Biomechanical Analysis of the Tennis serve

1. Biomechanical Analysis of the Tennis serve

2. Preparation The preparation phase primarily consists of the mental set in which the athlete prepares mentally for the skill he/she is about to perform

3. Preparation Head is stable and eyes are intently focused on the target. Shoulders and trunk are rotated. This will allow force production in next phase Balance – Good base support Left foot points at tennis post. Right foot Parallel with base line

4. Wind Up The purpose of the wind-up is to produce FORCE. Force Summation results in the production of a tremendous amount of force and momentum.

5. Force Summation Use of long levers in the racquet arm Timing of body segments Large muscle groups first

6. Wind Up During the course of the windup the athletes weight is initially shifted from the front foot to the rear foot. Concurrently the left arm tosses the ball; consistency is imperative to the performance of the serve. The left arm carries up to a fully extended position and aids concentration on the ball. The purpose of the wind up is to store elastic potential energy and then to convert it into Kinetic energy

7. Wind Up The action of the non-racquet and racquet arm is an example of Newton’s third law: ‘every action has an equal and opposite reaction’. The action of the left arm balances that of the right arm so that the racquet arm does not initiate unwanted angular momentum Weight is shifted to the back leg, knees are bent, this enables the use of ‘Ground Reaction forces’.

8. Wind Up This enables him to generate more thrust against the ground therefore generating a more powerful jump into the air. This concept is known as ground reaction force As the action of the arms and torso occur the weight is shifted from the rear leg back to the front leg and the knees are bent in order to develop force summation with the large lower body muscle groups.

9. Force Generation‘the hit’ The striking action of the force generation phase is initiated via the extension of the legs and the downward acceleration of the tossing arm. According to Newton’s third law, as the athlete pushes against the ground, the earth pushes back up against the athlete with the same force, this is also known as a ground reaction force

10. Force Generation The sequential body movements of the hips, torso, shoulder, arm, elbow, forearm, wrist and racquet simulate the action of a whip. The body is comprised of a series of segments, which form third class lever systems. The Racquet arm is full extended to create the longest possible lever and there fore the greatest FORCE.

11. Force Generation Whip + Long Lever = Great Force The sequential body movements of the hips, torso, shoulder, arm, elbow, forearm, wrist and racquet stimulate the action oh a whip

12. Contact • The ball is contacted through the centre of the racquet. • The athlete can also apply top spin by flexing the wrist over the ball.

13. Follow Through Right shoulder pointing towards direction of ball. Indication of follow thru is in correct direction therefore direction of forces produced have been accurate Head is balanced and focused towards direction of ball Rotation of torso brings right leg around and on to the court Body is front on and ready to play next point

14. Comparisons Head position not focused on direction of shot Preparation Small base support, this will create instability during ball toss

15. Comparisons Lack of torso rotation, this will hinder the production of angular momentum Wind Up Counter balance of arms is ineffective due to position of racquet arm Lack of force Summation

16. The Hit Over rotation of torso creating instability COG outside the base support, result will be instability Left arm moving in wrong direction this will limit the whip effect and reduce the production of force

17. Follow Through COG outside of body Continuation of over rotation and instability causes server to overbalance Right leg moving trying to land inside under COG for balance. This is too far to the left and in a poor position to play next point