this achievement standard requires demonstration of understanding of functional anatomy and...
TRANSCRIPT
This achievement standard This achievement standard requires demonstration of requires demonstration of
understanding of functional understanding of functional anatomy and anatomy and biomechanical biomechanical
principles and how they relate to principles and how they relate to physical activity, through physical activity, through
participation and/or observationparticipation and/or observation
Learning IntentionLearning Intention
To understand what Biomechanics is To understand what Biomechanics is and how it can be applied to and how it can be applied to Badminton.Badminton.
To develop an understanding of the To develop an understanding of the key aspects of Biomechanics as part key aspects of Biomechanics as part of the learning process.of the learning process.
Defining Biomechanics Defining Biomechanics
Bio = body Mechanics = forces and Bio = body Mechanics = forces and motionmotion
““Biomechanics is the science Biomechanics is the science concerned with how forces concerned with how forces
(internal & external) act on the (internal & external) act on the human body and the effects human body and the effects
these forces have on the motion these forces have on the motion of the bodyof the body”.”.
WHAT IS BIOMECHANICS?WHAT IS BIOMECHANICS?
It involves the study of It involves the study of ForcesForces and and MotionMotion involved in human movement, involved in human movement, particularly sport performance. particularly sport performance.
In other words, biomechanics looks at In other words, biomechanics looks at what is the best technique for generating what is the best technique for generating forces and producing the most efficient forces and producing the most efficient motion, in order to maximise sport motion, in order to maximise sport performance (performance (techniquetechnique). ).
QUESTION????QUESTION????
What is the best way to What is the best way to kick a rugby ball?, hit a kick a rugby ball?, hit a golf ball?, throw a golf ball?, throw a softball?, shoot a softball?, shoot a basketball?, hit a tennis basketball?, hit a tennis ball?ball?
FORCESFORCES
ForceForce = = “is a “is a push or pull that push or pull that changes a body's changes a body's state of rest or state of rest or motion”.motion”.
Internal ForcesInternal Forces – – generated within generated within the body e.g.. the body e.g.. forces due to forces due to muscle muscle contractioncontraction
External Forces – External Forces – acting outside acting outside from the body from the body e.g.. gravitye.g.. gravity
FORCESFORCES In sport athletes primarily produce force within In sport athletes primarily produce force within
the body by contracting the musclesthe body by contracting the muscles..
Types of ForcesTypes of ForcesMuscularMuscular
GravitationalGravitationalFrictionalFrictional
AerodynamicAerodynamic Contact (ground or another body), Contact (ground or another body),
InertialInertialElasticElastic
CentripetalCentripetalCentrifugalCentrifugal
TYPES OF FORCESTYPES OF FORCES Muscular ForceMuscular Force = due to the = due to the
contraction of muscle.contraction of muscle.
Friction ForceFriction Force = due to two = due to two surfaces in contact with each other surfaces in contact with each other and the tendency of the two surfaces and the tendency of the two surfaces to oppose each others motion e.g.. to oppose each others motion e.g.. mountain bike vs. racing bike tyres, mountain bike vs. racing bike tyres, sports shoe soles for various sportssports shoe soles for various sports,,
Gravity Gravity = is the downward acting = is the downward acting force which attracts bodies to the force which attracts bodies to the centre of the earth.centre of the earth.
Aerodynamic ForceAerodynamic Force = (is a type of = (is a type of frictional force) due to air resistance, frictional force) due to air resistance, where particles of air resist the motion where particles of air resist the motion of a body through it. e.g.. use of aero of a body through it. e.g.. use of aero bars for cycling, spin in a tennis serve, bars for cycling, spin in a tennis serve, swing in bowling a cricket ballswing in bowling a cricket ball
ContactContact = the force involved in a = the force involved in a collision of bodies or the ground. e.g.. collision of bodies or the ground. e.g.. Scrum or Tackling collisions in rugby, Scrum or Tackling collisions in rugby, hitting or catching a cricket ball, hitting or catching a cricket ball, runningrunning
Inertia Inertia = the force of an object due to = the force of an object due to its mass (whether moving or stationary)its mass (whether moving or stationary)
e.g.. catching a medicine ball vs. e.g.. catching a medicine ball vs. catching a volleyball, catching a cricket catching a volleyball, catching a cricket vs. tennis ballvs. tennis ball
CentripetalCentripetal = = force which is force which is directed in toward directed in toward the central axis of the central axis of a rotating body.a rotating body.
CentrifugalCentrifugal = = force directed force directed outward away from outward away from the central axis of the central axis of a rotating body.a rotating body.
TaskTask
For each of the following, identify the For each of the following, identify the forces acting and what or who they are forces acting and what or who they are acting on.acting on. Kicking a soccer ballKicking a soccer ball Tennis serveTennis serve Throwing a javelinThrowing a javelin A rugby tackleA rugby tackle Hitting a ball in cricketHitting a ball in cricket Catching a medicine ballCatching a medicine ball Somersault in gymnasticsSomersault in gymnastics
Newton’s First LawNewton’s First Law
The Law of InertiaThe Law of Inertia
(The 1st Law of (The 1st Law of Motion)Motion)
Newton's First Law of MotionNewton's First Law of Motion - - The Law of InertiaThe Law of Inertia
A body will remain in a state of rest A body will remain in a state of rest or in uniform straight line motion, or in uniform straight line motion, unless acted upon by a force to unless acted upon by a force to change that state of rest or motionchange that state of rest or motion”.”.
e.g.. e.g.. Daniel Carter kicking a goal ball will Daniel Carter kicking a goal ball will remain at rest until Dan applies a force remain at rest until Dan applies a force with his foot. The ball would travel in a with his foot. The ball would travel in a straight line into the sky, but is acted upon straight line into the sky, but is acted upon by gravity and air resistance (wind) to by gravity and air resistance (wind) to change its motion change its motion
Newton's First Law of MotionNewton's First Law of Motion - - The Law of InertiaThe Law of Inertia
Moving InertiaMoving Inertia An object in motion tends to remain in An object in motion tends to remain in
motion and to travel in a straight line motion and to travel in a straight line with uniform velocity unless acted with uniform velocity unless acted upon by some external force.upon by some external force.
Stationary InertiaStationary Inertia An object at rest tends to remain at An object at rest tends to remain at rest unless acted upon by some rest unless acted upon by some external force.external force.
Newton's First Law of MotionNewton's First Law of Motion - - The Law of InertiaThe Law of Inertia
InertiaInertia
In order to set in motion a body presently at In order to set in motion a body presently at rest, you need to overcome the tendency of rest, you need to overcome the tendency of the body to remain at rest. This tendency of the body to remain at rest. This tendency of the body to remain at rest is called it's the body to remain at rest is called it's stationary inertiastationary inertia. The applied force must . The applied force must overcome the body's stationary inertia for overcome the body's stationary inertia for motion to occur. If the force is not great motion to occur. If the force is not great enough to overcome the body's stationary enough to overcome the body's stationary inertia the body will remain at rest.inertia the body will remain at rest.
InertiaInertia
A very heavy Barbell has stationary A very heavy Barbell has stationary inertia, A large force overcomes this inertia, A large force overcomes this and action occurs. The heavier and action occurs. The heavier barbell has greater stationary inertia, barbell has greater stationary inertia, force cannot overcome this, motion force cannot overcome this, motion does not occur and barbell remains does not occur and barbell remains at rest.at rest.
InertiaInertia
An object in motion tends to remain in An object in motion tends to remain in motion and this tendency is called motion and this tendency is called
the body's the body's moving inertiamoving inertia. .
A force must overcome the body's A force must overcome the body's moving inertia in order to alter the moving inertia in order to alter the
body's motion. body's motion.
The motion of the basketball is altered, The motion of the basketball is altered, i.e. the ball is deflected when a force i.e. the ball is deflected when a force
is applied by the hand.is applied by the hand.
TaskTask
Passing and catching different sized Passing and catching different sized medicine ballsmedicine balls
Why is more force required to move Why is more force required to move the larger mass medicine ball?the larger mass medicine ball?
List 3 examples where the principals List 3 examples where the principals of stationary inertia and moving of stationary inertia and moving inertia are important aspects of the inertia are important aspects of the sportsport
NEWTONS 3 LAWS OF MOTIONNEWTONS 3 LAWS OF MOTION
The Law of The Law of AccelerationAcceleration
(The 2nd Law of (The 2nd Law of Motion)Motion)
Newton's Second Law of MotionNewton's Second Law of Motion = =
TThe Law of Accelerationhe Law of Acceleration The acceleration (change in motion) of The acceleration (change in motion) of
a body is proportional to the force a body is proportional to the force causing it, and the change takes place causing it, and the change takes place in the direction that the force acts.in the direction that the force acts.
Newton's Second Law of Motion, the Newton's Second Law of Motion, the law of acceleration can be expressed law of acceleration can be expressed as: as:
Acceleration = force / massAcceleration = force / mass
Newton's Second Law of MotionNewton's Second Law of Motion = = TThe Law of Accelerationhe Law of Acceleration
When a body is acted upon by a When a body is acted upon by a force......force......
The greater the force, the greater The greater the force, the greater the the acceleration.acceleration.
The smaller the mass, the greater The smaller the mass, the greater the the acceleration.acceleration.
The change in motion takes place The change in motion takes place in in the direction in which the force is the direction in which the force is
applied.applied.
NEWTONS 3 LAWS OF MOTIONNEWTONS 3 LAWS OF MOTION
The Law of Action-The Law of Action-ReactionReaction
(The 3rd Law of (The 3rd Law of Motion)Motion)
Newton's Third Law of MotionNewton's Third Law of MotionLaw of Action ReactionLaw of Action Reaction
Newton's Third Law of Motion states Newton's Third Law of Motion states that “that “
““For every action, there is an equal For every action, there is an equal and opposite reactionand opposite reaction.”.”
Newton's Third Law of MotionNewton's Third Law of MotionLaw of Action ReactionLaw of Action Reaction
For every action there is an equal and For every action there is an equal and opposite reaction;opposite reaction;
A force acting anywhere always has a A force acting anywhere always has a force equal to that acting in the force equal to that acting in the opposite directionopposite direction
Forces work in pairs opposing one Forces work in pairs opposing one anotheranother
The initial force (action force) is opposed The initial force (action force) is opposed by a second force (reaction force)by a second force (reaction force)
Three Laws Summary
Force SummationForce Summation
Force generation by the body is Force generation by the body is explained in terms of explained in terms of force summationforce summation the sequential acceleration of body the sequential acceleration of body segments, timing of body parts, Range of segments, timing of body parts, Range of Motion (impulse) and Stretching Out.Motion (impulse) and Stretching Out.
The acceleration of body parts can be The acceleration of body parts can be greatly improved through the process of greatly improved through the process of FORCE SUMMATION.FORCE SUMMATION.
Force = mass x accelerationForce = mass x acceleration
Force SummationForce Summation
In many sporting actions such as kicking a In many sporting actions such as kicking a rugby ball, the desired movement is a rugby ball, the desired movement is a combination of a number of body parts combination of a number of body parts and the forces each body part generates. and the forces each body part generates.
These forces are added together through a These forces are added together through a sequence of body movements to generate sequence of body movements to generate a far greater force. a far greater force.
The correct sequence and timing of body The correct sequence and timing of body parts permits the athlete to produce a parts permits the athlete to produce a greater force and therefore attain optimal greater force and therefore attain optimal velocity at release or contact.velocity at release or contact.
Generating greater forceGenerating greater force
The body parts that are large muscle The body parts that are large muscle groups can generate large forces. The groups can generate large forces. The large force causes a large acceleration large force causes a large acceleration in that body part. When that body part in that body part. When that body part reaches peak force then the body part reaches peak force then the body part has reached peak acceleration, after has reached peak acceleration, after which the body part would start which the body part would start decelerating (slow down). decelerating (slow down).
Peak force diagram (see teacher notes)Peak force diagram (see teacher notes)
Force Summation & TimingForce Summation & Timing
The sequence and The sequence and timing timing of the body of the body movements are extremely important in movements are extremely important in order to obtain maximum force generated order to obtain maximum force generated by each successive body part and therefore by each successive body part and therefore maximise the efficiency of the movement.maximise the efficiency of the movement.
Each successive body part should begin to Each successive body part should begin to accelerate when the previous limb has accelerate when the previous limb has reached peak force, and therefore peak reached peak force, and therefore peak accelerationacceleration
Look at these examples;Look at these examples;Girl throw Man throw
The fewer body parts used = less forceThe fewer body parts used = less force
Force summation: ROM and Force summation: ROM and stretching outstretching out
Impulse: Impulse: Applying a Force for a longer Applying a Force for a longer period of timeperiod of time
Muscular force has to be produced when athletes Muscular force has to be produced when athletes want to get moving or they want to accelerate an want to get moving or they want to accelerate an object such as a soccer ball and give it object such as a soccer ball and give it momentum. The force that athletes apply always momentum. The force that athletes apply always takes time. When athletes apply force to an takes time. When athletes apply force to an object over a certain time , we say that the object over a certain time , we say that the athlete has applied an IMPULSE to the object.athlete has applied an IMPULSE to the object.
IMPULSE = FORCE x TIME (force is applied for)IMPULSE = FORCE x TIME (force is applied for) The longer the time the force is applied for, the The longer the time the force is applied for, the
greater the impulse.greater the impulse. Athletes can apply an impulse to their own bodies Athletes can apply an impulse to their own bodies
or to another athlete or to an object.or to another athlete or to an object.
Example of ROMExample of ROM JavelinJavelin
The combination of force and time depends on the needs The combination of force and time depends on the needs of the skill and sport. Some skills, such as punches in of the skill and sport. Some skills, such as punches in boxing, require tremendous forces applied over a very boxing, require tremendous forces applied over a very short time frame. Other skills like throwing a javelin short time frame. Other skills like throwing a javelin require forces applied over a longer timeframe. An require forces applied over a longer timeframe. An expert javelin thrower accelerates the javelin by pulling expert javelin thrower accelerates the javelin by pulling it from way behind his body and releasing it far out in it from way behind his body and releasing it far out in front. Long arms are beneficial as is a backward lean front. Long arms are beneficial as is a backward lean entering the throw position, why? The athlete applies the entering the throw position, why? The athlete applies the force for a long period and therefore more overall force is force for a long period and therefore more overall force is produced.produced.
To do this an athlete will increase the range of motion, To do this an athlete will increase the range of motion, which allows them to apply the force for a longer period which allows them to apply the force for a longer period of time. of time.
Javelin throw
Some working examplesSome working examples
Use these clips to apply the principles Use these clips to apply the principles of force summation we have just of force summation we have just
discusseddiscussedCarter kick
Tennis serveTennis Serve 2Hammer throw
Caber toss
MotionMotion
Forces produce Forces produce three types of motionthree types of motion:: DeformativeDeformative Motion: changing the Motion: changing the
shape of the bodyshape of the body LinearLinear Motion : moving a body from one Motion : moving a body from one
place to another in a straight line. place to another in a straight line. AngularAngular Motion: or rotation , this is Motion: or rotation , this is
where the body rotates or spins about an where the body rotates or spins about an axis (either internal axis or external axis)axis (either internal axis or external axis)
Linear MotionLinear Motion
Where movement Where movement occurs in a straight occurs in a straight line. During line. During translation, all translation, all parts of a body parts of a body move through the move through the same distance in same distance in the same direction the same direction in the same time.in the same time.
Angular MotionAngular Motion
During angular During angular motion or rotation motion or rotation all parts of a body all parts of a body move in a circular move in a circular path around a path around a central axis moving central axis moving through the same through the same angle, in the same angle, in the same direction in the direction in the same time.same time.
Angular MotionAngular MotionThere are two types of There are two types of
axis of rotation:axis of rotation: Internal AxisInternal Axis this is this is
when the axis passes when the axis passes through the body, through the body, usually at a joint, e.g.. usually at a joint, e.g.. the lower leg rotating a the lower leg rotating a bending at knee joint bending at knee joint occurs.occurs.
External AxisExternal Axis this is this is when the axis is outside when the axis is outside the body, e.g.. a giant the body, e.g.. a giant swing in gymnastics.swing in gymnastics.
General MotionGeneral Motion
In physical activity the In physical activity the motion that occurs is quite motion that occurs is quite often a combination of often a combination of linear motion and rotation. linear motion and rotation.
General motion can be General motion can be described as linear described as linear movement of the whole movement of the whole body that is achieved due body that is achieved due to the angular motion of to the angular motion of some of the body parts.some of the body parts.
Projectile MotionProjectile Motion
Projectile:Projectile:
Any body that is Any body that is released into the released into the air becomes air becomes projectile and the projectile and the motion of the motion of the projectile is projectile is governed by a governed by a number of factorsnumber of factors
ForcesForces influencing projectile motion influencing projectile motion
Propelling ForcePropelling Force
GravityGravity
Air ResistanceAir Resistance
Propelling forcePropelling force (force at impact or release) (force at impact or release)
The most important force affects the The most important force affects the projectile in how far and/or how high projectile in how far and/or how high
it travels.it travels.
GravityGravity
Acts equally on all objects, Acts equally on all objects, accelerating the object towards the accelerating the object towards the ground. ground.
Gravity acts on the vertical Gravity acts on the vertical component of the objects motioncomponent of the objects motion
Air resistanceAir resistance
Air particles through which the object Air particles through which the object travels, opposes its forward motion. travels, opposes its forward motion.
Air resistance opposes the horizontal Air resistance opposes the horizontal component of the projectiles motion. component of the projectiles motion.
The lighter the object or the larger its The lighter the object or the larger its surface area, the more it is affected by air surface area, the more it is affected by air resistance. resistance.
Air resistance also increases with speed. Air resistance also increases with speed. e.g. a golf ball drive is more affected than e.g. a golf ball drive is more affected than a chip shot onto the green.a chip shot onto the green.
Quantifying MotionQuantifying Motion Having identified the types of motion a body can Having identified the types of motion a body can
have; biomechanists need to then quantify have; biomechanists need to then quantify (measure) the motion (i.e. describe motion in (measure) the motion (i.e. describe motion in terms of certain quantities) in order to calculate terms of certain quantities) in order to calculate the forces acting. This information can be used to the forces acting. This information can be used to compare and analyse the efficiency of the motion compare and analyse the efficiency of the motion and movements of the athlete.and movements of the athlete.
When we talk about the motion of a body or When we talk about the motion of a body or object we say it moves through a certain object we say it moves through a certain displacement (or distance) in a certain time displacement (or distance) in a certain time interval. (i.e. it has a certain velocity). If that interval. (i.e. it has a certain velocity). If that velocity is changing then the is undergoing velocity is changing then the is undergoing acceleration or decelerationacceleration or deceleration
Factors influencing the Factors influencing the Flight PathFlight Path or or Trajectory Trajectory of a projectileof a projectile
Velocity of releaseVelocity of release
Angle of releaseAngle of release
Height of releaseHeight of release
SpinSpin
Velocity of releaseVelocity of release
The speed at which the projectile The speed at which the projectile leaves the propelling force (bat if leaves the propelling force (bat if hitting, hand if throwing, ground if hitting, hand if throwing, ground if jumping)jumping)
Height of releaseHeight of release
Relative to the height at which the Relative to the height at which the projectile lands, whether it is above projectile lands, whether it is above or below the height at which the or below the height at which the projectile was released.projectile was released.
Angle of releaseAngle of release
The angle that the projectile is The angle that the projectile is released on its flight path.released on its flight path.
SpinSpin
Imparting spin on the projectile (e.g.. Imparting spin on the projectile (e.g.. top spin or back spin in tennis or top spin or back spin in tennis or hooking or slicing as in golf), will hooking or slicing as in golf), will alter the projectiles flight path, alter the projectiles flight path, toward the direction of the spin. toward the direction of the spin.
This is called the “magnus effect”. This is called the “magnus effect”.
Centre of Gravity, Balance and StabilityCentre of Gravity, Balance and Stability
Centre of gravityCentre of gravity in physical activity is explained in physical activity is explained as it relates to balance and stability.as it relates to balance and stability.
BalanceBalance implies co-ordination and control, so that implies co-ordination and control, so that the athlete can neutralise those forces that would the athlete can neutralise those forces that would otherwise disrupt their performance. External otherwise disrupt their performance. External forces such as gravity, friction and contact forces forces such as gravity, friction and contact forces applied by opponents can all unbalance there applied by opponents can all unbalance there position and upset their performance.position and upset their performance.
StabilityStability relates to how much resistance an athlete relates to how much resistance an athlete “puts up” against having their balance disturbed. “puts up” against having their balance disturbed. The more stable an athlete, the more resistance the The more stable an athlete, the more resistance the athlete puts up against disruptive forces.athlete puts up against disruptive forces.
Centre of GravityCentre of Gravity
The point where an The point where an object mass is object mass is
considered to be considered to be concentratedconcentrated
Generally your centre Generally your centre of gravity may be of gravity may be found using the found using the following calculation:following calculation:MALES: 57% of height MALES: 57% of height
(height x 0.57)(height x 0.57)FEMALES: 55% of height FEMALES: 55% of height
(height x 0.55)(height x 0.55)
Principles of EquilibriumPrinciples of Equilibrium
The equilibrium of a body is said to be The equilibrium of a body is said to be STABLE STABLE if, when being slightly displaced the if, when being slightly displaced the body tends to return to its original position. body tends to return to its original position.
The equilibrium is The equilibrium is UNSTABLEUNSTABLE if the body if the body tends to move further from the original tends to move further from the original positionposition..
Equilibrium relies on:Equilibrium relies on:
1. The location of the centre of gravity in 1. The location of the centre of gravity in relation to the base of supportrelation to the base of support
2. The direction of the forces acting2. The direction of the forces acting
Principles of EquilibriumPrinciples of Equilibrium Principle 1 Principle 1 An Athlete increases their stability An Athlete increases their stability
when their Line of Gravity is centralised within their when their Line of Gravity is centralised within their base of support.base of support.
Principle 2Principle 2 An athlete increases their stability An athlete increases their stability when they increase size of their Base of Supportwhen they increase size of their Base of Support..
Principle 3Principle 3 An athlete increases their stability An athlete increases their stability when the lower the height of their Centre of Gravitywhen the lower the height of their Centre of Gravity
Principle 4Principle 4 An athlete increases their stability An athlete increases their stability when they extend their base ,Line of Gravity in the when they extend their base ,Line of Gravity in the direction of an oncoming forcedirection of an oncoming force..
Principles of EquilibriumPrinciples of Equilibrium Principle 5Principle 5 An athlete increase stability by An athlete increase stability by
increasing mass.increasing mass.
Principle 6Principle 6 An increase in Friction can An increase in Friction can improve an athlete’s Stabilityimprove an athlete’s Stability
Principle 7Principle 7 Rotation can improve an Rotation can improve an athlete’s Stabilityathlete’s Stability
Principle 8Principle 8 Shifting the line of gravity Shifting the line of gravity toward oncoming forces can improve stabilitytoward oncoming forces can improve stability
Principles of EquilibriumPrinciples of Equilibrium
Stability of a body depends on :Stability of a body depends on :
The height of the centre of gravityThe height of the centre of gravityThe centrality of the line of gravityThe centrality of the line of gravity
The size of the base of supportThe size of the base of supportThe direction of applied forcesThe direction of applied forces
The mass of the bodyThe mass of the bodyFrictionFriction
Rotation Rotation
MomentumMomentum To understand the concept of momentum, how it To understand the concept of momentum, how it
influences motion and the principle of influences motion and the principle of TRANSFER of MOMENTUM.TRANSFER of MOMENTUM.
MomentumMomentum is the product of a is the product of a MASSMASS that has that has VELOCITYVELOCITY
It is the amount of motion a moving object has, It is the amount of motion a moving object has, is calculated by multiplying the mass of the is calculated by multiplying the mass of the object by its velocityobject by its velocity
MomentumMomentum = MASS x VELOCITY= MASS x VELOCITY
Transfer of Momentum Within a BodyTransfer of Momentum Within a Body
Momentum can also Momentum can also be redistributed be redistributed from one part of the from one part of the body to another body to another part of your body. part of your body.
This transfer of This transfer of momentum is momentum is common in common in jumping, diving and jumping, diving and gymnastics.gymnastics.
Transfer of Momentum Transfer of Momentum from one Body to Another Bodyfrom one Body to Another Body
Momentum can also be transferred from Momentum can also be transferred from one body to another. one body to another.
The momentum that an object possesses The momentum that an object possesses due to its motion is an important due to its motion is an important consideration when there is a collision of consideration when there is a collision of objects. In such collisions objects. In such collisions MOMENTUM MOMENTUM is is TRANSFERREDTRANSFERRED from one body to another from one body to another and vice versus (Newton's 3rd Law of and vice versus (Newton's 3rd Law of Motion).Motion).
Phases of ExecutionPhases of Execution
A phase is a connected group of A phase is a connected group of movements that appear to stand on movements that appear to stand on their own and that the athlete joins their own and that the athlete joins together in the performance of the total together in the performance of the total skillskill
preparation phasepreparation phase = the initial stance and = the initial stance and preparatory movementspreparatory movements
action phase,action phase, = the force producing = the force producing movementsmovements
post action phasepost action phase = the follow through or = the follow through or recoveryrecovery
Phases of Execution Phases of Execution for a Javelin Throwfor a Javelin Throw
Preparation phase Preparation phase
Grip and CarryGrip and Carry Run UpRun Up
Shoulders rotated Shoulders rotated back back
Javelin Drawn BackJavelin Drawn Back Cross-over stepping Cross-over stepping
into final throwing into final throwing stancestance
Phases of Execution Phases of Execution for a Javelin Throwfor a Javelin Throw
Execution /action phase = (force producing Execution /action phase = (force producing movements)movements)
Athlete takes are large step into the throwing stanceAthlete takes are large step into the throwing stance Body Tilted backwardsBody Tilted backwards Centre of Gravity Lowered by flexed rear legCentre of Gravity Lowered by flexed rear leg Rear Leg rotates forward in direction of throwRear Leg rotates forward in direction of throw Hips rotate forward in direction of throwHips rotate forward in direction of throw Torso rotates and pulls shoulder and arm forwardTorso rotates and pulls shoulder and arm forward Lead arm swings back pulling chest and throwing arm Lead arm swings back pulling chest and throwing arm
forwardforward Elbow flexes then extends as it comes forward to Elbow flexes then extends as it comes forward to
releaserelease
Phases of Execution Phases of Execution for a Javelin Throwfor a Javelin Throw
Post action phase =Post action phase = Follow ThroughFollow Through Trailing leg steps forwardTrailing leg steps forward Shoulder and Torso rotate on Follow throughShoulder and Torso rotate on Follow through
Newton's 3 Laws of Motion and Newton's 3 Laws of Motion and Movement SequenceMovement Sequence
Newton's 1st LawNewton's 1st Law The javelin, soccer ball, rugby ball The javelin, soccer ball, rugby ball
will remain at rest until acted on by a will remain at rest until acted on by a force applied by the player.force applied by the player.
The Baseball will remain in straight The Baseball will remain in straight line motion until acted on by a force line motion until acted on by a force Bat and Gravity , which act to change Bat and Gravity , which act to change its motionits motion
Newton's 3 Laws of Motion and Newton's 3 Laws of Motion and Movement SequenceMovement Sequence
Newton's 2nd LawNewton's 2nd Law The acceleration of the javelin, soccer ball, The acceleration of the javelin, soccer ball,
rugby ball or baseball is proportional to rugby ball or baseball is proportional to the force applied by the athlete (and bat)the force applied by the athlete (and bat)
The acceleration of the javelin, soccer ball, The acceleration of the javelin, soccer ball, rugby ball or baseball occur in the rugby ball or baseball occur in the direction that the athlete or bat apply the direction that the athlete or bat apply the forceforce
Newton's 3 Laws of Motion and Newton's 3 Laws of Motion and Movement SequenceMovement Sequence
Newton's 3rd Law of Motion Newton's 3rd Law of Motion The bat applies an action force to the The bat applies an action force to the
ball, but the ball also applies a equal ball, but the ball also applies a equal and opposite reaction force back on and opposite reaction force back on the batthe bat
The players foot applies an action force The players foot applies an action force to the soccer or rugby ball, but the ball to the soccer or rugby ball, but the ball also applies a equal and opposite also applies a equal and opposite reaction force back on the players footreaction force back on the players foot
Force Summation Force Summation and Movement Sequence and Movement Sequence
To generate the most force the athlete will use a To generate the most force the athlete will use a number of body segments to generate forcenumber of body segments to generate force
The force generated in each body segment will The force generated in each body segment will be added together as each body part accelerates be added together as each body part accelerates in a sequential order. in a sequential order.
The following example describes the sequential The following example describes the sequential acceleration of body parts, resulting in successive acceleration of body parts, resulting in successive force summation: force summation:
Throwing/Hitting = Throwing/Hitting = Legs→hips→torso→shoulder→arm or Legs→hips→torso→shoulder→arm or
Kicking = Shoulder→Torso→Hips→ LegKicking = Shoulder→Torso→Hips→ Leg
Force Summation Force Summation and Movement Sequenceand Movement Sequence
In order to generate the greatest force most In order to generate the greatest force most effectively, in any throwing, hitting or kicking effectively, in any throwing, hitting or kicking activity.activity.
The timing of when each successive body part The timing of when each successive body part moves is important. moves is important.
Each body segment should accelerate or begin to Each body segment should accelerate or begin to generate force once the previous segment has generate force once the previous segment has reached its peak force stage. reached its peak force stage.
The following body part (e.g.. forearm) should The following body part (e.g.. forearm) should begin to accelerate once the preceding body part begin to accelerate once the preceding body part (e.g.. upper arm) has reached peak acceleration, (e.g.. upper arm) has reached peak acceleration, which would have accelerated once the previous which would have accelerated once the previous body part (trunk) had reached its peak body part (trunk) had reached its peak acceleration.acceleration.
Force Summation Force Summation and Movement Sequenceand Movement Sequence
If the body parts move to early, before the previous If the body parts move to early, before the previous limb reaches peak force or too late, after the previous limb reaches peak force or too late, after the previous limb has reached peak force. Then less force is limb has reached peak force. Then less force is produced.produced.
By increasing the Range of Motion the athlete can By increasing the Range of Motion the athlete can apply the force for a longer period of time (impulse = apply the force for a longer period of time (impulse = force x time) resulting in a larger force being applied force x time) resulting in a larger force being applied increasing the range of motion allows for increase in increasing the range of motion allows for increase in force.force.
In turn by increasing the range of motion muscles are In turn by increasing the range of motion muscles are Stretched Out and the muscles can then contract Stretched Out and the muscles can then contract more forcefullymore forcefully
Projectile MotionProjectile Motionand Movement Sequenceand Movement Sequence
ForcesForces influencing projectile motion influencing projectile motion
Propelling forcePropelling force The most important force affect the projectile in how The most important force affect the projectile in how
far far and/or how high it travels.and/or how high it travels.
GravityGravityActs equally on all objects, accelerating the object Acts equally on all objects, accelerating the object
towards the ground. Gravity acts on the vertical towards the ground. Gravity acts on the vertical component of the objects motion.component of the objects motion.
Air resistanceAir resistanceAir particles through which the object travels, opposes Air particles through which the object travels, opposes
its forward motion. Air resistance opposes the its forward motion. Air resistance opposes the horizontal component of the projectiles motionhorizontal component of the projectiles motion
Factors influencing the Factors influencing the Flight PathFlight Path or or Trajectory Trajectory of a projectile.of a projectile.
Velocity of releaseVelocity of release The speed at which the projectile leaves the propellingThe speed at which the projectile leaves the propelling
force (bat if hitting, hand if throwing, ground if jumping)force (bat if hitting, hand if throwing, ground if jumping)
Angle of release Angle of release The angle that the projectile is released on its flight path.The angle that the projectile is released on its flight path.
Height of releaseHeight of releaseRelative to the height at which the projectile lands, whetherRelative to the height at which the projectile lands, whetherit is above or below the height at which the projectile wasit is above or below the height at which the projectile was
released.released.
SpinSpinImparting spin on the projectile (e.g.. top spin or back spin in tennis orImparting spin on the projectile (e.g.. top spin or back spin in tennis or
hooking or slicing as in golf), will alter the projectiles flight path, hooking or slicing as in golf), will alter the projectiles flight path, towardtoward
the direction of the spin. This is called the “magnus effect”. the direction of the spin. This is called the “magnus effect”.
Centre of GravityCentre of GravityBalance and EquilibriumBalance and EquilibriumStability in a headstand and handstand Stability in a headstand and handstand
can be improved by:can be improved by:
Increasing the size of the base of support.Increasing the size of the base of support.Maintaining the centrality of the line of gravity insideMaintaining the centrality of the line of gravity inside
the base of support.the base of support.Lowering the height of the centre of gravity.Lowering the height of the centre of gravity.
The direction of applied forces.The direction of applied forces.The mass of the body.The mass of the body.
Friction.Friction.Rotation. Rotation.
Biomechanics SummaryBiomechanics Summary Forces and Motion involved in human movement (sport Forces and Motion involved in human movement (sport
performance)performance)
Force - Force - push, pull that change state of rest or motion of a push, pull that change state of rest or motion of a body, body,
F = m x aF = m x aTypes of forces, effects of forces, impulse (range of motion)Types of forces, effects of forces, impulse (range of motion)
Newton's Three Laws of Motion Newton's Three Laws of Motion
Law of Inertia, Law Acceleration and Action/Reaction.Law of Inertia, Law Acceleration and Action/Reaction.
Force Summation Force Summation sequential acceleration of body segments, timing of body sequential acceleration of body segments, timing of body parts and parts and range of motion and stretching out.range of motion and stretching out.
Biomechanics SummaryBiomechanics Summary Motion Motion
Linear, Angular and General motion, Measuring Motion – Linear, Angular and General motion, Measuring Motion – equations.equations.
Projectile MotionProjectile MotionForces acting = propelling force, gravity, air-resistance, Forces acting = propelling force, gravity, air-resistance,
Influencing factors.= speed, height and angle of release, Influencing factors.= speed, height and angle of release, spin, gravity, air resistance.spin, gravity, air resistance.
Centre of Gravity, Balance, Stability and EquilibriumCentre of Gravity, Balance, Stability and EquilibriumBase of Support, Line of Gravity centralised, Height of C of Base of Support, Line of Gravity centralised, Height of C of G, Extend base & C of G into oncoming forces, increase G, Extend base & C of G into oncoming forces, increase Mass, Increase Friction and rotation.Mass, Increase Friction and rotation.
Biomechanics SummaryBiomechanics Summary Momentum and Transfer of MomentumMomentum and Transfer of Momentum
Amount of motion a moving object has, Amount of motion a moving object has, Force = mass x velocityForce = mass x velocityIn a collision, the momentum of one body can be In a collision, the momentum of one body can be transferred to another.transferred to another.
A complex movement sequence is described A complex movement sequence is described in terms of the phases of execution.in terms of the phases of execution. Javelin, Baseball Hit, Place Kicking a Ball (Soccer or Rugby),Javelin, Baseball Hit, Place Kicking a Ball (Soccer or Rugby),
Phases of execution - preparation phase, Phases of execution - preparation phase, execution/action (force producing) phase, post execution/action (force producing) phase, post action phase.action phase.
Biomechanics SummaryBiomechanics Summary Biomechanical principles are described as Biomechanical principles are described as
they apply to the sequence.they apply to the sequence.Javelin, Baseball Hit, Place Kicking a Ball (Soccer or Rugby).Javelin, Baseball Hit, Place Kicking a Ball (Soccer or Rugby).
Biomechanical principles-, Newton’s laws, Biomechanical principles-, Newton’s laws, momentum, projectile motion, force summation, momentum, projectile motion, force summation, timing of body parts.timing of body parts.
Biomechanical principles are described as Biomechanical principles are described as they apply to the sequence.they apply to the sequence.Gymnastic Balance (Headstand-Handstand)Gymnastic Balance (Headstand-Handstand)
Biomechanical principles – stability and Biomechanical principles – stability and equilibrium, centre of gravity, base of support, Line equilibrium, centre of gravity, base of support, Line of Gravity centralisedof Gravity centralised