THREE DIMENSIONAL KINEMATICS OF THE DIRECT FREE KICK IN SOCCER WHEN OPPOSED BY A DEFENSIVE WALL

Abstract

INTRODUCTION According to the tules of play, the game of soccer is divided into two 45 minute halves. During most of this time, play is continuous. However, when play is stopped, teams have time to strategically position themselves both offensively and defensively. Even though these stoppages account for a relatively small portion of the total "running time," set plays (corner kicks, throw-ins, and free kicks) from restarts have been reported to account for forty percent of the goals scored (Hughes, 1973). Thus, set plays are critical to the outcomes of soccer games. Various studies of the soccer kicking motion have been conducted. Some of these studies have involved an analysis of the forces and moments of the lower extremity Osokawa and Lees, 1988; Luhtanen, 1988; Zernicke and Roberts, 1978). Others have related mechanical efficiency (Asami et al., 1976), isokinetic leg strength (DeProft et al., 1988; Narici et aI., 1988; Too and Hoshizaki, 1984), and electromyographical activity of leg muscles to the soccer kick. However, no studies of the kinematics of the free kick under game-like conditions were found. Thus, the purpose of this study was to investigate selected kinematic parameters of the kicking techniques used in taking a free kick when opposed by a defensive wall.