Tennis racket and ball responses during impact under clamped and freestanding conditions.

Abstract Selected responses of a tennis racket and ball during the impact phase were investigated in an attempt to establish the influence of grip firmness on ball velocity after impact. Two extreme conditions of grip firmness were considered: (a) when the grip of the racket was firmly clamped to a rigid metal support frame and (b) when the racket was allowed to stand freely on its butt with no other means of support. The study was conducted in two parts: 1. Three multiple-exposure photographs were taken of ball impacts on a variety of rackets with different constructions, flexibilities, string types, and string tensions under the two conditions of grip firmness. Measurements were taken from enlargements of these photographs in order to calculate the horizontal component of post- to pre-impact ball velocity. 2. A high-speed cinematographic analysis was conducted of one ball-racket impact under both conditions of grip firmness. It was found that the magnitude of the impulse applied by the racket to the bal...