Tennis is an indoor or outdoor game, played by two players or two pairs of players, using rackets and a light ball, across a rectangular court, which is divided in the middle by a net. It is called singles when there are two players and doubles when there are two pairs. There are white lines in the tennis court, which indicate the dimensions and service areas. The standard tennis court measures 78 feet long and divided into two equal sides. The net at the center measures approximately 3 feet. For doubles, alleys 4.5 feet wide are added along the two longer sides, increasing the total width to 36 feet. Courts may be made of grass, clay, wood, asphalt, concrete or other synthetic material. (USTA 2002) The tennis ball, on the other hand, is 2 1/2 and 2 5/8 inches in diameter and weighs between 2 and 2 1/16 oz. It is made of wool and artificial fibers and is usually either white or yellow. And the rackets used are generally classified by the size, which is standard, mid-sized, oversized or super oversized. (USTA) The referees in recreational contests are usually the players themselves, but officials in tournaments keep score, judge shots as good or not and interpret rules. The chair umpire heads the judges and sits on a tall chair in one end of the net, while the other line judges sit around the court and away from the movement area of the players. These line judges decide whether the serves and shots are good or not. A net-cord decides when a ball touches the top of the net, while a foot-fault judge watches for specific violations. Electronic devices are now used in professional tournaments to determine if serves, whose speed is more than 100 mph, land in or out of the service box. (USTA).

A b.

The main objective of the game is, of course, to win it. The game is played up to four points and won by two points, designated by the scores 15, 30,40 and zero (referred to as love). A tie that reaches 40 is called a deuce, and the player, who reaches a deuce and makes a point after it is the winner through the "no-ad" system. Players aim at winning 6 games in a set and by minimum of 2. They must win at least 7 in the set in case of a tie at 5-5, which then requires an extension. Competitions usually require two wins out of 3 or3 out of 5 sets.

IIa. The game begins with a serve and the server is the player who initiates by tossing the ball into the air and hits it before reaching or touching the ground and into the opponent's service area, which is called the service box. The player who receives the ball is called a receiver. The server must do so behind the baseline and outside the court until the ball is hit or struck. The first serve is done at the right side of the court and two tries are allowed per service. A fault is called if the ball first hits any part of the opponent's court (except the service box) or goes out of court or hits the net before hitting the opponent's court outside the service box or before getting out of court. First serves usually have more velocity, while second serves have greater accuracy and more spin.

b. In case of fast serves, players usually go behind the baseline to have more time to react. After the first point, the service is done at the left side. The service is thereafter made on the opposite side as the points are earned until the entire game is played. The opponent then serves in the succeeding game, with this alternating pattern of service. In the case of doubles, the serves are done alternately between teams and between players, with an individual player serving every fourth game.

The ball is struck back and forth until a player or side fails to return it successfully. When a player lets it bounce twice, hits it into the net or outside the boundary of the opposite side, that shot is considered unsuccessful. If it strikes the line of the court, it is considered in play. Or it falls out of bounds on the opposite side after hitting the net, it is called out. It is also considered in play if it falls into the opposite court. And when the strike is unsuccessful, the opponent gets the score.

A c.

A follow through is a kind of "verification" of the type of hit or strike made, which in turn, depends on the amount of time of a forward swing, the court space when making the hit, and...

Nonetheless, the idea that there is a certain height or length to all follow-throughs hides the simple fact that the ball has changeable speed and heights, as changeable as ball placement, hitting power and depth.
IIIa-c The chief body parts involved in the game of tennis are the head, the shoulders, the heart, the elbows, the abdomen, the arms (and shoulders), the hands and wrists, and the legs. The head contains the brain or the mind, which controls the body and its movements. It produces the thoughts that turn to action, develops strategies of the game, visualizes and commands the specific body parts to strike or move. It observes feedback, retains, processes and forms a judgment out of what it observes or experiences. It also controls the emotions that in turn control the person himself. The head contains the eyes that look at the ball, other players, conditions and the judges' signals, and the neck that pivots or tilts.

The shoulders and the neck are made up of muscles that stabilize these body parts as well as provide the power to strike and decelerate that power. They connect the controlling brain to other parts of the body.

The chest contains the most important muscle in the body, which is the heart.

The heart pumps energy into the body through blood circulation. The needed nutrients for the game are also circulated by the blood to other muscles, which release energy for activity. Blood also removes waste products away from these muscles. It also maintains proper body temperature by dissipating heat. In combination with the arms and shoulders, the chest generates power through the trunk and legs. It is here where the adjustment for strokes is made or exerted.

The elbows are joints that flex when flexing or bending is needed to hit the ball or perform related activities. In the process of flexing and un-flexing, the player may develop tennis elbow, which is a sore and painful condition of the outer part of the elbows. This results from a chronic overload of the wrist extensors, or those muscles responsible for bending the wrists backward.

Players must avoid motions that induce or recreate the pain.

The abdomen (or abs) and the trunk develop rotational forces and channel power from the feet to the racket. These muscles are, therefore, of critical importance in a power game like tennis. A good weight-training program will strengthen these muscles up to 85% of one's maximum strength levels. Sit-ups, trunk twisting, seated rowing and latissimus pull-downs are the precise exercises or training for these muscles.

The hands and the wrists that join the hands to the arms, in turn, deliver the power generated by all the body parts. They also control the stoke itself, respond to or counter the force of ball contact and develop "head speed." For power. (Papas 2002)

And the legs are definitely inevitable in the game, as they are responsible for all movement and the creation and delivery of a powerful stroke. The legs are kept in optimum condition by both aerobic and anaerobic conditioning exercises.

Equilibrium results when the body is at rest or in un-accelerated motion, wherein all the forces acting on it - and the sum of all torques on the axis -- are zero. The body is said to be balanced, and the body that is physically balanced is strong (Papas). This kind of balance is seen in dance and self-defense, such as the ballet and martial arts. Its physical structure is more easily applicable to tennis than to other sports, such as golf and baseball.

Balance is defined as movement, posture and then final position. This happens when the shoulder line and the hip line are parallel to the ground below; the torso is straight and the shoulders are moved back and relaxed; and the hips tucked under in a forward position, with the tailbone downward. Gravity is the center of the body (the groin area), and when you move, you move the center of the body. This is the most efficient way of moving..The common and inefficient way of moving is when the torso leans over first and then the body…