Physical Education Class 12 Notes Unit 8 Biomechanics and Sports
→ Meaning of Biomechanics: Biomechanics is the study of science that examines the internal and external forces acting on a human body and the effects produced by those forces.
→ Importance of Biomechanics in Sports:
- Improves performance in sports,
- Improvement in training technique,
- Development of improved sports equipment,
- Prevents sports injuries,
- Helps in understanding human body,
- Knowledge of safety principle
- Helps in research work,
- Creates confidence in player,
- Helps in maintaining healthy body,
- Increases the popularity of sports
→ Types of Movements: Joints movements are divided into four types:
→ Gliding Movement: Movement of one surface over another without any angular or rotary movement.
→ Angular Movement: Movement which is produced by changing the angle between the bones of a joint.
→ Different types of angular movements are:
→ Flexion: It refers to a movement that decreases the angle between two body parts (bending the elbow or knee).
→ Extension: It is opposite of flexion, describing a straightening movement that increases the angle between body parts (bending of the head backward).
→ Abduction: It is a movement in the frontal plane about the sagittal axis and involve moving the body part away from the central line (abduction of the shoulder raises the arm out to the sides of the body).
→ Adduction: It is a movement in the frontal plane about the sagittal axis and involve moving the body part towards the central line, (returning the arms straight out at the shoulders to the side of the body).
→ Circumduction: It is a compound circular movement which involves flexion, abduction, extension and adduction at a joint.
→ Rotation: It is the form of movement in which the bdne moves around a central axis without experiencing any displacement from this axis.
→ Newton’s Law of Motion and Its Application in Sports
→ Newton’s Law of Motion:
→ First Law of Motion/Law of Inertia: This law states that a body at rest will remain at rest and a body in motion will continue to remain in motion at a constant speed and in the same direction until any external force is applied on it to change its state.
→ Second Law of Motion/Law of Acceleration: According to second law of motion, the rate of change in acceleration of an object is directly proportional to the force producing it and inversely proportional to its mass.
→ Third Law of Motion/Law of Reaction: This law states that to every action, there is an equal and oppsite reaction.
→ Application of Newton’s Law of Motion in Sports
→ First Law: Tennis: A tennis ball will remain at rest in the court until the unbalanced force of player’s hand picks it up and moves it. A tennis ball hit by the player will stay in motion until it hits the unbalanced force of opposing player’s racquet.
→ Second Law: Baseball: A baseball hat with a swinging bat will accelerate more than a baseball that is bunted because the swinging bat has more force.
→ If equal force is applied to the base ball (more mass) and t-ball(less mass), then the t-ball will accelerate more.
→ Third Law: Soccer: When a soccer ball hits a goalie’s hand, the action is the ball hitting the goalie’s hand and the reaction force is the hand hitting the ball in the opposite direction.