KINEMATIC ANALYSIS ON THE PUNT KICK IN FOOTBALL GOALKEEPER

The present study aimed to investigate punt kicks by football goalkeepers on the basis of differences in the effort of the kick. Twelve experienced goalkeepers participated in the study. The participants were made aware that for the maximum distance trial (the 100% trial), they should send the ball as far as possible, and for the 80% and 60% trials they should have a more controlled approach. Punt kicks were divided into three phases: the phase of release of the ball from the left hand (BR), the phase of pivot foot ground-contact (LFC), and the phase of the ball impact (IMP). Right hip and knee joint angles were calculated. In comparison to lower intensity punt kicks, the higher effort punt kicks involved increasing the hip joint extension angle for the right foot during the backswing and lowering the knee joint angle of the right leg at the start of the forward swing, thereby producing forward swing velocity for the right foot

ADJUSTMENT MOVEMENT TO BASEBALLS TOSSED AT DIFFERENT VELOCITIES IN BASEBALL BATTING. －FOCUS ON A SHIFT IN THE CENTRE OF GRAVITY－

The purpose of this study was to compare shifts in the centre of gravity (CG) when balls were tossed at different velocities, in order to obtain data for coaching purposes. The subjects were 10 experienced university baseball players. The subject batted basic toss up ball toward the centre field, both fastballs and slowballs. Data were collected using 2 high-speed cameras (NAC Inc., Japan). The movement timing and velocity of the center of gravity were computed. Batting motion was divided into three phases. The mean times in the 1st phase and 3rd phase were approximately the same for both fast and slow balls, but both the time and distance by which the CG moved in the 2nd phase were significantly greater for slow balls than for fast balls

INFLUENCE OF THE BALL SPEED ON THE DISPLACEMENT OF THE CENTER OF GRAVITY DURING BASEBALL BATTING MOTION

The purpose of this study was to investigate the modification in batting motion with different pitching speeds focusing on differences in batting technical level. The subjects were 10 experienced university baseball player. The subjects batted toward the center field, both fastballs and slowballs, aimed near the center of the strike zone from a pitching machine. Data were collected using a three dimensional automatic motion analysis system (Vicon MX). The displacement of the center of gravity(CG) were computed. Significant differences were seen due to difference in pitching speed in unskilled player. Conversely, in skilled player, no significant difference was found in the movement of CG due to the difference in pitching speed. It was revealed that it was not preferable for movement of the CG to fluctuate by difference in pitching speeds