Biomechanics Year 11 Physical Education AS 1 2

Biomechanics Year 11 Physical Education AS 1. 2 Credits: 5 Miss Sandri

CALENDAR AUGUST 2013 MONDAY HOSE 16 x Lessons TUESDAY No Lesson WEDNESDAY Hose- Theory 12 13 19 20 15 Projectile Motion/ Leavers 26 16 Practical. Volleyball 21 22 23 27 28 29 30 3 4 5 6 11 12 13 18 19 PHYSIOLOGY STARTS No Lesson Force Summation *Practical* Force Summation 14 Practical- Cross Country OR Frisbee Golf FRIDAY BIOMECANICS Hose- Practical Newton’s Laws Theory No Lesson THURSDAY CALENDAR SEPTEMBER 2013 No Lesson 2 No Lesson Revision 9 16 Study Leave Revision 10 17 EXAM 1. 20 pm

CALENDAR AUGUST 2013 MONDAY BRADLEY 14 x Lessons TUESDAY Bradley- Anatomy WEDNESDAY Bradley- Anatomy 12 Stability/ Force Summation 13 Force Summation. Frisbee Golf 19 Biomechanics Revision & Intro to PHYSIOLOGY 20 Bradley. Cross Country Newton's Laws of Motion THURSDAY FRIDAY No Lesson 14 15 22 27 23 Cross Country. No class No Lesson 26 16 Practical Session. Volleyball No Lesson 21 Force Summation/ Practical 29 30 5 6 11 12 13 18 19 28 CALENDAR SEPTEMBER 2013 No Lesson 2 3 Revision 9 16 4 Study Leave Revision 10 17 EXAM 1. 20 pm

Biomechanics is the study of forces and their effects on the human body during movement. Forces are the basis for all movement.

Body Types Ectomorph: ØTall and slender ØVery little muscle ØBasketball Mesomorph: ØMuscular and athletic ØStrength and endurance ØAthletics Endomorph: ØShort and high proportion of fat ØShort duration ØSwimming, sumo, power lifting

Biomechanics 1. Balance and Stability 2. Force Summation 3. Newton’s Laws 4. Projectile Motion 5. Levers

1. Balance and Stability • Centre of Gravity (Co. G) • Base of Support (Bo. S) • Line of Gravity (Lo. G)

Centre of Gravity • The point at which all parts of an object are equally balanced. • Standing up right our centre of gravity is around our navel. • The centre of gravity changes depending upon what position the body is in. • The centre of gravity can lie outside an object. • Generally, the lower the COG the more stable an object will be.

Base of Support • The area within an object’s point of contact with the ground. • Generally, the larger the area the base of support covers, the more stable an object will be.

Line of Gravity • The vertical line that passes through the centre of gravity to the ground. • The line of gravity is important when determining the stability of an object. • If the line of gravity falls within an object’s base of support the object is relatively stable.

Stability Summary • COG, BOS & LOG • Key points- to maximise stability you should… ▫ ▫ COG Lower the _____ BOS Increase the size of the ____ LOG within the ____ BOS Keep the ____ LOG passes within the ____ COG The _____ • Lets think of some sporting examples…

2. Force Summation • To give an object momentum in activities such as throwing, kicking or striking an object, the amount of momentum given to the object is determined by ‘the sum of all forces generated by each body part’.

Principles of Force Summation… • Use the greatest number of body segments or muscle groups as possible. • In the correct sequence, use large muscle groups first and then the small muscles last, but fast. • Use the correct timing of the body segments or muscle groups.

Force Summation • Stop the video at 7. 25 mins

Research Task • Collect a work sheet and follow the instructions ØWhen finished, come back into the classroom. ØDo now/ for homework: ▫ Using the information you have acquired surrounding force summation, and in table 1, describe your findings and give explanations as to why the throw distance may vary. Use the principles of force summation to explain your answer. DUE: Finished? ? See me!

3. Newton’s 3 Laws of Motion • Sir Isaac Newton Explains the relationship between the forces acting on a body and the motion of a body.

Newton’s 3 Laws of Motion 1 st BOX: Key words, definition. 2 nd BOX: Sports related diagram. 3 rd BOX: Connecting the two.

Law 1: Inertia- an object remains at rest or in motion unless acted upon by an external force.

Law 1: Inertia • Inertia is an objects resistance to change in motion. An objects inertia is proportional to it’s weight (mass). • The heavier the object, the more inertia it has. • Sporting example…

Law 2: Acceleration • Law 2: Acceleration- the acceleration of an object is dependant on the mass, size and direction of the force acting upon it. • force = mass x acceleration [ f = m x a ]

Law 2: Acceleration • When a force is applied to an object, it will move in the direction the force was applied. • Depending on the size/ mass of the object, it will accelerate accordingly. ▫ The smaller the object the faster it will accelerate. ▫ The larger the mass, the slower the acceleration.

Law 3: Action/Reaction • Law 3: Action- reactionwhenever a force is applied there is an equal and opposite reaction.

Law 3: Action/ Reaction • If an athlete exerts a force onto the ground in order to push off, the ground will exert an equal and opposite force on the athlete, pushing them up into the air. • Action force • Reaction force

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Example- Swimming • Think about a swimmer: a) When would Newton’s 3 laws take place? b) How could Newton’s 3 laws of motion help their performance?

Summary: Newton’s 3 Laws of Motion • Sir Isaac Newton Explains the relationship between the forces acting on a body and the motion of a body. Law 1: Inertia- an object remains at rest or in motion unless acted upon by an external force. Law 2: Acceleration- the acceleration of an object is dependant on the mass, size and direction of the force acting upon it. Law 3: Action- reaction- whenever a force is applied there is an equal and opposite reaction.

4. Projectile Motion • Principles of Flight (Projectile Motion) A projectile is an object upon which the only force acting is gravity (for the purposes of this unit we assume air resistance is negligible). This means that even you can be a projectile if you leave the ground!

Projectile Motion • When maximum distance is required there are 3 things that will influence the distance of the projectile. ▫ Height of release. ▫ Speed of release. ▫ Angle of release

Height of Release • For a given speed angle of release, the greater the height of release the greater the distance gained. • Question 1 & 2

Speed of Release • For any given angle of release, speed of release makes a considerable difference to the distance a projectile will travel. • Connection to force summation. • Question 3

Angle of Release When throwing for distance- 45 degrees is the ultimate angle. Question 4

5. Levers • Leavers help apply force as they can move greater loads with a set amount of force. • ▫ ▫ ▫ Most levers have three clearly identified parts: The pivot (or fulcrum) The load (resistance) The effort (force)

Three Types of Levers 1. First Class Lever 2. Second Class Lever e. g. see saw, rower, leg press etc. e. g. a wheel barrow Question 5 Question 6

Third Class Lever • The third class lever is the most applicable to sports biomechanics. • Any instrument such as a bat, club, arm, leg etc could be considered a third class lever. • Question 7 & 8

Levers • Longer levers result in more speed, beneficial for striking and throwing objects. • Shorter levers result in greater strength, beneficial for pushing, pulling, and lifting objects. ▫ Which one has more control? �Try writing with your pen with your hand holding the top of it. • Question 9

Summary • Projectile Motion ▫ Height of release ▫ Angle of release ▫ Speed of release • Levers ▫ First class ▫ Second class ▫ Third class (THE MOST IMPORTANT) �Longer levers= increased speed �Shorter levers= greater strength