Tennis: Sweet science finds kinetic power: Pro Kennex unleashes new racket to harness more energy and reduce risk of injury. Patrick Miles reports on an unusual application of aerodynamics

A GERMAN scientist three years ago turned his gaze to the sweet spot of a tennis racket. An application of physics led to the isolation of what he called the 'sweet point'. Then he turned the sweet point into a sweet area with kinetic energy and the rattling new Pro Kennex model was born.

Roland Sommer, an aerodynamics expert but 'not a sportsman', is a man with 50 patents. The idea of more efficiently harnessing the energy created when a swinging racket connects with a moving ball came to him when one of his friends, a pilot, complained of tennis elbow. He said not only was he unable to play tennis, he feared he would fail his medical.

Sommer designed a method of harnessing a kinetic reaction in the head of a racket that would stabilise the hitting area and eliminate the subsequent vibration. According to players who have used it, the sweet spot is far greater; and the pilot is flying and playing again.

Pro Kennex launched the Kinetic at London's Queen's Club yesterday. The company's slogan says 'It rattles and it's deadly'. It looks exactly like a present-day racket but when it moves, it not so much as rattles as plays a cha-cha. If you buy two (at pounds 200 each from today), you have maracas.

The sands of time - or in this case the tiny composite-metal particles whose exact nature is a secret - are shifting in tennis as the public eschews the power game. Last month, the International Tennis Federation said it would provide different balls for the different surfaces in the Grand Slams to change the speed of the game. But it has approved the Kinetic, and slightly amended its rules to accommodate it, because the design's emphasis is more on control than weight of shot. In Sommer's words: 'Power makes no sense. I need control.'

Using projected diagrams, a video of Rod Laver, plastic lollipops and a model train, he illustrated his points with enthusiasm.

As the racket swings forward, particles in chambers around the head are storing energy. When the ball hits the strings, they flex, the ball compresses and its speed drops to zero. The ball and strings are loaded with energy.

The frame flexes backwards as the swing continues. The ball assumes the racket's speed and the forces are in place to set off a kinetic reaction. The ball and strings release their energy, causing the ball to go faster than the racket. The release of energy from ball and strings triggers the kinetic mass around the head, which joins with the mass of the racket and launches forward.

As sporting launches go, this was one of the more prosaic. But Richard Lewis, the Lawn Tennis Association coach, is convinced. He said yesterday that although the benefits to the world's leading players would be marginal, he would recommend the racket at club level. 'It does work,' he concluded.

(Photograph omitted)