FACTORS AFFECTING MOVEMENT
Movement means change in position. For determining the movement it is necessary to
explain the basic factors that can effect the movement.
MASS
The motion of an object depends upon the mass of the body. Lighter body is easy to move whereas heavier body is difficult to move. Mass of the body is considered to be one of the important factors in the sports that can affect the performance of the player. The difference of the performance of lighter and heavier bodies can be determined from its nearness to the sea level arid at high altitude competition. It is quite.clear that heavy bodied athletes are not suitable in the events of short distance races.
GRAVITY
Motion of a body depends upon the value of gravitational field. Gravity affects different events cf athletics, such as the span of throws, jumps etc During motion with the center of gravity body changes conştantly. Weight of the body and centre of gravity of a player have importance in the field of sports. Gravity is another factor affecting motion.
EQUILIBRIUM:
The state of rest and uniform motion are called Equilibrium State. If a body is moving in such a way that it achieves the state of equilibrium, then its motion becomes uniform. If a body comes at rest then it is in a state of equilibrium. In the events of sports especially in Jumping, gymnastics, diving and vaulting accuracy and balance of body has got due significance. It means that the factor "Equilibrium" can affect motion.
Power
Ability to project a body or an object through space depends on power. The force and velocity increase power.
Flexibility
Flexibility depends on extensibility of muscles tendons and ligaments. it helps in full range motion. It is important for dancing, diving and gymnastics.
Force
Force can be defined as any influence that can change the state of a body. It is a product of the mass and acceleration of an object. A force can also be defined as a push or pull exerted against an object in an effort to start stop accelerate, decelerate, maintain or change its motion, the forces that cause the human body to move are produced internally by the muscles and externally by another person, a machine, an animal, the wind and by gravity etc. The effectiveness of a force is produced by the body.
There are two additional forces or factorss which affect the motion of a person or any object the centripetal and centrifugal force. Centripetal is a force directed inward the center of a circular path of motion. Centrifugal force is the inertia tendency of a body in motion to move out or away from the center of the circular path.
Energy / Muscular strength and power
Energy is required to produce force and move an object from one place to another place. The human body applies force in the form of muscular energy. This muscular energy may be applied directly to an object through a continual force such as pulling, pushing, carrying or lifting This energy of motion is called kinetic energy. The body may also apply forces to objects indirectly through the use of potential energy.
Friction
Friction is a type of resistance between the surface of two objects (resistance is an opposing force that makes it different to move an object). The amount of friction between the wo objects depends on the type of surface and the weights of objects. Rough surface causes more frictions than smooth one. Similarly heavy objects cause more friction than light ones. Friction is necessary to start and stop the motion e.g. some friction are must between the surface of an athletes shoes and play ground to gain motion and to stop it later. In some cases the amount of friction is considerably reduced for the purpose of efficient movement i.e. in case of ice skating etc.
Friction may be divided into three categories:
1. Static Friction:
When a person begins movement on an object is greater in amount and harder to overcome, he needs
more power, energy or force.
2. Kinetic Friction:
It exists when a person attempts to slide one object over another.
3. Rolling Friction:
When an object rolls one over another object it is called rolling friction.
Air Resistance
Air resistance is a force that is always present and slows the speed of a moving object because of the pressure of air around it. The effect of air resistance depends upon the size, shape and form of any object. Air resistance also affects the velocity or role of speed of an object e.g. fall of shuttle, balloon or hard ball etc.
Levers
In mechanics a lever is defined as a rigid bar. It is a simple machine, which helps to accomplish a task. This rigid bar or lever revolves or turns around a fixed point known as axis (A) with a force (F) to move it and a resistance (C) to be overcome by it. In the human body the bones represent the rigid bar and joints as axis (A) or fulcrum. The muscles of the body provide the force (F) and the resultant action is known as resistance or movement which occurs.
Classes of Levers
There are three kinds or classes of a levers determined by the relative arrangement of the Axes (A) the point of force F) and the point of resistance (R).
1. The first class lever has the arrangement as FRA for example seasaw.
2. Second class lever has the arrangement as FRA e.g. the door, when open with knob.
3. Third class lever has the' arrangement as AFR. The human body most oftenly uses a third class leverage system, e.g. throwing or kicking a ball.
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