Abstract des Autors

In tennis groundstrokes, the speed of the racket head depends on the rotational velocities of the upper limb segments and the corresponding instantaneous position of the racket. The method of holding the racket may influence these factors. Six high-performance tennis players who preferred the eastern method of holding the racket and a further 6 who preferred the western method were filmed. The displacement histories of 16 selected landmarks were calculated using the direct linear transformation approach and were used to calculate the contribution that the three-dimensional individual segment rotations for the upper limb made to racket head velocity. Horizontal flexion/abduction and internal rotation of the upper arm, in addition to linear velocity of the shoulder, were the primary contributors to racket head speed at impact, regardless of grip. Significant variations, however, were recorded for the contribution of the hand segment to racket head speed for the different grip positions. Verf.-Referat