Improvement Performance

Physical Education Scholarship Presentation

2011

Presenter: Chris BrightWhangaparaoa 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 FactorsSports Nutrition – hydration, energy

requirements, tissue growth and repairSports Psychology – goal setting, mental

rehearsal, levels of arousal, motivation, feedback

Sports MedicineExercise 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 / Dorsi-

flexion• Supination / Pronation

How do Muscles work?

Muscles work in pairs. One muscle has tocontract and the othermuscle has to relax to allow the movement of the joint. For exampleThe biceps contract andthe 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

Newton’s Laws

Stability Force Summation

Projectile Motion Levers

Biomechanical Overview

Newton’s Laws1st Law: Inerita

An object will stay in its current state of motion until a internal or external force is applied to it

2nd Law: Acceleration

The acceleration of an object is directly proportional to the force causing it, and is 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

2nd 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 (d)

Vertical (h)

Horizontal (distance) – Long jump

Vertical (h) - Badminton

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…

Low pressure Zone

Air flow

The ball rises through the air

High pressure zone

Air moves from high to low pressure forcing the

ball downward

Ball spins in opposite direction to air flow

The ball – dips downward towards the ground

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

Constraints Self Organisation

Organism Environment Task at Hand

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

Self Organisation

• Self Organisation is also the tendency for co-ordinated 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 information-movement 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?