BIOMECHANICS IN SPORTS

1.  Home About Sports Bio Mechanics
Introduction
During the early 1970s. The international community adopted the terms Bio- Mechanics to describe the
application of mechanical principles in the study of living organisms. As it was realized after 1950 that the
mechanical principles involving on the human body is entirely different from other things.
Internal forces and take place under the effect of external forces eg. When we walk.
A background of mechanics can help coaches to know their sport more, make them more confident about
their practice and extent their knowledge beyond the technique to know the scientific reason. They will be
better prepared to answer-
Why we do it this way? Why should not I do this way? – Student deserves better answer than because as
a coach- I said.
 What technique is the best?
 Should I teach this technique to my students or it is suitable only for top class Athletes ?
 What is wrong with this individual’s performance and how can I correct it.
 What exercise should I prescribe to improve this individual’s physical condition?
Meaning of Bio-mechanic
When the study of mechanics is limited to living structure, especially the human body, it is called Bio-
mechanics.
The Bio-mechanics has derived from two words-Biomechanics.
Bio means, some thing pertaining to living being or life.
Mechanics -means, the discipline which studies the movement of object/motion of objects with the help of
mechanical principles.
Mechanics is a branch of physics which study the object/ from mechanical point of view. So, the
knowledge of Bio-mechanics used to study and analysis the movement of living things. Any object is
moving, it depends upon the resultant of various forces acting on the body.
Definition of Bio-mechanics
"The area of study where the knowledge and methods of mechanics are applied to the structure and
function of the living human system"
"Bio-mechanics is the science concerned with the internal and external forces acting on a human body
and the effects produced by these forces".
Definition
KINESIOLOGY
"It is a field of study based upon the anatomical and mechanical analysis of human motion".
- HAY & REID
MECHANICS
"It is that branch of physics concern with the effect that forces have on bodies and the motion produced by
these forces".
- WELL
BIO-MECHANICS
"Science concerned with the internal and external forces acting on a human body and the effects
produced by these forces".

2. - JAMES G. HAY
The term biomechanics refers to -
"Mechanical bases of biological especially to the Muscular activity and the principles and the relations
involved there in".
-WEBSTER’S INT.DICTIONARY
The application of Mechanical laws of living structures, specially to the loco motor system of human body”.
Definition of Bio-Mechanics
"The area of study where the knowledge and methods of mechanics are applied to the structure and
function of the living human system"
"Bio-mechanics is the science concerned with the internal and external forces acting on a human body
and the effects produced by these forces.
KINESIOLOGY is the scientific study of human motion. The words kinesiology is taken by the combination
of two Greek words-
KINESIS - Movements or Motion
LOGIO - To speak-kinesiology means the science which speaks of movement
or motion.
Movement - "Change in location or position the body."
Analysis - "It splitting up an object matter movement into its constituent parts
or elements is called analysis".
Example - Long Jump (Constituent parts are)
(i) Approach Run (ii) Take Off (iii) Movement in Air (iv) Landing
KINESIOLOGICAL ANALYSIS
“Kinesiological analysis seeks to identify the joints, muscles and the body levers involved in execution of a
given skills (movements) as well as the sequence and degree of their involvement”.
It involves the following steps.
1. Descriptive (Purpose and classification of movement)
2. Anatomical Analysis
3. Mechanical Analysis
4. Recommendation based on the first three steps for the further improvement of performance.
Example - Standing long jump.
1) Descriptive purpose - To cover a greater horizontal distance in a single leap by
take off by two leg.
Classify Motor Skill
1. Imparting impetus
2. Movement in air
3. Receiving impetus (landing)
2) Anatomical Analysis
1. a) Joints – What all joints involved
1. Range of movements
i) Muscles-
i) Involvement of muscles in movements.

3. iii) Types of contraction
iv) Effect of contraction (full, medium or less)
3) Mechanical Analysis - Identification of mechanical principles for execution of S.B.J.
Body become projectile
1. Take-off angle
2. Velocity
3. Maximum force take off
4. Direction of force
5. Sufficient friction
6. Sequence of body movements
7. Contribution of leg and arm movements
8. Lever involve
Why Kinesiological Analysis ?
1. An aid to effective teaching of skills.
2. Kinesiological knowledge enable teacher to diagnose any difficulties of each students
performance with an “X ray eye”
3. Make aware type of injuries occurs in particular motor skills, and suggestion for prevention
4. Identification of categories.
Basic Terms
MECHANICS is that branch of science which studies the motion or form of bodies under the action of
forces.
BIOMECHANICS - is the field of study which applies the principles of mechanics to the structure and
movement of living things.
SPORTS BIOMECHANICS - is the application of the principles of biomechanics to the study of human
motion in sports and exercise.
Bio-Mechanics - has two branches
Kinematics - Descriptive nature of movement
Kinetic - Cause of Motion
"It is the process of identification the Kinematics characteristics as well as kinetic basis of the movement
structures".
Example - 100 mts.
Kinematics - It is characteristic of movement pattern.
i) Change in velocity
ii) Maintenance
iii) Declaration
One moves due to force from ground.
Kinetic i) How much force get from ground in running direction.
Two types of Analysis
i) Qualitative
ii) Quantitative
i) Qualitative - Concern with only identification of observable characteristics or performance is evaluated
subjectively.
a) It is based on the visual observation of result or performance. Some time observation may be aided by
instrument like Video-recording, because some time eyes are not able to catch total movement. Then
Video recording enhance the analysis.
In its more complete form, the method consists of a systematic evaluation of not only the results but also
of all the various factors that have contributed to result".
Example "Drive your chest forward and upward as you take off".
The advice is probably based on the coach's knowledge.
Uses of video-recording Polaroid sequence camera or a motion picture camera. – (result is not altered by
the use of such aids)
ii) Quantitative Analysis - is based on measurements taken from a recorded the performance. It is
basically objective.

4. "It is identify the factors that determine success in the performance of a motor stalls.
In Quantitative analysis - The performance is first recorded using photographs, cinematography,
electromyography or some other recording technique, than is evaluated objectively on the basis of
measurements taken from the record(s).
Example- study of sprinting
High speed motion picture film and analyze these frame by frame to determine such quantities as the
horizontal and vertical velocity of the C.G. at critical instants through the sequence of motion. – at the
instant of touch down and take off for each ground support phase.
We obtain some values or data and that data further treated for scientific interpretation for generalization
and for statistical analysis"
Required
1- Expensive equipment
2- Highly trained people
3- More time
With Quantitative analysis, researcher would reach conclusions concerning the factors that determine
success.
Bio-Mechanics in Physical Education, Sports & Research
1. Diagnostic technique
2. Diagnostic Coaching
3. Reference system development (as result IBM
4. Comparative Research (Reference system)
5. Applied Research (Other form of Research applied)
6. Experimental Research (Compute simulation technique)
7. Development of basic fundamental movements
8. A organization of development of motor abilities
9. Development of efficient sport techniques
10. B.M application help posture development
11. Development of sport equipment and facilities (acceptance of new equipments & changes in
rules)
12. BM application with regards to specific spent- medicine problems.
13. BM-contribute-body knowledge of sports-or theory of sport training.
Bio-mechanics is applied at all level of training and at all age.
Fundamental Skill
In the form of daily life activity or sport activity there are two types.
 Basic fundamental Skill – Which are develop from the childhood through the incoming years
and which have the objective of meeting the daily life activity or which essential for daily life
activity. Such as running jumping lifting carrying walking etc.
 Sports Skill – These are the constituent of a particular sports which are named as techniques as
a sports like the fundamental skill of Basketball-dribbling shooting, passes etc.
Each game composed of various skill and combination of these skill give rise to tactics.
Basic movement ensure efficiency of General movement pattern. If a person have mastery over the skill
is more of that person.
 basic movement ensure efficiency of General Movement Pattern. If a person have mastery over
basic movement than the chances of mastery over the skill is more of that person.
 Basic movements are to be developed in the initial stage of age – 10-15 stall learning is to be
started.
 It is the duty of PT to develop Basic skill movement so as to develop the required co-ordination,
posture etc. e.g. Walking style - Once the movement automat zed it is diff to change. Thus the
PT correct the fault in basic movement in initial stage of age sport skill are having nature of
complex demand high co-ordination speed, flexibility- Acquired as folder

5. Rough - coordination
Fine - coordination
Automatisation execution
Mechanical Analysis – “is the process of identify all the laws and principles of mechanics. “A branch of
physics which deals with motion and force which comes into play during the execution of a given motor
skills of movement of a sports skill”.
Example – Spiking –Complex technique- require co-ordination ability – split up in its constituent phases –
1) Approach 2) Take off 3) Movement in the air
4)Hitting the ball 5) Landing
1) Approach – There stride approach and last stride longer the previous one with both the feet
together to get Heel-ball-toe action-result to get leaner momentum (MXU) and last step change the linear
momentum into angular momentum.
2) Take off – is result of ground reaction(New or III law) - Force + momentum
Force + Arm action
Take of Force
Take of angle
3) Movement in the air – Person arches back to acquire dynamic stability when the body is without
supports (Law of end & middle law) when end move forward middle move backward use
4) Hitting the ball - with straight arm or stretched VL=WR – the linear velocity of the ball
5) Landing - stable landing – shock absorplia by landing the knee.
Mechanical Analysis – data acquisition – data reduction – transfer raw data into useful form organized
condensed.
Photographic Analysis System
A Cinematographic data reduction system includes the devices and routines involved in diglizing and
mathematical analysis of film data.
Digitizing system used to put visual image into digital or numerical form, can be classified as these involve
(i) Paper & pencil procedure (ii) Mechanical devices and procedure
(iii) Electronic devices and procedure
1) Paper & Pencil technique -
a) Body Contour technique
b) Point & line technique
 Body Contour technique - Tracing the contour of the body outline on the paper. A workable
image size should be projected on a sheet of paper 8.5” inches and drawn. These drawing can
be done on transparencies.
 Point and Line or stick figure technique - Joint are used to indicate joint centre or other
anatomic land a mark and lines connecting these points indicate the body segments – Angle
formed various segments can be scaled directly.
2) A Mechanical digitizing devices - Mathematically analyzed.
3) Electronic digitizing devices – It can be interface directly.

6. Bio-mechanics
Linear Kinematics
Distance and Displacement
When a body changes it position from one point to another. The distance represent the length of the path.
“It represent the magnitude of length- Distance”.
“Distance covered by the body during the motion” or
“Total path covered by the body during the motion”.
Displacement - If the distance covered in straight line between the starting and end line is called
Displacement or
Minimum distance between two points.
Minimum distance or straight line jointing initial and final position.
Displacement refers the direction as well as magnitude.
Displacement may to zero or less than distance or equal
.
Speed - “The rate of change of position with time.
Distance covered in per unit time. Average Speed of the body is obtained by distance it covered by time. It
take to cover that distance.
Speed is a scalar quantity.
Velocity - It is vector quantity. it has both magnitude as well as direction.
“Velocity is defined in as rate of change of motion of the body in a particular direction.
Average velocity – Distance conerved /unit time in a particular direction “Dividing displacement by time
taken”
“ Velocity is also understood as rate of displacement or displacement per unit time”.
Acceleration - The term acceleration again represent a vector quantity.
“It is define as the rate of change of velocity”.
“The rate of which the velocity of a body changes with respect to time is known as its acceleration.
Average acceleration = Change in velocity
Time taken
= Final velocity – initial velocity
Time taken
ā = VF-VI
t
ā = Average acceleration
VF= The final velocity
Vi= The initial velocity
t = Time taken
If u is initial velocity & v is final velocity of an object & it take time t for velocity to change from u to v then
acceleration is represent by ā = v-u = m/sec./sec.
t
If there is acceleration, there is change in velocity. There are two possibilities-

7. 1. Velocity may increase or decrease.
The acceleration may be + ive (increase) –ive(decrease) with regard to linear motion may called
deceleration .
Acceleration due to gravity
All objects on or near the surface of the earth attracted toward it by gravity.
As object goes up the velocity reduces due to gravity is called retardation.