Biomechanical Analysis of the Tennis serve

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

PreparationHead is stable and eyes are intently focused on the target.

Balance – Good base support

Left foot points at tennis post.

Right foot Parallel with base line

Shoulders and trunk are rotated. This will allow force production in next phase

Wind UpThe purpose of the wind-up is to produce FORCE.

Force Summation results in the production of a tremendous amount of force and momentum.

Force Summation

Large muscle groups first

Timing of body segments

Use of long levers in the racquet arm

Wind UpDuring 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

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’.

Wind Up

As the action of the arms and torso occur the weight is shifted from the rear leg back to the frontleg and the knees are bent in order to develop force summation with the large lower body muscle groups.

This enables him to generate more thrust against the ground therefore generating a morepowerful jump into the air. This concept is known as ground reaction force

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 pushesback up against the athlete with the same force, this is also known as a ground reaction force

Force GenerationThe 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.

Force Generation

Whip

+

Long Lever

=

Great ForceThe sequential body movements of the hips, torso, shoulder,

arm, elbow, forearm, wrist and racquet stimulate the action oh a whip

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.

Follow ThroughRight 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

Comparisons

Preparation

Head position not focused on direction

of shot

Small base support, this will create instability during ball toss

Comparisons

Wind Up

Lack of force Summation

Counter balance of arms is ineffective due to position of racquet arm

Lack of torso rotation, this will hinder the production of angular momentum

The HitOver rotation of torso creating

instability

Left arm moving in wrong direction this will limit the whip effect and reduce the production of force

COG outside the

base support, result will

be instability

Follow Through

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

COG outside of

body