“MOVING THROUGH EXERCISE SCIENCE”

1. “MOVING THROUGH EXERCISE SCIENCE” Describe how functional anatomy and biomechanical principles relate to performing physical activity. ACHIEVEMENT STANDARD 2.2 (4 credits) The A Team (Biggs/Hose)

2. BACK TO BASICS • SKELETAL SYSTEM • Bones are living structures with 5 functions: • protect internal organs • support the body • make blood cells • store minerals • provide for muscle attachment

3. IDENTIFYING BONES • Label the bones on the skeleton. Use common names and scientific names e.g. skull and cranium. • Which bones make up the: Elbow joint? Knee joint? Shoulder joint? Hip joint? The femur below has been cut to show the internal structure.

6. MUSCLES • Function – to cause movement • Controlled by nerves (some voluntary, some involuntary) • Contract (shorten) – which brings bones closer together, therefore for movements to occur in both directions the muscles must work together in pairs e.g. bicep & triceps, hamstrings & quadriceps.

8. HOW MUSCLES MOVE • Muscles are attached to two different bones by tendons. When the muscle contracts only one bone moves. • The place where the muscle is attached to the stationary bone is called the ORIGIN. The place where the muscle is attached to the moving bone is called the INSERTION. Origin Insertion

9. AGONIST/ANTAGONIST • Muscles can only pull. To make a joint move in two directions, you need two muscles that can pull in opposite directions. • Antagonistic muscles are pairs of muscles that work against each other. One muscle contracts (agonist, or prime mover) while the other one relaxes (antagonist) and vice versa. • The origin is where the muscle joins the fixed bone. The insertion is where it joins the moving bone. On contraction, the insertion moves towards the origin.

10. MUSCLES FOR ENDURANCE AND POWER • Muscles are made up of fibres. All individual voluntary muscle fibres are either fast twitch or slow twitch and these are good for different things. Fast Twitch for Power, Slow Twitch for Endurance • Fast twitch fibres contract very quickly and very powerfully, but they get tired quickly as they run out of oxygen in under 10 seconds. They are useful for sprinting and weightlifting or other activities requiring anaerobic exercise. • Slow twitch fibres contract more slowly and with less force, but they don't get tired as quickly and can replace some of the oxygen that is used. They are useful for jogging and endurance activities. • Everyone has a similar number of muscle fibres, but the proportion of fast twitch and slow twitch fibres that people have differ. You cannot change the amount of slow or fast twitch muscle fibres that you have. • Does this mean sprinters are born with a natural talent or trained?

11. QUESTIONS • What is the difference between the origin and the insertion? • Name 3 different activities that would require a high percentage of fast twitch fibres. • Name 2 different antagonistic pairs of muscles and the movements they make.

12. HOW MUCH DO YOU KNOW ABOUT MUSCLES AND THEIR MOVEMENTS

17. JOINTS • Movement of the skeleton is helped by joints. These are particularly helpful for sporting actions and activities. These can be separated into FOUR categories of joints. • Ball and Socket Joint • Hinge Joint • Pivot Joint • Gliding Joint

18. BALL AND SOCKET • Two examples of this joint in the human body are the hip and shoulder joints. • The rounded head of one bone fits into a cup-shaped socket of another. This joint allows the greatest range of movement.

19. BALL AND SOCKET

20. HINGE JOINT Two examples of this type of joint include those found at the knee and elbow. 1) If you move your hand towards and away from you. 2) If you move your leg as if you were about to kick a ball. You will find that the movement of the joint can only occur in one way (direction) just like the hinge of a door!!

21. GLIDING JOINT • In this type of joint, two surfaces which are flat rub against each other. These small bones can move over one another to increase flexibility of the hands for example. They are stopped from moving too far by strong ligaments.

22. PIVOT JOINT • This joint is made when one bone twists against another. • These are found in the spine. They also allow the head to turn, raise and lower. • Extremely important for keeping balance and awareness.

23. QUESTIONS • On the skeleton identify the joint types labelled at 2, 3 and 5. (e.g. ball and socket, gliding, hinge, pivot) • In the diagram to the right, which joint types do figures 1, 4 and 5 represent? (e.g. ball and socket, hinge etc.)

24. BIOMECHANICS • Biomechanics is the study of forces and their effects on the human body during movement. • We shall look at the following biomechanical principals: • Inertia • Action/reaction • Projectile Motion • Force Summation • Levers

25. Newton’s Laws Of Motion • Sir Isaac Newton studied the effect of the forces on movement and from his observations developed three laws of motion to explain the relationship between motion and applied force.

26. 1st Law – the law of Inertia • Every body will remain in a state of constant motion or rest unless acted on by a force. • For a body to get moving the force has to be greater than the inertia acting upon it (inertia = a bodies tendency to remain at rest. The greater the mass of the body = greater the inertia).

27. 2nd Law – the law of Acceleration • The acceleration of an object is directly proportional to the force causing it, is in the same direction as the applied force, and is inversely proportional to the mass of the object.

28. 3rd Law – the law of Action/Reaction • For every action there is an equal and opposite reaction.

29. FORCE SUMMATION

30. FORCE SUMMATION • To gain maximum momentum, the force needs to be generated by: • Using as many segments of the body as possible. • In the correct sequence, using large muscles first and then the smallest muscles last but fastest. • With the correct timing. • Through the greatest range of motion.

31. EXAMPLE

36. PROJECTILE MOTION

37. PRINCIPLES THAT AFFECT PROJECTILES • Regardless of the type of object that is being released, or by what means it is being projected, they are all governed by the same principles.

38. Gravity acts on a body to give it mass. The greater the weight of an object the greater the influence of gravity upon it. • What is the effect of gravity on a projectile?

40. SPEED OF RELEASE

41. ANGLE OF RELEASE

42. HEIGHT OF RELEASE • The inter-relationship between height of release and angle of release is important to consider. • The inter-relationship between height of release and angle of release is important to consider.

43. The reason behind this can be summarized as follows As the height of release increases, the angle of release decreases. As the height of release decreases, the angle of release increases.

44. PROJECTILE JET PLANES • Make a paper jet plane. • When throwing jet plane, manipulate projectile variables to achieve maximum distance. • E.g. throw from different heights – standing, sitting on your knees, standing on a chair. • Use fast and slow hand speeds. • Try different angles of release.

46. SOOOO…….. • This leads us to the following two principles with respect to projectiles and spin. • Range is decreased with topspin. • Range is increased with backspin. • WHY?

47. PRACTICAL EXAMPLE • Question? • How is this biomechanical principle applied to the overhead serve in volleyball. Where can I see this being applied?

48. ANSWER • Firstly the speed or the force that the ball is struck/released at is important. The speed at which the ball is struck will determine how far the ball will travel. The striking force must be sufficient enough to allow the ball to cross the net but not enough to mean the ball goes out of play.

49. The height of release also influences the horizontal distance covered, too high and the ball may go to far, too low and the ball may strike the net. The angle is also important in conjunction with this. The angle and height of release must be judged correctly in order that the serve is successful. Spin can also be applied in order to make the ball dip after the net-making it harder for teams to return.

50. A lever is used when you want to apply more force. • Most levers have three clearly identified parts: • THE FULCRUM The pivot point around which the movement happens. In the body this is usually the joint. 2.THE LOAD The weight that needs to be moved. 3.THE FORCE The place where the force is applied. In the body this is the effort produced by the muscles contracting .