|
Sliding to return a shot is a common tennis practice on clay courts, but lately players have started using it on grass and hard courts as well. Scientists say it is faster than running and allows athletes to change direction more quickly. "The speed of the game has increased a lot because the players are serving faster than years before," said Daniel Ura, a researcher in the University of Sheffield's Department of Mechanical Engineering. "It could be because of the materials of the rackets, or could be the strings as well. But I think it's a necessity of the players to reach the ball faster." So far, only a few top players have mastered the technique off clay. For effective slides, the shoes must perfectly match the court's surface, and this is where the science comes in handy. "I think it will become more like a Formula 1 race probably," Ura said, with the right shoe depending on the weather or the surface conditions. Looking for the best match between shoe and surface, researchers at the University of Sheffield have built a special mechanical rig that can measure the shoe traction. "In order to do that," said Matt Carre, an instructor in the mechanical engineering department, "we need to understand a number of parameters, including how the shoe changes, how the properties of the shoe affect that interaction, how the properties of the tennis courts affect that, and also other factors like temperature" and how the players slide or move around the court. | 
