Tennis - Motion analysis

The sequence of movements of a correctly executed tennis stroke is subject to the biomechanical rules of rhythmic spiral kinetics. A basic knowledge of this will help you to play better.

In nature, according to the laws of rhythmic spiral kinetics (-dynamics), every movement consists of an initial counter-swing and the subsequent directional swing. This bipolar movement pattern is the basis for the loop movements of all tennis strokes. In the backswing, the counterswing is performed with the racket turning away from the target. During this phase, plenty of kinetic energy is collected, which is then released during the targeted stroke. Finally, a backswing movement takes place, which is again turned away from the target.
Ideally, the loop movement is executed in a harmonious sequence of movements. In the following series of pictures, tennis professionals illustrate the biomechanics presented. We took the pictures during the Wimbledon Tennis Championships 2009 in London.

The serve
Procedure: Stand behind the baseline - throw the ball with outstretched arm - back swing of the club - slight knee flexion - strong overstretching in the hollow back - club deep behind the body - continuous fixation of the ball - hit the ball at the highest point of the body extension - swing out with club guidance over the mutual shoulder - lunge into the playing field. Serena Williams demonstrates the service below.
The Forehand
Sequence of events: Racket in the forehand grip - early and wide return of the racket above head height - place the opposite leg as a supporting leg in front of the body - go deep into the knees - continuous fixation of the ball - start the stroke movement behind the body from top to bottom - stretch the opposite arm in the direction of the ball trajectory - hit the ball as far as possible in front of the body - while doing so, stretch the body - swing out over the opposite shoulder - step forward. Nicolas Kiefer shows a perfect forehand stroke.
The backhand
Sequence of events: Backhand grip - early and wide return of the club to head level - place the leg on the same side of the club in front of the body as a supporting leg - turn the body a good 90 degrees to the backhand side - get down on your knees - look at the ball over the shoulder of the club - start the stroke movement behind the body from top to bottom - hit the ball as far as possible in front of the body - stretch the body and straighten up to the hollow back - swing the club high above your head - step forward. Roger Federer now performs a good backhand stroke.

The Butterball
Sequence of events: Racket in forehand grip - return the racket to the back over the head - place one leg in front of the body - turn the body slightly to the forehand side - kneel slightly - look at the ball - "grab" the ball with the stretched, free arm in the direction of the ball - for the stroke movement, stretch the body and lead the racket upwards - hit the ball over and in front of the body - swing out loosely to the opposite side - find a firm stand. Tommy Haas finally shows the forehanded butterball.
Without a backswing, i.e. without returning the club, played with the forehand or backhand volley because of flying balls.
Sonja gives more tips on tennis on her page My Tennis Ground Rules.