Transcript
PACE BOWLING
“Fast bowling is an exciting part of our game. It is also a strenuous activity that places bowlers at risk to injury. Fast bowlers who try to bowl too fast, for too long, at a young age increase the chances of injury occurring.”
D. K. LilleeD. K. Lillee
INTRODUCTION
AIM
To provide you with the knowledge and understanding of the guiding principle(s) of fast bowling, allowing you to assist bowlers in the everyday coaching environment.
K.I.S.S. Principle
Keep It Super Simple
FORCE ABSORPTIONFORCE ABSORPTION
STABILITYSTABILITY
ALIGNMENTALIGNMENT
MOMENTUMMOMENTUM
Change focus to efficiency based on sound biomechanical principles
PRINCIPLES OF PACE BOWLING
FORCE ABSORPTIONFORCE ABSORPTION
STABILITYSTABILITY
ALIGNMENTALIGNMENT
MOMENTUMMOMENTUM
Focus on ‘WHAT TO DO’ rather than on what ‘NOT’ to do
PRINCIPLES OF PACE BOWLING
FORCE ABSORPTIONFORCE ABSORPTION
STABILITYSTABILITY
ALIGNMENTALIGNMENT
MOMENTUMMOMENTUM
PRINCIPLES OF PACE BOWLING
to develop and maintain all body to develop and maintain all body movements in the direction of the batsmanmovements in the direction of the batsman
to ensure hips and shoulders face in the to ensure hips and shoulders face in the same direction at back foot landingsame direction at back foot landing
to maintain balance and support throughout to maintain balance and support throughout the delivery stridethe delivery stride
to reduce and release the stresses to reduce and release the stresses produced during run-up and deliveryproduced during run-up and delivery
Wasim, “Maco” & “DK”
SPOTPROGRAM
SPOT PROGRAM
Four key components:- S creening
- P hysical preparation
- O verbowling
- T echnique
SPOT Booklet was the first publication of the Injury Prevention Strategy (May 1993 / revised October 1998)
Basis for continuing publications, research and injury prevention programs
SPOT Poster
SPOT POSTER
SPOT POSTER
SPOT POSTER
SPOT POSTER
SPOT – SCREEN FOR RISK FACTORS
A number of factors can increase the risk of injury, particularly for developing fast bowlers (teenage years onwards)
Bodyweight problems Postural defects Everyday lifestyle Body development
SPOT – PHYSICAL PREPARATION
Appropriate physical preparation is important from injury prevention and optimum performance perspectives. Physical preparation programs should be designed by a fitness professional to suit the individual needs of bowlers and the specific demands of fast bowling.
Fitness programs should include the following components:
- Strength & Power (including trunk/core)
- Endurance and Interval Training
- Flexibility
- Education regarding Warming Up and Cooling Down These aspects of a fast bowlers fitness should be routinely monitored
SPOT – OVERBOWLING
Young pace bowlers should not be over bowled. Factors such as physical maturity, bowling speed and effort and playing conditions will determine the appropriate workload. The table below shows the maximum recommended overs for practice and matches under normal circumstances.
** break between spells to be 60 min or longer
* substitute one practice session / additional match played in the week
SPOT – TECHNIQUE
GOOD TECHNIQUE IS IMPORTANT, NOT ONLY FOR SKILL, BUT ALSO FOR REDUCING STRESS PLACED ON THE BODY
“FAST BOWLING, REGARDLESS OFTECHNIQUE,
HAS AN INHERENT RISK OF INJURY”
SPOT – TECHNIQUE – The Side-on Set up
At back foot landing the foot, hips and shoulders are side-on
The bowler looks “through” the front arm
SPOT – TECHNIQUE – Side-on Set up
SPOT – TECHNIQUE – The Front-on Set up
The bowler lands with his back foot pointing somewhere between mid-wicket and the batter
The hips and shoulders are open at back foot contact
The bowler looks at the target just inside the front arm
It is important the front-on bowler stays front-on throughout the full delivery stride
SPOT – TECHNIQUE – Front-on Set up
SPOT – TECHNIQUE – Front-on Set up
Some important points:
Generally approach the wicket faster as they do not have the
shoulder rotation between BFI and ball release that side-on
bowlers do
Generally successful front-on bowlers will use shorter levers
SPOT – TECHNIQUE – Front-on Set up
A fully front-on technique does exist but is rare in Australia. There is more of a tendency for this to occur in the Caribbean.
In most coaching programs the front-on technique has been redefined:
Front-on for the very “open-chested”
Semi-open for the more closed orientation but not side-on bowler
SPOT – TECHNIQUE – Front-on v Semi-open
SPOT – TECHNIQUE – Semi-open Set up
COMMON PROBLEMS WITH PACE BOWLING TECHNIQUE
COMMON PROBLEMS – The Mixed Set-up
Has been statistically linked to a higher incidence of
lower back stress fractures, bony abnormalities and
soft tissue injuries
COMMON PROBLEMS – The Mixed Set-up
Includes a range of mal-aligned setup postures at Back Foot Impact (BFI)
COMMON PROBLEMS – The Mixed Set-up
An example:
Trying to be Side-on
Shoulders not aligned at BFI
COMMON PROBLEMS – Counter-rotation
Counter-rotation is a movement of the shoulders (from an aligned set-up
or a mixed set-up) to a more side on position during the delivery stride
COMMON PROBLEMS – Counter-rotation
Shoulders become
more side on
COUNTERROTATION IS A MOVEMENT OF THE SHOULDERS TO A MORE SIDE ON POSITION RELATIVE TO THE HIPS DURING THE DELIVERY STRIDE
FROMShoulders front onat back foot landing
TOShoulders side on
during delivery stride
An example:
COMMON PROBLEMS – Counter-rotation
Shoulder counter-rotation = 35 degrees
COMMON PROBLEMS – Counter-rotation
It is the number ONE known technique link to lower back stress fractures
It may affect bowling accuracy
It can lead to hyperextension and lateral flexion
It is inefficient - the shoulders are rotating across the target line
It’s hard for the coach to detect without high quality slow motion video
COMMON PROBLEMS – Hyperextension
Hyperextension is an arching of the spine backwards at back
foot landing, during the delivery stride, or at front foot landing
COMMON PROBLEMS – Hyperextension
An example:
TECHNIQUE & INJURY
TECHNIQUE & INJURYWhat causes Common Problems with PaceBowling Technique? Momentum heading in the wrong direction Poor stability Inappropriate load-up position Long bowling arm in down phase Too open in Shoulders at BFI Inefficient Front-arm? Coaching history - Side-on Game!! Idol modeling Low Strength v Optimal v High Strength Flexibility and Front-on v Semi-Open
TECHNIQUE & INJURY
The Research
University of Western Australia
University of Queensland
Australian Cricket Board
Australian Institute of Sport
United Kingdom
New Zealand
South Africa
TECHNIQUE & INJURY
What the AIS Research Says
42 Fast Bowlers 1996 - 1999
Complete 3-D technique and Injury History
4 Injury Groups :
Stress Fracture Lower BackSoft Tissue Lower Back
Trunk Side StrainNo Trunk Injury
TECHNIQUE & INJURYCounter-rotation of shoulders after reasonable alignment at BFI
characteristic of stress fracture group
TECHNIQUE & INJURY
TECHNIQUE & INJURY
TECHNIQUE & INJURY
TECHNIQUE & INJURY
TECHNIQUE & INJURY
What’s so bad about Shoulder Counter-Rotation?
It’s inefficient - the shoulders are rotating away from the batsmen. The “degrees of freedom” are increased
Because the hips are usually starting to open when it happens the torsion in the lower back is increased significantly
It can cause the bowler to hyper-extend and hyperflex the trunk at FFC (4 - 10 x Body Weight) – Burnett et al., 1998 have provided some initial support for this
LOAD UP
LONG v SHORT LEVERS – NOT ALWAYS BLACK & WHITE
Long Levers versus Short LeversIncreased moment of inertia Decreased moment of inertia
More energy required Less energy required
Mixed at BFI Aligned at BFI
LOAD UPS & LEVERAGE
Individuality needs to be considered
LOAD UPS & LEVERAGEIndividuality needs to be considered
LOAD UPS & LEVERAGE
Individuality needs to be considered
RUN UP PHASE
GATHER PHASE
BACK FOOT IMPACT
DELIVERY STRIDE
RELEASE PHASE
FOLLOW THROUGH
PHASES OF THE BOWLING ACTION
ARM AND HAND MOVEMENT
Parallel to the target line, elbows bent at 90 degrees
Pump the elbows straight back
STRIDE BUILD UP
Forward body lean with short steps initially, building into longer steps
A balanced running stride prior to take off
RUN UP PHASE
FRONT ARM PATHWAYThe front arm should move
straight up, parallel to the target line, not too far across the body
BOWLING ARM The bowling arm should move in
a plane parallel to the target line
APPROACHMaintain a line to and through the crease, along the target line.
The back leg should come through “searching” for the ground in front of the body
GATHER PHASE
BOWLING ARM Bowling arm should be moving
in a plane parallel to the target line
FRONT ARM
The front arm should move straight up, parallel to the target line, not too far across the body
Eyes should be looking through or just inside the front arm
HIP AND SHOULDER ALIGNMENT
Hips and shoulders should be aligned in the same plane at back
foot impact
LEG MECHANICS
Back leg should land bent and straighten through the delivery
stride
Front leg should be moving towards the target line, not
across the body
BACK FOOT IMPACT
SHOULDER & HIP ALIGNMENT
There should be minimal closing of the shoulders after back foot impact
Some closing (counter rotation) occurs in nearly all bowlers
BOWLING ARMBowling arm should move in a
plane parallel to the target line from top of the shoulder, past hip
and around
FRONT ARMShould come straight down, bent
and lock into front hip, before extending straight back after
release
LEG MECHANICSThe front leg should land in a straight line towards the target line, providing a balanced platform to work the upper
body from
DELIVERY STRIDE
LEG MECHANICSThe front leg should land slightly bent and straighten to lock up just
prior to release. The back leg should come straight through along the target line, bending the knee to
lift “up and over” an imaginary obstacle beside the front foot
BOWLING ARMRelease point should be directly
above the bowling side hip. Follow through should be past the
non bowling side thigh
HEAD POSITIONThe head should be kept as still
and as level as possible
FRONT ARMThe front arm elbow should be locked into the front hip with the hand in a “handshake” position
down the target line
RELEASE PHASE
The follow through is a product of movements that occur earlier in the delivery. When analysing
actions, look for “causes” in early stages of the delivery rather than the “symptoms”, that usually present in the release and follow through phases.
Remember …
“Prevention is better than the cure”
FOLLOW THROUGH
REMEDIAL DRILLS
Habit forming
Repetition for reinforcement
Rehabilitation aid
Provides instant feedback
Not “coach” intensive
REMEDIAL DRILLS
RUN UP Drill 1: efficient forward momentum with all body movements
towards the target and forward body lean Drill 2: produce a suitable length run-up for the individual
GATHER Drill 1: all body movements continue towards the target
throughout delivery Drill 2: extension of gather drill 1, with the addition a physical
obstruction (e.g. stumps)
REMEDIAL DRILLS
BACK FOOT LANDING Drill 1: timing of the gather of the bowling hand outside the
chin at back foot landing
DELIVERY STRIDE Drill 1: application of the ‘double pendulum’ model using
‘scrunchie’ to assist
Drill 2: demonstrate the hand/ ball speed that can be generated utilising the ‘double pendulum’ model
REMEDIAL DRILLS
RELEASE Drill 1: ensure bowler achieves vertical hip and shoulder rotation Drill 2: ensure bowler achieves vertical hip/ shoulder rotation
and the best release point Drill 3: develops a powerful straightening of the back leg which
assists forward momentum and increases the height of release
FOLLOW THROUGH Drill 1: develops a powerful straightening of the back leg which
assists forward momentum and increases the height of release
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