of supportbase of support

Base of support

Centre of gravity outside base of support - fall over

A body A body loses balanceloses balance when its centre of gravity is vertically when its centre of gravity is vertically outsideoutside its its base of supportbase of support

STABILITY PRINCIPLES

The wider the base of support, the greater the stability

The narrower the base of support, the greater the instability

Balance can involve a fixed baseBalance can involve a fixed base ( (static balance)static balance),,

STABILITY PRINCIPLES

or maintaining body control during movementor maintaining body control during movement ((dynamic balancedynamic balance))

A body A body loses balanceloses balance when its centre of gravity is vertically when its centre of gravity is vertically outsideoutside its its base of supportbase of support

STABILITY PRINCIPLES

STABILITY - BATTINGSTANCESTANCE

The line of gravity is over the centre of the feetThe line of gravity is over the centre of the feet

ALIGNMENTALIGNMENTThe base of support is aligned with the intended generation of forceThe base of support is aligned with the intended generation of force

THE STEPTHE STEPThe LOWER the centre of gravity, the GREATER the stabilityThe LOWER the centre of gravity, the GREATER the stability

The wider the base of support, the GREATER the stabilityThe wider the base of support, the GREATER the stability

STABILITY - BATTING

A STABLE BASE enables FULL FORCE GENERATIONA STABLE BASE enables FULL FORCE GENERATION

The bat starts to move FORWARD only after the front FOOT has made CONTACT with The bat starts to move FORWARD only after the front FOOT has made CONTACT with the GROUNDthe GROUND

The legs remain BRACED to ensure maximum force generationThe legs remain BRACED to ensure maximum force generation

STABILITY

Spinners use shorter delivery stride lengths to increase height at releaseSpinners use shorter delivery stride lengths to increase height at release

Delivery strides too long - loss of height and leg collapseDelivery strides too long - loss of height and leg collapse

STABILITY - BOWLING

Changing the line of gravity may be used to Changing the line of gravity may be used to initiate movementinitiate movement

Head to ball when stepping forwardHead to ball when stepping forward

Leaning forward to begin run upLeaning forward to begin run up

STABILITY – DYNAMIC BALANCE

STABILITY - FIELDINGFielding requires a “trade off” between Fielding requires a “trade off” between

stability required to generate the necessary forces to move to the ball,stability required to generate the necessary forces to move to the ball,

andand

instability which assists movement towards the ball (e.g. initiating instability which assists movement towards the ball (e.g. initiating lateral movement is difficult if the fielder is too stable)lateral movement is difficult if the fielder is too stable)

Base of support too narrow Base of support allows lateral movement

Base of support too wide Base of support too wideBalanced “jump step”

STABILITY - CONSEQUENCESBalance is affected when any body part is moved away from the Balance is affected when any body part is moved away from the centre of gravitycentre of gravity

balance is lost, or compensation must occurbalance is lost, or compensation must occur the further the bat is from the body, the harder it is to move or the further the bat is from the body, the harder it is to move or

control ( it “controls” you rather than you “controlling” it )control ( it “controls” you rather than you “controlling” it )

Hands away from body in the backlift

STABILITY - CONSEQUENCESBalance is affected when any body part is moved away from the Balance is affected when any body part is moved away from the centre of gravitycentre of gravity

balance is lost, or compensation must occurbalance is lost, or compensation must occur the further the ball is from the body, the harder it is to move or the further the ball is from the body, the harder it is to move or

control ( it “controls” you rather than you “controlling” it )control ( it “controls” you rather than you “controlling” it )

Ball away from body - balance and efficiency compromisedBall away from body - balance and efficiency compromised

STABILITY

A stable base ensures :A stable base ensures : the eyes are still, so perception is enhancedthe eyes are still, so perception is enhanced there is a resistance to work the body levers againstthere is a resistance to work the body levers against body energy is transferred efficiently to the bat / ballbody energy is transferred efficiently to the bat / ball

SUMMARY OF STABILITY PRINCIPLES

1. Optimum stability occurs when the centre of gravity is centrally located over the base of support.

2. The lower the centre of gravity, the greater the stability.

3. The wider the base of support, the greater the stability. This needs to be kept in proportion. A base of support too great will impair vital movements.

4. Greater stability occurs when the base of support is aligned with the oncoming force and the intended target

5. Forces can be progressively increased if the body provides a stable base of support.

6. A stable base ensures :• the eyes are still, so perception is enhanced• there is a resistance to work the body levers against• body energy is transferred efficiently to the bat / ball

7. Moving any body part outside of the base of support affects balance

PART “B”

EXTENSIONSEXTENSIONS

“These principles have a more scientific origin. Coaches should have a basic understanding of how they impact on cricket performance”

OTHER PRINCIPLES OF BIOMECHANICS

MOMENT OF INERTIAMOMENT OF INERTIA MOMENTUMMOMENTUM LEVER ALIGNMENTLEVER ALIGNMENT FORCE SUMMATIONFORCE SUMMATION

INERTIA

INERTIA is INERTIA is thethe tendency of a body to maintain its tendency of a body to maintain its present state of motionpresent state of motion

if a body is stationary, it will remain that way unless if a body is stationary, it will remain that way unless acted on by an outside force.acted on by an outside force.

if a body is moving it will tend to keep moving, unless if a body is moving it will tend to keep moving, unless acted on by an outside force.acted on by an outside force.

The greater a body’s MASS, the greater its INERTIAThe greater a body’s MASS, the greater its INERTIA

In cricket, the player must overcome the inertia of the In cricket, the player must overcome the inertia of the bat or ball to generate bat or ball speedbat or ball to generate bat or ball speed … …

… … In other words the player must be able to control In other words the player must be able to control the movement of the bat or ballthe movement of the bat or ball

LEVERAGE - MOMENT OF INERTIA“ “ EASE OF TURNING ”EASE OF TURNING ”

MOMENT OF INERTIA is the tendency of a body to maintain its present state of MOMENT OF INERTIA is the tendency of a body to maintain its present state of “angular” motion (ROTATION)“angular” motion (ROTATION)

In angular motion, the ability of an object to turn depends not only on its mass, but In angular motion, the ability of an object to turn depends not only on its mass, but on how far this mass is distributed from the axis of rotationon how far this mass is distributed from the axis of rotation

Moment of Inertia Moment of Inertia == Mass x Radius Mass x Radius 22

I I = mr = mr 22

The greater the moment of inertia, the harder it is to start movingThe greater the moment of inertia, the harder it is to start moving

radius is smaller - easier to turn

radius is larger - harder to turn

LEVERS play an important role in movement by maximizing speed and/or force LEVERS play an important role in movement by maximizing speed and/or force of movementof movement

The muscles, tendons and bones of the body work together as leversThe muscles, tendons and bones of the body work together as levers

LEVERAGE - MOMENT OF INERTIA

LEVERAGE - MOMENT OF INERTIAIt is easier to move a short lever than a long lever of the same mass

SHORTER levers can be used to increase SPEED with less effort

This is why the BAT should be in CLOSE to the body so that it is easier to swing with POWER and CONTROL

LEVERAGE - MOMENT OF INERTIAIt is easier to move a short lever than a long lever of the same mass

SHORTER levers can be used to increase SPEED with less effort

This is why BOWLERS should fold their arms and front leg in CLOSE to their body to optimise their STABILITY to deliver the ball with POWER and CONTROL

MOMENTUM

MOMENTUMMOMENTUM == Mass x Velocity Mass x Velocity (Speed)(Speed)

MM == mvmv

• The greater the mass, the greater the momentum

• The greater the velocity, the greater the momentum

• Compare tennis ball to shot put, toy car to motor car

IMPULSE

IMPULSE IMPULSE = = CHANGE IN MOMENTUMCHANGE IN MOMENTUMF.t F.t = = mvmv2 2 - mv- mv11

The aim in cricket is to maximize the change in momentum of the bat or ball

This achieved by increasing the forces and/or increasing the time the forces act

IMPULSEIncreasing the TIME over which a constant force operates increases the Increasing the TIME over which a constant force operates increases the

IMPULSE (change in momentum)IMPULSE (change in momentum)

Batters should take a FULL STEP to increase stability and flatten the downswing arcBatters should take a FULL STEP to increase stability and flatten the downswing arc

The LEAN BACK position for side on bowlers increases the TIME over which the forces may The LEAN BACK position for side on bowlers increases the TIME over which the forces may be generatedbe generated

IMPULSE IMPULSE IMPULSE = = CHANGE IN MOMENTUMCHANGE IN MOMENTUM

““SOFT” HANDSSOFT” HANDS

By increasing the length of catch, the time increases, so the force is reducedBy increasing the length of catch, the time increases, so the force is reduced

IMPULSEFlattening the arc of the downswing increases speed and controlFlattening the arc of the downswing increases speed and control

The wrists move FORWARD during the impact phaseThe wrists move FORWARD during the impact phase

IMPULSE - SUMMARY

ABSORBING FORCESABSORBING FORCES To reduce the impact of a catch To reduce the impact of a catch oror To absorb the forces of the follow through (batting and To absorb the forces of the follow through (batting and

bowling)bowling)…… a player can a player can increaseincrease the the

TTIME to absorb force IME to absorb force RRANGE of movement to absorb force ANGE of movement to absorb force AAREA to absorb forceREA to absorb force MMASS to absorb forceASS to absorb force

LEVER ALIGNMENT - BATTINGIt is important to align the body levers with the oncoming ball to ensure the It is important to align the body levers with the oncoming ball to ensure the maintenance of vertical bat swing that allows the player to hit the ball with maintenance of vertical bat swing that allows the player to hit the ball with POWER and CONTROLPOWER and CONTROL

Shoulders should be rotated slightly FORWARD by the TOP of the backswingShoulders should be rotated slightly FORWARD by the TOP of the backswing

The front elbow sets the line for the arm levers – extend arms towards the targetThe front elbow sets the line for the arm levers – extend arms towards the target

LEVER ALIGNMENT - BOWLING It is important to keep all body levers moving in the line of the target to ensure It is important to keep all body levers moving in the line of the target to ensure

a balanced delivery and efficient generation of POWER and CONTROLa balanced delivery and efficient generation of POWER and CONTROL

Poor lever alignment produces inconsistent performancesPoor lever alignment produces inconsistent performances

LEVER ALIGNMENT - SUMMARYKeep all body levers moving along the target line to Keep all body levers moving along the target line to maximise POWER and CONTROLmaximise POWER and CONTROL

BattingBatting step at targetstep at target rotate shoulders in direction of targetrotate shoulders in direction of target align front elbow with targetalign front elbow with target

BowlingBowling pump elbows down target line in run uppump elbows down target line in run up keep ball in close to body planekeep ball in close to body plane drag front elbow down target linedrag front elbow down target line rotate shoulders vertically towards targetrotate shoulders vertically towards target

“Direct the energy / core of the body at the target”

FORCE SUMMATION - BATTINGLarge muscles move FIRST, then STABILIZE so that the NEXT SMALLER Large muscles move FIRST, then STABILIZE so that the NEXT SMALLER muscle group is able to ACCELERATE, therefore ADDING SPEED to the BAT muscle group is able to ACCELERATE, therefore ADDING SPEED to the BAT as it gets closer to impact.as it gets closer to impact.

FORCE SUMMATION – BATTING (example)

THE 6 S’s of BATTINGTHE 6 S’s of BATTING SET UPSET UP

• head over feet, hands in closehead over feet, hands in close• levers lined up, shoulders slightly openlevers lined up, shoulders slightly open

STEPSTEP• move the body mass towards the impact pointmove the body mass towards the impact point

STOP or STABILISESTOP or STABILISE• firm up the base and use as a secure anchor / pivot pointfirm up the base and use as a secure anchor / pivot point

SWINGSWING• rotate the shoulders into the ball, maintain “9”rotate the shoulders into the ball, maintain “9”

SHOULDERSSHOULDERS• concentrate on the shoulders and the arms will followconcentrate on the shoulders and the arms will follow

STRAIGHTSTRAIGHT• step, backswing, downswing, and bat all move straight to impact pointstep, backswing, downswing, and bat all move straight to impact point

FORCE SUMMATION - BOWLINGLARGE muscles move FIRST, then STABILIZE so that the NEXT SMALLER LARGE muscles move FIRST, then STABILIZE so that the NEXT SMALLER muscle group is able to ACCELERATE therefore ADDING SPEED to the BALL muscle group is able to ACCELERATE therefore ADDING SPEED to the BALL as it gets closer to releaseas it gets closer to release

Legs absorb, then lock, then front elbow “cracks the whip”Legs absorb, then lock, then front elbow “cracks the whip”

LOCK UPLOCK UP““CRACK THE WHIP”CRACK THE WHIP”

FORCE SUMMATION - BOWLING

FORCE SUMMATION - SUMMARYUse large body parts to commence movement, then lock them Use large body parts to commence movement, then lock them to accelerate smaller body parts sequentiallyto accelerate smaller body parts sequentially

BattingBatting Release bottom hand by top of backliftRelease bottom hand by top of backlift Complete step before starting downswing Complete step before starting downswing Brace knees during downswingBrace knees during downswing Keep feet still during downswing – hips must uncoil off a stable Keep feet still during downswing – hips must uncoil off a stable

basebase Rotate shoulders, arms and bat down to impact in the same planeRotate shoulders, arms and bat down to impact in the same plane Wrists unlock when shoulders slow down and stabiliseWrists unlock when shoulders slow down and stabilise

“Everything starts from the ground, through the base, through the body core, then through the arms”

Use large body parts to commence movement, then lock them Use large body parts to commence movement, then lock them to accelerate smaller body parts sequentiallyto accelerate smaller body parts sequentially

BowlingBowling Foot imprint in line with the targetFoot imprint in line with the target Head steady with eyes levelHead steady with eyes level Arms rotate close to body and in line with the targetArms rotate close to body and in line with the target Knees absorb impact then stabiliseKnees absorb impact then stabilise Front elbow locks as bowling arm reaches the horizontalFront elbow locks as bowling arm reaches the horizontal Arms and shoulders rotate as vertically as possibleArms and shoulders rotate as vertically as possible

“Everything starts from the ground, through the base, through the body core, then through the arms”

FORCE SUMMATION - SUMMARY

SUMMARY

““THE BOTTOM LINE”THE BOTTOM LINE”

OPTIMIZES PERFORMANCEOPTIMIZES PERFORMANCE

PREVENTS INJURYPREVENTS INJURY

B IOMECHAN ICS

HELPS ATHLETESUNDERSTAND WHY

PROVIDES PRINCIPLESPROVIDES PRINCIPLES

PROVIDES SYSTEMATICPROVIDES SYSTEMATICBASIS FOR PROBLEM BASIS FOR PROBLEM SOLVINGSOLVING

B IOMECHAN ICS

PRODUCES MOREEFFECTIVEPLAYERS

EXPLAINS WHYEXPLAINS WHY

ELIMINATES GUESSWORKELIMINATES GUESSWORK

IS MORE EFFICIENTIS MORE EFFICIENT

FOCUSES ON BASICSFOCUSES ON BASICS

B IOMECHAN ICS

PRODUCES MOREEFFICIENTPLAYERS

SIMPLIFIESSIMPLIFIES

IS CONSISTENTIS CONSISTENT

PRIORITIZESPRIORITIZES

ALLOWS INDIVIDUALITYALLOWS INDIVIDUALITY

B IOMECHAN ICS

PRODUCES CONSISTENT

PERFORMANCES

BIOMECHANICSBIOMECHANICS

DETERMINESDETERMINESPRODUCESPRODUCESGOVERNSGOVERNS

CONTROLSCONTROLSTECHNIQUETECHNIQUE

&&

SKILLSKILL

CONSISTENT PLAYERCONSISTENT PLAYERPERFORMANCEPERFORMANCE

TEACHINGMETHOD

COACHINGMETHOD

THE K.I.S.S. PRINCIPLE

Biomechanics helps toBiomechanics helps to

KKEEPEEP

IITTSSUPERUPER

SSIMPLEIMPLE