A Mechanical Study on Tennis Racquets to Investigate Design Factors that Contribute to Reduced Stress and Improved Vibrational Dampening

Abstract There are a multitude of factors that will affect the mechanical performance and stress transfer to a tennis player's upper extremities. Variations in frame design, materials, string tensioning, ball stiffness, impact locations, and player technique are just some of the potential variables that can result in a significant increase or decrease of stress transfer and vibration from the racquet to the player. To better understand the significant contributing design factors that influence shock and vibration transmission to the racquet handle upon impact, such testing was conducted in a standardized and repeatable manner to evaluate and compare the shock and vibration patterns for multiple frame designs from a variety of high performing tennis racquets. Multiple racquet frame designs from six different manufacturers were mechanically tested in an ISO17025 certified third-party independent test facility by qualified mechanical and biomechanical engineers. A consistent mass drop technique was employed to provide controlled impact to the center of the head of each mounted racquet. The impact load and duration were plotted and a Fourier Transform Analysis was conducted on each data file. The results of this study showed statisticall y significant reductions in vibrational dampening time and lower vibrational amplitudes following the initial impact shock for the triple core designs. This evaluation provided consistent baseline comparisons for different handle designs in a manner that demonstrated multi-layered cores of the racquet handle performed better than hollow designs with respect to vibration and force attenuation.