Biomechanical Determinants And Their Relationship To Effectiveness Index Of Performing Backhand Stroke In Tennis As A Basis To Plan Specific Training Methods

Abstract

The aim of this case study is to investigate kinematic determinants of ball, racket, and body center of gravity during backhand stroke in tennis, and their relationship to ball's launch and exit speed. It also examines angular kinematic determinants of body (body angles) during moments of performance and their relationship to ball's launch and exit speed. This study investigated kinematic determinants of body and striking arm during performance moments and their relationship to speed of ball release and release. The study sample consisted of a junior-level player (age 18, height 1.82 m, weight 75 kg, 10 years of training experience). Backhand stroke in tennis was filmed and analyzed using three high-speed GoPro Hero 6 cameras set to frequencies of 120 fps and 60 fps. Cameras (1) and (2) were set to 60 fps to study details of body connections, while camera (3) was set to 120 fps to study details of ball and release indicators from the racket. Three-dimensional analysis was performed using Skillspector software to extract kinematic variables of body, ball release indicators, kinematics of torso and striking arm connections, and center of gravity. Key findings height of ball at the moment of impact is affected by increasing ball's launch and exit velocity. The ball's launch velocity is affected by rate of the racket's basic horizontal acceleration distance. Increasing the racket's vertical acceleration distance leads to an increase in the ball's exit angle. Increasing the racket's net acceleration distance leads to an increase in the ball's exit angle, noting that the racket's net acceleration distance is affected by rate of the racket's basic vertical acceleration distance. The ball's launch and exit velocity are affected by angle of right ankle during initial basic acceleration of the racket and angle of right knee joint during the ball's launch and exit from the racket.