The effectiveness of grip bands in reducing racquet vibration transfer and slipping.

The effectiveness of cushion grip bands in reducing impact shock and vibration transfer, and slipping in tennis racquets has been investigated. The results also apply, in principle, to badminton and squash racquets, and to golf clubs. An artificial arm (manusimulator) replicating the structure and all the important properties of the real human arm (shoulder, upper- and forearm, hand, soft tissue- and muscle simulators, etc.) was used together with a standard tennis racquet for the investigation. Laser beams were employed for precision adjustment of the spatial racquet position and the ball impact location. The impact velocity was standardized at 20 m.s-1 +/- 1.2%, while the impact point was located 32.5 +/- 2 mm distal to the sweet spot (the nodal point of the fundamental transverse vibration mode) on the racquet long axis. The grip circumference for the 26 different grip bands tested was controlled at 116 +/- 1 mm (grip size 5), and the adjustable manusimulator grip pressure was kept at preset values. Impact shock and post-impact racquet vibrations were determined by manusimulator-accelerometry, while slipping resistance was measured by friction methods. The major finding was that cushion grip bands do statistically significant (at P = 0.05) reduce impact shock and vibration transfer in tennis racquets, albeit to varying degrees depending on the brand. At present, there is no clear indication whether these reductions are, in fact, biologically relevant. Very large differences were found to exist between the various grip band types as regards the reduction of slipping.