Improvement
Performance
Physical Education
Scholarship
Presentation 2011
Presenter: Chris Bright
Whangaparaoa College
• Programmes for performance
improvement drawing upon knowledge
underpinning achievement standards
90741, 90742.
Factors Effecting a Programme of Performance
Improvement
Biophysical
Factors
Social – Cultural
Factors
Biophysical
“The way in which scientific knowledge can be
utilized in an attempt to enhance involvement
and performance in physical activity.”
Biophysical Factors
Sports Nutrition – hydration, energy
requirements, tissue growth and repair
Sports Psychology – goal setting, mental
rehearsal, levels of arousal, motivation,
feedback
Sports Medicine
Exercise Physiology- energy systems, acute and
chronic training effects
Coaching
Biophysical Factors cont..
Biomechanical Analysis- Internal Forces:
Functional Anatomy- muscle architecture
Types of Movements
• Flexion / Extension
• Adduction / Abduction
• Rotation (internal /
External)
• Plantar-flexion / Dorsiflexion
• Supination / Pronation
How do Muscles work?
Muscles work in pairs.
One muscle has to
contract and the other
muscle has to relax to
allow the movement of
the joint. For example
The biceps contract and
the triceps relax to allow
the elbow joint to move
Muscle Fibre Types
• Fast twitch (type 1&2)
• Slow Twitch
Agonists
• The Agonist is the prime
mover (the main muscle
responsible for the
movement).
• In this picture the
biceps is the agonist
muscle. The agonist is
usually the muscle
working against gravity.
Antagonist
• The Antagonist is the
opposing (relaxing,
lengthening) muscle in
the joint action.
• In the picture the
triceps is the antagonist
muscle. The antagonist
muscle is usually
working with gravity.
Biomechanical Analysis –External Forces:
technique and:
• Newton’s laws,
• Levers,
• Force Summation,
• Projectile motion,
• Stability
Biomechanical Overview
Newton’s Laws
Stability
Force Summation
Levers
Projectile
Motion
1st Law:
Inerita
An object will stay in its
current state of motion until
a internal or external force is
applied to it
Newton’s Laws
The acceleration of an object
2nd Law:
Acceleratio is directly proportional to the
force causing it, and is
n
inversely proportional to the
mass of the object
3rd Law:
Action/
Reaction
For every action there is an
equal and opposite reaction
Stability
• Stability is a high degree of equilibrium and is
defined as a body’s resistance to movement
either linear or angular from a balanced
position.
• Balance: Increasing the Base of Support and
lowering the centre of gravity allows a player
to apply force over a larger distance and
period of time without losing balance.
Stability and mobility are inversely related
Factors Effecting Stability
•
•
•
•
The mass of the body
The height of the centre of gravity
The area of the supporting base
The position of the line of the centre of mass
Stability
• Base of Support
• Centre of Gravity
• Line of Gravity
Force Summation
• Allows maximum forces to be produced by the muscles
and then transferred into physical activity movements.
• This is achieved by adding the forces of each body
segment together, producing a larger force than is
possible if only one body part was used.
• The more the body parts involved in completing a
movement, the greater the force that can potentially
be generated and then be transferred to a striking
implement such as a racket or bat.
• Each body part used in a movement tends to
accelerate and then decelerate after having been used.
Summation of Forces
•
•
•
•
Summation of Forces are effected by 3 Factors
1: Range of Motion
2. Segmented Interaction
3. Co-ordination Continuum
Range of Motion
• The degree of movement can determine the
amount of speed used or absorbed in a
movement. Range of motion can be
influenced by the preparation and follow
through sequence of a movement
Range of Motion cont..
• Range of motion is
effected by the person’s
flexibility.
• How could this effect
someone’s ability to
produce force.
• How can you increase a
person’s range of
motion.
Co-ordination Continuum
• To maximise force production, each body
segment should be used when the one before
reaches its peak force to allow maximum
transfer of force between body parts
Segmental Interaction
• Forces can be transferred between joints and
body segments. Large muscles often generate
force and transfer these sequentially (through
progressively smaller and more distal muscles
or the extremities) to complete the movement
Levers
Levers are simple
machines which help
apply force and speed
more easily. Levers help
to move greater loads
with a set amount of
force. Levers help move
loads at greater speeds.
Levers involve 5 Parts
•
•
•
•
•
Force
Resistance
Resistance arm
Force arm
Fulcrum
Parts of a Lever
• Force: a force is applied at right angles to the
force arm
• Force arm: the distance between the fulcrum
and the applied force
• Resistance (load): the weight that needs to be
moved
• Fulcrum: the pivot point
• Resistance arm: the distance between the
fulcrum and the resistance
1st Class Levers
• In this type of lever the
fulcrum sits between the
load and the force applied.
• Can be used to either
increase the force or speed
• Speed = force arm shorter
than resistance arm
• Strength = force arm longer
than resistance arm
nd
2
Class Levers
• In this type of lever the
resistance (load) sits in
between the fulcrum
and the force applied
• A 2nd class lever allows
more force to be
produced because the
force arm is longer than
the resistance arm
3rd Class Levers
• This type of lever the force sits in between the fulcrum and
the resistance (load)
• 3rd class levers are the most common in the human body
• This type of lever allows more speed to be produced because
the resistance arm is longer than the force arm
Maximising lever length to improve
performance
• Shortening the lever arm (by bending the joint)
allows the lever arm to generate force and to be
rotated with more speed.
• Once this has been achieved the lever arm can be
lengthened (by straightening the joint) to maximise
speed at the end of the lever.
• The internal levers can be lengthened by using
implements such as golf clubs and rackets
Projectile Motion
A projectile is any object which is travelling through
the air. For example a gridiron ball etc
Projectile Motion
•
•
•
•
Projectile Motion is dependent on many
factors
Angle of Release
Height of Release
Speed of Release
Spin
Height of Release
The higher the release point the further an
object will travel. If the landing height is
higher than the release height, the horizontal
range is decreased.
As height increases, optimum
angle is less (for any speed
Angle of Release
The optimum angle of release you need to throw a projectile is
450. If the angle is too high, the horizontal component is
reduced, thus reducing the horizontal distance. If the angle of
release is too low, the vertical component is reduced, thus
reducing the time of flight which, in turn, reduces horizontal
distance.
Horizontal (distance) – Long jump
Vertical (h)
Vertical (h) - Badminton
Horizontal (d)
Speed of Release
The greater the speed of release the great the
distance covered/ travelled by the projectile
Projectile Motion & Spin
As a projectile spins, one side spins in the
same direction as that of the on coming air
flow (creating a low-pressure zone) and the
other side spins in the opposite direction
(creating a high-pressure zone). A projectile
has a tendency to move from a high to a low
pressure zone this is called the Magnus effect
Projectile & Spin cont…
Air moves from high
to low pressure forcing the
ball downward
The ball rises through
the air
Low pressure Zone
Air flow
Ball spins in opposite direction
to air flow
The ball – dips downward towards
the ground
High pressure zone
Skill Acquisition
• Dynamical Systems Theory:
• “Dynamical Systems Theory is a theory that is
concerned with the stability, the variability,
and the adaptability of co-ordinated
movement patterns.”
Dynamical Systems Theory
• Davids, Glazier, Araujo, & Barlett (2003)
discuss the movement systems as a dynamical
system. They state that variability in
movement systems help individuals adapt to
their unique constraints (that is personal or
organism, task, and environmental) impinging
in them across different timescales.
Dynamical Systems Theory
• This theory underpins how the human body as
a ‘movement system’ is able to control
movement and develop specific movement
patterns, known as motor skills to interact
with the world around them in a variety of
ways.
Dynamical Systems Theory
Motor Learning
Constraints
Self Organisation
Degrees of Freedom
Problem
Organism
Environment
Task at
Hand
Co-ordinating the
Degrees of Freedom of
the Body
Converting the body into
a controllable system assembly of a functional
pattern
Self Organisation
• Self Organisation is also the tendency for coordinated solutions to be found under the
interaction of a variety of constraints. this can
be practice and if given time the organism will
find he best co-ordination for the task.
Different Athletes (even at the elite level) will
have differences in technique because of
differences in organism level constraints
Constraints
• Boundaries which limit the co-ordination
states in a dynamical movement system
during the search for a movement solution.
The three constraints mentioned below
interact within each other to set the
boundaries of movement
• Organism
• Environment
• Task at Hand
Organism
• This is the Individual performer and the
constraints that they bring to the movements
• Organism Constraints
• Physical Characteristics ( to do with the body,
biomechanics, physiological etc),Congitive
factors, Psychological factors, Emotional
factors Neurology
• Genictics factors
Environment
• Constraints that are external to the organism
• Environmental Constraints
• Culture (eg some sports are male dominated
due to requirements of strength)
• The Physical Environment: (gravity, air
resistance, type of light, temperature etc)
• Social Co-ordination (how you interact with
your team mates
Task at Hand
• Goals of the activity
• The tasks at hand influence the way we
produce co-ordinated behaviour. Sometimes
practice in one sport influences the way we
move in another sport.
• Some sporting tasks have rules
specificing/constrainting the response pattern
eg swimming strokes etc
Motor Learning
• Degrees of Freedom Problem
• Co-ordinating the Degrees of Freedom of the
body
• Converting the body into a controllable system
• Assembly of a functional pattern
Motor Learning
• Degrees of Freedom Problem
• Degrees of Freedom is any value that is free to
vary. eg muscles in the body can create
individual movements. The problem for the
organism is how to control / co-ordinate the
degrees of freedom
• Co-ordinating the Degrees of Freedom of the
Body
• Practice: re-organising movement system degrees
of freedom to produce functional informationmovement couplings (basically allows the body to
learn a skill by bringing together the degrees of
freedom of movements in a certain pattern). This
strategy of reducing or increasing involvement of
movement system degrees of freedom is a
contraints led approach
• Converting the body into a controllable system assembly of a functional pattern
• Degrees of Freedom (DF) can be frozen (used in
isolation) or Unfrozen (used in sequence with
other movement patterns). Practice allows
organisms to unfreeze DF to improvement
performance. When learning a new skill DF are
frozen (stiff, jerky movements) With practice DF
are unfrozen (fluid, smooth movement). This
allows better summation of forces (connected
kinetic chain)
Instruction and Feedback
• Augmented information that directs the
learners search for solutions that satisfy
constraints imposed on them
• Need to ensure not to give to much feedback
to learners as to confuse them. But to let
them explore the constraints of the
movement system (their body) can guide
them to find the best movement pattern for
them
Constraints Led Approach to Skill
Acquisition
• Practice - direct learners to search to satisfy
constraints
• Manipulate the constraints in practice equipment, modify rules, practice design
• Simply task
• Instructional constraints with an external
focus allows self organisation
Questions?
• Questions???
• How does types of practice fit into the
Dynamical Systems Theory
• What role does Biomechanics fit into this
Theory
• How does Social / Cultural Factors fit into this
theory?
• Does the phrase one size fits all fit into this
theory?