Biomechanics and Sports Flashcards
In primary and high schools, stress is laid down on
learning the fundamental motor skills, which provide a base for the learning of advanced sports skills.
Biomechanics
Biomechanics is a subdiscipline of physical education. The term ‘biomechanics’ is a combination of two words i.e., ‘Bio’ and ‘mechanics’. Here ‘bio’ is a Greek word that refers to life or living things and ‘mechanics’ refers to the field of physics and the forces that ac on bodies in motion. Hence, “The study and analysis of human movement and patterns in sports is called biomechanics.”
The three laws of motion were formulated by
Newton
Law of Inertia
It is the first law of motion. According to this law, “A body at rest will remain at rest and a body in motion will remain in motion at the same speed and in the same direction unless acted on by an external force.”
Law of Acceleration
It is the second law of motion. According to this, “A change in the acceleration of an object is directly proportional to the force producing it and inversely proportional to its mass.”
Example in sports - Hammer throw, the thrower, who is stronger(who has more force), will throw the 12 lbs hammer farther than a thrower who has less force or strength. If a baseball player hits a ball with the double force, the rate at which the ball will accelerate will be doubled. Football players can slow down, stop or reverse the direction of other players depending upon how much force they can apply and in which direction.
Law of Reaction
It is the third law of motion. According to this law, ‘For every action, there is always an equal and opposite reaction.’
Applications of the third law of motion.
(a) Swimming: A swimmer pushes the water backwards (action). The water pushes the swimmer forward (reaction) with the same force.
(b) Walking: When a person walks, he/she presses the ground in the backward direction (action) by his/her feet. The ground pushes him/her in the forward direction with an equal force (reaction).
(c) Shooting: In shooting, when a gun or pistol is fired, the bullet moves forward (action). The gun or pistol jerks backward (reaction).
(d) Dribbling in Basketball
(e) High jump: A high jumper can jump higher off a solid surface because it opposes his/her body with as much force as he/she is able to generate, in contrast to sand or any other unstable surface.
Equilibrium
When all the forces acting on a body are counter balanced by equal and opposite forces, so that the sum of the forces equals zero, it is called the state of equilibrium.
A state of equilibrium occurs when the body’s center of gravity is
over its base of support and the line of gravity falls within the base.
Types of equilibrium
- Static equilibrium- Static equilibrium is when the center of gravity is in a stable position, e.g., when one is sitting or performing a handstand in gymnastics.
- Dynamic equilibrium- is a state in which the center of gravity is in motion, e.g. when one is running or performing a cartwheel in gymnastics.
Principles of stability
- The lower the center of gravity is to the base of support, the greater the stability.
- The nearer the center of gravity is to the center of the base of support, the more stable the body.
- Stability can be increased by widening the base of support.
- Stability is directly proportional to the weight of the body.
Center of Gravity
A center of gravity is an imaginary point (within or outside the body or object around which the body or object is balanced. It always shifts in the direction of movement.
Friction
Force of friction is the force that develops at the surfaces of contact of two bodies and opposes their relative motion.
There are two causes of friction-
Firstly, the roughness or irregularities of surfaces, and secondly, the strong atomic or molecular forces of attraction between the two surfaces at the points of actual contact.
Types of friction
- Static friction: The opposing force that comes into play when one body tends to move over the surface of another, but the actual motion has not yet started, is called static friction.
- Dynamic friction
