Tennis footwork is the basis of any shot ability. In the modern game, quick footwork is needed as the ball is traveling faster. In the past footwork was everything, because it was needed to hit through the ball, with standard size racquets. The newer racquets have softened the need to square up to the ball, and have produced tennis elbow and lots of injuries due to arm generated shots. Bigger racquets, seem to breed less concentration on the ball, and shorter swings. I am not referring to the Pro game, the pros's use smaller racquets, and of course have great footwork. As a experiment, try using a standard size racquet, like a wood racquet, or old T-2000 connors used. Actually it is a good teaching tool for footwork, as you have to pay attention, and hit through the ball, with the right body position and balance. The ball machine is a good tool to hone strokes, and work on proper footwork.