Medição e análise das vibrações transmitidas ao antebraço de uma jogadora de ténis: um estudo de caso

• Author(s): Raquel Francisca da Silva Mateus
• Date: 2017
• Origin: Repositório Aberto da Universidade do Porto
• Subject(s): Outras ciências sociais; Other social sciences
• Document Type: Master thesis
• Language: Portuguese

Description

With the progressive improvement and diversity of tennis rackets, it is fundamental for a player to know the most appropriate model, due to game style and anthropometric characteristics. Thus, owing to lack of literature related to this subject, the aim of this study was focused on the recognition of the possible proportion between the increase of stiffness of the racket frame and the increase of the probability of musculoskeletal injury. After an initial selection of three different rackets used by the player throughout her career, the data was projected by the application of two triaxial accelerometers, placed in the player's wrist and in the racket "throat" area, in order to know the accelerations generated in each of them, after the impact of a tennis ball, previously projected by a pneumatic ball cannon. The results show a higher incidence of injury the longer the time and level of play, showing also that the accelerations generated at the first vibration frequency, inferior to 200Hz, are the most damaging, independently of the racket studied. In addition, the stiffest racquet (Babolat Pure Drive GT 2012) provides greater wrist and racket accelerations, while the most flexible model (Tecnifibre Rebound Pro (1st model)) has a greater reduction of accelerations between the racket and the wrist, at the first frequency of vibration, but greater accelerations on the wrist in comparison to the other models. These results highlight the need to explore stiffness as one of the most potentiating factors in tennis player forearm injuries. In order to better understand their effects on surrounding muscles, the future development of studies should involve muscle electromyography, different sizes of the racket's grip and resulting effects of the different impact areas on it.