Abstract

The present study is concerned with the problem of the most desirable grip tightness during and after the impact phase of the tennis stroke. Moreover, impact forces and duration for different ball velocities are also investigated. Three series of experiments were conducted in order to abtain information on impact forces and durations, responses of the racket to impacts for loose and tight grips, and the magnitudes of the vibrations of the racket transferred to the hand in actual strokes. The experimental results were found to be in accordan ce with thepredictions of a mathematical model of the system rackethand. A simpler model, which neglects bending and possible translations of the rakket, turns out to be inadequate for the present purpose. It is found that a tight grip increases both the impulse impared on the ball and hence the power of the stroke, and the vibrational shocks which must be absorbed by the hand. The contrary holds true for a loose grip. An investigation on a top-class player revealed that he uses a tight grip in all his strokes. The possibility of a connection between grip tightness during and after the impact phase and the occurrence of the well-known tennis elbow is also discussed. Avoidance of the impact recoil was found to be impossible. Verf.-Referat