The Influence Of Friction Properties Of Shoe Upper Materials On Kicking Velocity In Soccer

Abstract

INTRODUCTION Kicking is the most typical sport specific technique in soccer and has received considerable attention in biomechanical research [1]. Fast kicking may make the difference to score in a game and thus kicking velocity is to be seen as a decisive factor for success in soccer. It was shown that different soccer shoe models evoke different ball velocities during full instep kicking [2,3]. The underlying mechanisms of differing ball velocities in different shoes have not been fully explored yet. Obviously, the collision mechanics during the contact period of foot/shoe and ball determine the quality of the kick with respect to accuracy and velocity. However, the impact during the collision phase cannot be described solely according to Newton’s laws as these describe mechanics for purely elastic impacts. In kicking, during the collision phase, displacement (≈ 26 cm) of the ball takes place [4]. Therefore, the propulsion procedure has to be regarded as a mixture of a throwing-like and an impact-like situation. Friction properties of shoe upper materials potentially have an influence on ball velocity during kicking, especially during kicks in which the core impact is located off-centered. This naturally occurs in games and during biomechanical studies. Therefore, the purpose of this study was to quantify the influence of different shoe upper friction properties on ball velocity during full instep kicking.