Fundamentals of Kinesiology And Biomechanics in Sports | Class 11 Chapter 8 Notes 2024

Last updated on August 24th, 2024 at 12:35 pm

Definition And Importance

Definition of Kinesiology

Kinesiology is the scientific study of human body movements. Applications of Kinesiology to human health include biomechanics and orthopedics, strength and conditioning, sport psychology, methods of rehabilitation, such as physical and occupational therapy, and sport and exercise.

According to Merriam-Webster, “It is the study of the principles of mechanics and anatomy in relation to human movement.”

Kinesiology is the study of human movements, performance, and functions by applying the sciences of biomechanics, anatomy, physiology, psychology, and neuroscience. 

Applications of kinesiology in human health include physical education teachers, the rehabilitation professions, such as physical and occupational therapy, as well as applications in the sports and exercise industries.

Definition of Biomechanics

Biomechanics is derived from the Greek words ‘Bio’ and ‘mechanics’. Bio means living things and mechanics is a field of Physics. Thus, it is a branch of science that deals with the forces related to body movements.

According to Herbert Hatze, “Biomechanics is the study of the structure and function of a biological system by means of methods of mechanics.”

According to Miller Keane, “Biomechanics involves the application of mechanical laws to living structure.”

According to Farlex Partner, “It is the science concerned with the action of forces, internal or external, on the living body.”

Biomechanics can also be defined as the systematic study of the mechanics of body joints. It is a study that gives us knowledge about human body movement and the forces that act on human movement.

Biomechanics gives us an understanding of human movement while different forces act upon it. This subject gives us a better understanding of physics principles acting on the human body like laws of motion, levers and their types in the body, equilibrium application on the body, the role of gravity over the body, various forces acting on the body, projectile, aerodynamics and its role in sports, etc.

Importance of Biomechanics and Kinesiology in Sports

(i) Understanding Human Movement: Kinesiology and Biomechanics give us a better understanding of human movements and its impact on various systems of the body.

(ii) Improves Technique: Kinesiology and Biomechanics help to improve techniques, thus better-skill performance. Their knowledge helps us to perform the technique in a better and more efficient way.

(iii) Knowledge about Forces acting on the Body: These give us knowledge about various forces acting upon the body and their impact on various systems of the body.

(iv) Improve Performance: These help to improve the performance of individuals by developing good techniques and training methods.

(v) Efficient Movement: Make our body movements efficient & develop good practice skills.

(vi) Correct Movement: These correct the faulty movement so that the movement becomes effective and efficient.

(vii) Prevent Injuries: Knowledge of Kinesiology and Biomechanics helps to reduce injuries and, moreover, prevent the cause of injury through movement.

(viii) Knowledge about Physics Principles: They give us knowledge about physics in relation to human movements like principles and laws of motion, lever and its types in the body, equilibrium, various forces, projectile, aerodynamics, etc.

(ix) Guide Safety Principles: These subjects guide us about the safety principles and give us an idea of how to reduce injuries and follow preventive steps.

(x) Help in the Research Works: Biomechanics principles help in the research work and direct scientific approach through scientific ways.

(xi) Improve the Designs of Sports Equipment: These also help to improve the designs of sports equipment through scientific ways.

(xii) Help in Developing New Tools: Biomechanics helps to develop new apparatus and tools for the help of human movements.

Principles of Biomechanics

(i) Principle of Stability:

According to it the lower the center of mass, the larger the base of support, the closer the center of mass to the base of support, and the greater the mass, the more stability increases.

(ii) Principle of Maximum Velocity:

According to this principle, the production of maximum velocity requires the use of joints in order from largest to smallest. Like hitting the ball in hockey, or passing shot (tennis). hitting a golf ball etc.

(iii) Principle of Linear Motion : 

This principle says that the greater the applied impulse, the greater the increase in velocity. Movement usually occurs in the direction opposite that of the applied force. 

Linear motion simply means motion in a straight line (as opposed to circular motion or rotation) like in slam-dunking a basketball, cyclists, runners, etc.

(iv) Principle of Angular Motion: 

According to this, the angular motion is produced by the application of force acting at some distance from an axis, that is, by torque. The principle is also known as the principle of the production of angular motion. 

Like a high jumper takes a curved path to gain speed for a vertical jump, baseball pitchers, and cricket pace bowler rotates his/her arm fast to produce greater angular motion so that he/she can throw fast.

(v) Principle of Angular Momentum :

Angular momentum is constant when an athlete or object is free in the air. This principle is also known as the principle of conservation of angular momentum. 

An athlete will travel with a constant angular momentum while doing throwing games like a shot put or discus, and a Hammer’s thrower rotates or spins around his/her body fast to produce greater angular momentum so that he/she can throw farther.

(vi) Maximum Effort:

The production of maximum force requires the use of all possible joint movements that contribute to the task’s objective.

(vii) Principle of Aerodynamics:

According to this, the body should be in a streamlined position to move fast. Like Cyclists keep the body compact and in line to produce less friction and drag force.

Types of Body Movements

Flexion: 

Flexion is a bending movement that decreases the angle between a segment and its proximal segment. Flexion is a movement in the anterior direction. For example, bending the elbow, when down, the knees get flexed. 

Flexion of the shoulder or hip refers to the movement of the arm or leg forward,

Flexion of the truck refers to bending forward. Bending the leg back for kicking is flexion of the leg. We move the arm curling up with a dumble is flexion of the arm. Bending of the neck in the front direction is flexion of the neck.

Extension: 

Extension is the opposite of flexion, describing a straightening movement that increases the angle between various body parts. An Extension refers to movement in the posterior direction.

For example, when standing up, the knees are extended. In an extension of the hip or shoulder, we move the arm or leg backward. Bending back is an extension of the trunk, and kicking the ball is an extension of the leg. 

Lowering the arm during curling down is an extension of the arm. Bending the neck at the back is an extension of the neck.

Abduction: 

Abduction refers to a motion that pulls a structure or part away from the midline of the body. For example, raising the arms to the side-ward is an example of abduction at the shoulder. When the legs are split wide it is the abduction of the hip.

Adduction: 

Adduction refers to a motion that pulls a structure or part towards the midline of the body, or towards the midline of a limb. For example, lowering the arms from the side is adduction of the arm, and Bringing the legs close to the body from split legs is adduction of the hip.

Rotation : 

Rotation is the movement in which a bone or a whole limb, pivots and revolves around a single long axis.

(a) Internal Rotation (Medial Rotation): It refers to rotation towards the inner side of the body.

(b) External Rotation (Lateral Rotation): It refers to rotation away from the center of the body.

Circumduction : 

Circumduction is a combination of flexion, extension, adduction, and abduction. It refers to a conical movement of a body part, such as a ball and socket joint. Circumduction can be best performed at ball and socket joints, 

For example, circumduction occurs when spinning the arm while performing a serve in tennis or bowling a cricket ball.

Pronation: 

Pronation is the position in which the anatomical position of the forearm is rotated so that the palm of the hand faces backward. In this, the elbow is flexed so that the forearm becomes horizontal and the palm of the hand is turned to face downwards. Prone is lying or positioned on the tummy.

Supination: 

Supination is opposite of pronation. The palm of the hand is turned to face forward or upwards if the forearm is horizontal. Supine is lying or positioned on the back.

Concept of Axis and planes and their application in body movements

Movement refers to a change in the position of an object. In the human body, it takes place when the living organism moves a body part or a combination of parts without a change in the position. 

The term locomotion is used to describe the movement which brings a change of position of the whole organism. Movement is the displacement of a body or its parts from their original position to a new position. 

Locomotion is when the movement of a part of the body leads to a change in the position and location of the organism. Both of these are brought about by the joint efforts of the skeletal and muscular systems. Human movements are described in three dimensions based on a series of planes and axes.

Plane

A plane is an imaginary surface through which movement takes place. There are three planes of motion that pass through the human body.

(i) Sagittal Plane:

The sagittal plane is an imaginary vertical surface that divides the body into right and left parts or sections. Flexion and extension types of movement occur in this plane, e.g., kicking a football, chest pass in netball/basketball, walking, jumping, squatting, etc.

(ii) Frontal Plane:

The frontal plane is also an imaginary vertical surface that divides the body into front (anterior) and back (posterior) parts or sections. The frontal plane is also known as the Coronal plane.

Abduction and adduction movements occur in this plane, e.g., jumping jack exercises, raising and lowering arms and legs sideways, cartwheel, etc.

(ii) Transverse Plane:

The transverse plane is an imaginary horizontal surface that divides the body into upper (superior) and lower (inferior) parts or sections.

Rotation types of movement occur in this plane, e.g. hip rotation in a golf swing, twisting in a discus throw, pivoting in netball/basketball, spinning in skating

Axis

An axis is an imaginary straight line around which an object/part of the human body rotates.

Movement at a joint takes place in a plane about an axis. There are three axis of rotation.

(i) Sagittal Axis:

The sagittal axis is also known as the anteroposterior axis or the dorsoventral axis. It is an imaginary line that passes horizontally from the back (posterior) to the front (anterior) through the center of the body. It is formed by the intersection of the sagittal and transverse planes. e.g., when a person performs a cartwheel, he is rotating about the sagittal axis.

(ii) Frontal Axis:

It is also known as the horizontal axis or left-right axis. The frontal axis is an imaginary line that passes horizontally from left to right through the center of the body. 

It is formed by the intersection of the frontal and transverse planes. e.g., when a person performs a somersault, he rotates around this axis.

(iii) Vertical Axis:

The vertical axis is also known as the longitudinal axis or craniocaudal axis. This axis is an imaginary line that passes vertically from the bottom (inferior) to the top (superior) through the center of the body. 

It is formed by the intersection of the sagittal and frontal planes. e.g., when a skater performs a spin, he rotates around the vertical axis.

Kinetics And Kinematics in Sports

Kinetics in Sports:

• Kinetics deals with the forces that affect the motion of objects. In sports, it’s all about how forces influence athletes and their movements.
• For example, when a baseball player swings the bat, the force they apply determines the speed and trajectory of the ball.
• Understanding kinetics helps coaches and athletes optimize performance by analyzing and improving their techniques and strength.

Kinematics in Sports:

• Kinematics, on the other hand, focuses on the motion of objects without considering the forces that cause them to move.
• In sports, kinematics helps describe and analyze an athlete’s motion, such as speed, acceleration, and direction.
• Video analysis of a sprinter’s running motion is an example of using kinematics to identify areas for improvement in their technique.

Combining Kinetics and Kinematics:

• When kinetics and kinematics are combined, coaches and sports scientists can get a comprehensive understanding of an athlete’s performance.
• By analyzing both the forces involved and the resulting motion, they can identify areas where an athlete’s strength or technique can be enhanced.
• This knowledge is valuable for injury prevention, skill development, and achieving peak performance in various sports.

Remember, understanding both kinetics and kinematics allows coaches and athletes to fine-tune their skills, maximize performance, and stay at the top of their game

Final Words

From the above article, you have learned about Kinesiology and Biomechanics and the application of Kinesiology sports. We hope you get knowledge about the whole topic in brief but this much note is enough to pass your exam.

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