The centre of percussion of tennis rackets: a concept of limited applicability

The concept of the centre of percussion of rigid bodies, and that of its conjugate point, the locus of restraint, is considered to be an important feature in the design and construction of tennis rackets. Using theoretical analysis, computer simulations, and experimental observations, the present investigation provides convincing evidence that a stationary locus of restraint does not exist in tennis rackets because of the torque and forces imparted on the racket handle by the player's hand during impact. It is suggested that, instead of being restricted to a stationary locus of restraint, the concept be extended to a migratory locus of restraint. This may enable racket designers to optimize design parameters in such a way as to minimize hand reaction forces during impact.