This document discusses biomechanics and its application to sports. It covers Newton's laws of motion and how they relate to concepts like inertia, acceleration, and reaction forces. It also discusses levers, equilibrium, center of gravity, and forces like centripetal and centrifugal forces. Biomechanics helps improve sports performance and technique, prevent injuries, and optimize training and equipment by analyzing human movement and applying principles of mechanics.

1. Biomechanics and Sports
1. Biomechanics and Sports
1.1 Meaning and Importance of Biomechanics in Physical Education and Sports
1.2 Newton’s Law of Motion and its Application in Sports
1.3 Levers and its types and its Application in Sports
1.4 Equilibrium- Dynamic and Static and Centre of Gravity and its Application in Sports
1.5 Force- Centrifugal and Centripetal and its Applications in Sports
2. Meaning of Biomechanics
 The study and analysis of human movement patterns in sports is called Biomechanics
 The study of the structure and function of biological systems such as humans, animals,
plants, organs, and cells by means of the methods of mechanics
 The application of mechanical laws to living structures
3. Importance of Biomechanics in Physical Education and Sports
Helps in Improving Technique
a) Correct or rectify the errors of a sports person to improve the execution of a skill
b) Discover a new and more effective technique for performing a sport skill
c) Fosbury Flop and straddle technique
d) Qualitative biomechanical analysis for correction
e) Quantitative biomechanical analysis for discovering new techniques
Helps in Improving Equipment
a) Helps in improving the designs of the equipment
b) Shoes & sports clothes design improved
c) Better equipment improves performance and reduces the risk of injury
d) Better Rackets in racket games
e) Better Helmets to reduce risk of injury in ice hockey, football and many other games
f) Aerodynamic clothing in skiing, speed skating, cycling, swimming etc.
Helps in improving the performance
a) By utilizing biomechanics to improve techniques
b) By utilizing biomechanics to improve equipment
c) By utilizing biomechanics to reducing the risk of sports related injuries
Helps in preventing injuries
a) Identifies the causes of injury
b) Helps in process of rehabilitation
c) By identifying cause and rehabilitation exercises changes are made in techniques,
equipment to reduce the risk of sports related injuries

2. Helps in the improvement of the training
a) Mechanical analysis of the technical deficiencies of a sports person helps identify the
type of training required
b) The weak areas may be strength, endurance, speed of movement or body actions
c) Customized training can be imparted to the sports person
Helps in improving teaching and learning process
a) Biomechanics helps in moving the body with precision
b) Understanding of biomechanics helps the teacher to take right decisions
c) Understanding of biomechanics helps sports person to learn his weaker areas and
provides motivation to correct the actions/ postures to enhance performance and prevent
injuries
4. Newton’s Laws of motion and their application in Sports
 When exploring the area of biomechanics and human movement, it is useful to look at
motion through the observations made by Sir Isaac Newton.
 Newton was a famous seventeenth- century scientist who developed the three laws that
govern all motion.
5. Newton’s 1st Law – The law of Inertia
 ‘A body continues in its state of rest or uniform motion unless acted upon by an
unbalanced force.’
 In other words, a body will remain at rest or in motion unless acted upon by a force. In
order to get a body moving, a force must overcome the body’s tendency to remain at rest
or inertia. The amount of inertia a body has depends on its mass.
Newton’s 1st Law – The law of inertia
 This soccer ball will remain at rest, until a force acts on it
6. Newton’s 2nd Law of Acceleration
 The acceleration of an object is directly proportional to the force causing it, is in the
same direction as the force, and is inversely proportional to the mass of the object.
 When a force is applied to an object it will move in the direction the force was applied,
and, depending on the size of the force and the size of the object, the object will
accelerate accordingly.
 Smaller object will move faster than a larger one
 A greater force will move an object faster than a smaller force.
Newton’s 2nd Law – mass, force & acceleration f = ma
Newton’s 2nd Law of Reaction
 ‘Whenever a force is applied there is an equal and opposite 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.

3.  The first force of the athlete pushing into the ground is called an action force. The
second force is called the reaction force (when the second body applies an opposing force
back).
7. Newton’s 3rd Law – action & reaction
Application of force summation – free-throw shot technique
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’ (i.e. Force summation).
 To gain maximum momentum, the force needs to be generated by:
1. Using as many segments of the body as possible.
2. In the correct sequence, using large muscles first and then the smallest muscles last
but fastest.
3. With correct timing.
4. Through the greatest range of motion.
Application of force summation – free-throw shot technique
 In order to maximize power and efficiency of the shot, the whole body is used.
 Your body does not move all at once.
 The shot begins with the movement of the legs, pushing into the ground.
 The force is then returned back up the legs, up to the shoulders, down the forearms
right to the release of the ball at the fingertips.
8. Levers and its Types and its application in Sports
Lever is a simple Machine
 Machines function in four ways
 balance multiple forces
 enhance force in an attempt to reduce total force needed to overcome a resistance
 enhance range of motion & speed of movement so that resistance may be moved
further or faster than applied force
 alter resulting direction of the applied force
9. 24. © 2007 McGraw-Hill Higher Education. All rights reserved 3- 25 Levers  Levers
rotate about an axis as a result of force (effort, E) being applied to cause its movement
against a resistance or weight  In the body bones represent the bars joints are the axes
muscles contract to apply force
10. 25. © 2007 McGraw-Hill Higher Education. All rights reserved 3- 26 Levers 
Resistance can vary from maximal to minimal ◦ May be only the bones or weight of body
segment  All lever systems have each of these three components in one of three possible
arrangements

4. 11. 26. © 2007 McGraw-Hill Higher Education. All rights reserved 3- 27 Levers  Three
points determine type of lever & for which kind of motion it is best suited ◦ Axis (A)-
fulcrum - the point of rotation ◦ Point (F) of force application (usually muscle insertion) ◦
Point (R) of resistance application (center of gravity of lever) or (location of an external
resistance)
12. 27. Types of Levers  1st class lever – axis (A) between force (F) & resistance (R)  2nd
class lever – resistance (R) between axis (A) & force (F)  3rd class lever – force (F)
between axis (A) & resistance (R)
13. 28. © 2007 McGraw-Hill Higher Education. All rights reserved 3- 29 • AFR Class 3 |
Resistance Arm | • ARF Class 2 | Force Arm | Types of Levers • FAR Class 1 A F R |
Force Arm || Resistance Arm | A R | Resistance Arm | F A R | Force Arm | F
14. 29. Class 1 Lever : FAR Fulcrum Effort Load
15. 30. Class 2 Lever : ARF Load Fulcrum Effort
16. 31. Class 3 Lever : AFR Load Fulcrum Effort
17. 32. © 2007 McGraw-Hill Higher Education. All rights reserved 3- 33 Types of machines
found in the body  Musculoskeletel system arrangement provides for 3 types of
machines in producing movement ◦ Levers (most common) ◦ Wheel-axles ◦ Pulleys
18. 33. © 2007 McGraw-Hill Higher Education. All rights reserved 3- 34 Types of Levers in
Human Body  Humans moves through a system of levers  Levers cannot be changed,
but they can be utilized more efficiently ◦ lever - a rigid bar that turns about an axis of
rotation or a fulcrum ◦ axis - point of rotation about which lever moves  In the human
body, levers are made up of the joints (fulcrum) and the bones that connect them to the
objects being moved.
19. 34. Types of Levers in Human Body
20. 35. Application of Levers in Sport  Human leverage for sport skills requires several
levers ◦ throwing a ball involves levers at shoulder, elbow, & wrist joints  The longer
the lever, the more effective it is in imparting velocity ◦ A tennis player can hit a tennis
ball harder with a straight-arm drive than with a bent elbow because the lever (including
the racket) is longer & moves at a faster speed
21. 36. 9.4 Equilibrium- Dynamic and Static and Centre of Gravity and its Applications in
Sports
22. 37. 3- 38 9.4 Equilibrium  Equilibrium - state of zero acceleration where there is no
change in the speed or direction of the body ◦ Static ◦ Dynamic  Balance - ability to
control equilibrium, either static or dynamic
23. 38. 9.4 Types of Equilibrium  Static equilibrium - Body is at rest or completely
motionless  Dynamic equilibrium - all applied & inertial forces acting on the moving
body are in balance, resulting in movement with unchanging speed or direction  To
control equilibrium & achieve balance, stability needs to be maximized
24. 39. 9.4 Principles of Stability  Stability is the resistance to a ◦ change in the body's
acceleration ◦ disturbance of the body's equilibrium  Stability is enhanced by
determining body's center of gravity & appropriately changing it  Center of gravity -
point at which all of body's mass & weight are equally balanced or equally distributed in
all directions  Balance - important in resting & moving bodies
25. 40. 3- 41 9.4 Principles of Stability  General factors applicable to enhancing
equilibrium, maximizing stability, & ultimately achieving balance: 1. A person has

5. balance when the center of gravity falls within the base of support 2. A person has
balance in the direct proportion to the size of the base. The larger the base of support, the
more balance
26. 41. 9.4 Principles of Stability 3. A person has balance depending on the weight
(mass).The greater the weight, the more balance 4. A person has balance, depending on
the height of the center of gravity The lower the center of gravity, the more balance 5. A
person has balance, depending on where the center of gravity is in relation to the base of
support Balance is less if the center of gravity is near the edge of the base
27. 42. 9.4 Centre of gravity  Centre of gravity can be defined as “the single point at which
all parts of an object are equally balanced”.  A persons centre of gravity can change
depending on their body position as the centre of gravity is the exact point where all parts
of an object are equally balanced.
28. 43. 9.4 Centre of gravity = Centre of gravity For a ‘normal’ human being standing
upright, their centre of gravity lies around the area of their navel
29. 44. 9.4 Centre of gravity Centre of gravity of a boy whose hands are stretched in the air =
Centre of gravity
30. 45. The centre of gravity can also lie outside an object, especially if the object is bent
over or leaning in a certain direction 9.4Centre of gravity = Centre of gravity
31. 46. Line of gravity  Line of gravity is the vertical line that passes through the centre of
gravity to the ground.  If the line of gravity falls within the object’s base of support (i.e.
its contact with the ground), the object is relatively stable.  If the line of gravity falls
outside the object’s base of support (i.e. its contact with the ground), the object is
relatively unstable.
32. 47. Line of gravity Centre of gravity STABLE Centre of gravity UNSTABLE Line of
gravity Line of gravity
33. 48. Base of support – The object on the left is more stable because of its relatively larger
BOS  BOS is the area within an objects point of contact with the ground. The larger the
area the base of support covers, the more stable an object will be. Wide BOS Narrow
BOS BOS BOS
34. 49. 9.5 Force- Centripetal and Centrifugal and its Applications in Sports
35. 50. 9.5 Force  Forces either push or pull on an object in an attempt to affect motion or
shape  Without forces acting on an object there would be no motion  Force - product
of mass times acceleration  Mass - amount of matter in a body
36. 51. 3- 53 9.5 Force Force = mass x acceleration F = M x A  Momentum (quantity of
motion) - equal to mass times velocity  The greater the momentum, the greater the
resistance to change in the inertia or state of motion
37. 52. 3- 54 9.5 Factors related to Movement Activities 1. The production of Force 2. The
application of Force 3. The absorption of Force
38. 53. 3- 55 9.5 Factors related to Movement Activities 1. The production of Force 
External forces are produced from outside the body & originate from gravity, inertia, or
direct contact  Only muscles can actively generate internal force, but tension in tendons,
connective tissues, ligaments, and joints capsules may generate passive internal forces
39. 54. 3- 56 9.5 Factors related to Movement Activities 1. The production of Force  The
appropriate sequence to get maximum force is necessary

6. 40. 55. 3- 57 9.5 Factors related to Movement Activities 2. The application of Force  The
force on an object must be applied in the direction in which it has to travel  All activities
require a summation of forces from the beginning of movement in the lower segment of
the body to the twisting of the trunk and movement at the shoulder, elbow, and wrist
joints
41. 56. 3- 58 9.5 Factors related to Movement Activities 3. The absorption of Force 
Significant mechanical loads are generated & absorbed by the tissues of the body 
Tension in tendons, connective tissues, ligaments, and joints capsules may generate
passive internal forces
42. 57. 3- 59 9.5 Factors related to Movement Activities 3. The absorption of Force 
Internal forces can ◦fracture bones ◦dislocate joints ◦disrupt muscles & connective tissues
 To prevent injury or damage from tissue deformation the body must be used to absorb
energy from both internal & external forces
43. 58. 3- 60 9.5 Centripetal & Centrifugal Force When an object is rotating around a fixed
axis in a circular path, two opposing forces act on the object- 1. Centripetal Force 2.
Centrifugal Force
44. 59. 3- 61 9.5 Centripetal Force The force which keeps the body moving with a uniform
speed along a circular path and is directed along the radius towards the centre 1. Causes
object to move towards the centre
45. 60. 3- 62 9.5 Centrifugal Force When centripetal force acts upon a body, another force
equal to the centripetal force but opposite to the direction also acts upon it. This force is
called Centrifugal force. 1. Causes object to move away from the centre
46. 61. 9.5 Force – its Application in Sports  In the performance of various sport skills such
as throwing, many applications of the laws of leverage, motion, and balance may be
found  In throwing, the angular motion of the levers (bones) of the body (trunk,
shoulder, elbow, and wrist) is used to give linear motion to the ball when it is released
47. 62. Application of centripetal and Centrifugal force in Sports
48. 63. Application of centripetal and Centrifugal force in Sports