Tennis

General

• 17 million people in the United States participate in tennis at least once a year ( Fig. 76.1 ).

  

• 10 million people play tennis at least 10 times per year.

• 4.5 million youths play tennis annually.

Epidemiology of Tennis Injuries

• Injuries to the lower extremity and spine account for 50%–75% of all tennis injuries.

• Elite players tend to have more injuries to the lower extremities and spine, whereas recreational players incur more injuries to the lower extremities.

• Most lower extremity injuries are acute sprains. Upper extremity injuries are more likely to be chronic overload injuries.

Rules of Tennis

• The court:

  • Tennis courts are 78 feet long and 27 feet wide for singles play, 36 feet wide for doubles play.

  • The court is divided by a net 3 feet tall at the center.

  • The lines around the end of the court are named baselines and sidelines.

  • Service lines are drawn 21 feet from and parallel to the net. On each side of the net, the area between the service line, the net, and the sidelines will be divided by a center service line.

  • Each baseline is divided in half by a center mark.

• Scoring

  • A standard game is scored with the server’s score being called first:

    • No point – “love”

    • First point – 15

    • Second point – 30

    • Third point – 45

    • Fourth point – game

  • If each team or player has won three points, the score is “deuce.” After deuce, the score for the next team or player to win a point is “advantage.” If the player or team with advantage scores the next point, that player or team wins the game. If the opposing team scores before this, the score returns to deuce. Hence, a player or team must have a two-point margin to win.

  • An alternative method of scoring has the winner of the game winning four points. This type of game is called no-ad scoring. If both players gets three points each, then the person who wins the next, fourth, point wins the game, with no need to have a two-point margin.

  • There are different scoring methods in a set. The two main methods include “tie-break set” and “advantage set.” Before a match, the method of scoring must be declared.

  • In an “advantage set,” the first player to win six games wins the set (winner must have a two-game margin over the opponent).

  • In a “tie-break set,” the first player to win six games wins the set, provided the winner has a two-game margin over the opponent. If each player wins six games, for a score of six-all, a tie-break game shall be played.

  • A player or team concedes a point if:

    • Two faults are incurred during the service of the ball.

    • The ball bounces twice consecutively before the return.

    • The ball is returned and hits the ground or an object outside the court of play.

    • The player hits the ball before it crosses the net.

    • In doubles, both players touch the ball when returning it.

    • The player, player’s racquet, or clothing touch the net.

    • The player deliberately catches or carries the ball with the racquet or strikes the ball twice with the racquet.

  • A match may be played to the best of three or five sets.

  • The players or teams stand on opposite sides of the court. Players will change ends after the odd games of each set.

  • The server is defined as the player or team that puts the ball into play, and the receiver is defined as the player or team who is ready to return the served ball. Players will switch roles after each game. In doubles play, each team will designate a player to serve a game first. They will then alternate games, serving the ball accordingly. Additionally, they will identify a player to return the first served ball. This, too, will be alternated in subsequent games.

  • When serving a game, the server shall stand behind alternate halves of the court, starting with the right side every game. The server is allowed one fault each point. The second fault results in a loss of a point to the server. The ball should be served to the service court opposite to the server. The ball must be allowed to bounce once before the receiver striking the ball.

Physiology

• Tennis is a noncyclical anaerobic sport (10%–30%) with an aerobic recovery phase (70%–90%).

• Single rallies may only last 3–8 seconds, but complete matches may last 3 hours.

• Tennis requires physical elements of quickness, endurance, strength, flexibility, reaction time/speed, agility, and coordination.

• Heart rate for singles tennis can average >160 beats per minute. Some skilled tennis players may average >80% of their maximal heart rate during a match.

• Depending upon conditioning, age, gender, intensity of play, hydration status, and environment, a player may lose 0.5–2.5 L of water per hour of play.

• Conditioning

  • Aerobic fitness

    • Aerobic intervals simulate intensity of play. Thirty-minute sessions, three times a week are required, at a minimum, for a conditioning effect.

  • Anaerobic fitness

    • High-intensity training performed at near-exhaustion levels with short work/recovery periods in a 1:2 ratio to mimic the tempo of match play (i.e., 15 seconds of work with 30 seconds of rest).

  • Progressive resistance strengthening of key muscle groups serves to prepare needed muscles for each tennis stroke and builds the body’s tolerance for progressive tennis drills and match play. All muscles along the kinetic chain, including core muscle strength, are important for conditioning.

  • Functional mobility

    • Sufficient active range of motion of all joints in the kinetic chain is recommended to avoid injury at adjacent motion segments.

Equipment/Facilities

• Racquets:

  • Composition: Change in manufacturing materials has resulted in racquets that are larger, lighter, stiffer, and more powerful than racquets of the past. This predisposes some athletes to chronic overload injuries of the upper extremity.

    • Stiffness: Stiffness is the amount of bending a racquet does on ball impact. The more flexible a racquet is, the more time that is taken for the racquet to deform and return to its original shape. Flexible racquets decrease the shock of the impact and the vibrations felt by the player, which comes at a cost of power.

    • Sweet spot: Striking area of the racquet that provides the lowest transmission of vibrations to the upper extremity and allows for the ball to rebound with the highest velocity. The sweet spot will vary with each racquet and be dependent upon its size, stiffness, and shape.

    • Weight: Racquets currently on the market vary from 240 to 310 grams. Racquet weight and speed are factors that contribute to the velocity of the ball after impact.

    • Balance: Racquets with head weight equal to handle weight are considered balanced in regard to their geometric center and center of gravity. Alterations in this balance may allow for a racquet to be more maneuverable (handle heavy, head light).

    • Grip size: Scored 1–5 depending on circumference. The ideal circumference of the hand should equal the distance as measured from the tip of the ring finger to the proximal wrist crease. Materials may be added to alter the feel of the handle (less slippery) or to dampen vibrations felt after ball strike.

    • String material: Gut strings are more expensive and less durable than synthetic strings but provide better performance. String thickness is measured in gauges (16–18). A larger gauge string will be more durable but absorb less shock.

    • String tension: String tension is a very important part of the racquet. More loosely tensioned strings with longer ball dwell times will return more power at the cost of some control.

• Tennis balls:

  • Nonpressurized: Bounce created related to the thickness and suppleness of the rubber used to make the ball.

  • Pressurized: Bounce created is related to qualities of the rubber and the internal air pressure (which exceeds that of the external environment). Once the internal pressure is lost, the bounce will not be as high and the ball will feel “dead.”

  • A nonpressurized ball must be hit harder than a pressurized ball, which places more load on the arm.

• Tennis shoes:

  • Important characteristics of a tennis shoe include cushioning, stability, stiffness, and design of the outsole.

  • Consideration to the amount of pronation/supination that a player endures during play will affect the decision to choose a shoe with material of higher density placed medially (to prevent excessive pronation) or for a shoe with a higher cut (to prevent excessive supination). A player should choose a shoe with an outsole that reflects the playing surface. Grass surfaces tend to have less friction and be more slippery, requiring a shoe with more grip. Carpet surfaces tend to have more grip; therefore, a shoe with less grip should be chosen to allow more twisting and turning.

• Court surfaces:

  • Clay: Red clay, green clay. Loose surface causes the ball to lose speed rapidly and bounce higher. Allows increased time for opponent to reach/return the ball. Considered a “slow” surface.

  • Hard: Concrete, coated asphalt, Rebound Ace. Balls bounce low, giving hard-hitting players an advantage. Considered a “fast” surface.

  • Grass: Grass grown on hard, packed soil. Balls tend to slide and bounce low, making returns difficult. Favors the serve-and-volley player. Considered the “fastest” surface.

  • Indoor courts: Allow for year-round play.

  • Injury: Data are equivocal on the overall rate of injury across different court surfaces. Injury rates in the lower extremity increase if the player changes surface to one with which they are unfamiliar.

Tennis-Specific Mechanics