Abstract
This study aimed to clarify the characteristics of throwing motion to second base of the professional baseball catcher who has been selected for the Japan national team and has previously recorded the highest stolen base prevention rate in a season. Although the player’s long throw distance （arm strength） was not outstanding as a professional baseball player, his quick movements had been described as leading to a high base-stealing prevention rate. We compared the throwing motion of this catcher to three other professional baseball catchers. An optical three-dimensional motion analysis system and a force plate were used to measure the throwing to second base. The throwing motions were divided into three phases. Duration of each phase, ball speed, and kinematics were then analyzed. The results showed that the catcher selected for the national team took the shortest time from the catching phase to the release phase. In particular, the time required from the time of catching the ball to the time when the pivot foot contacted the ground was shorter than those of the other three catchers. In addition, the catcher selected for the national team showed the highest value of velocity of center of gravity（ CoG） at the time of catching. These results suggest that the catcher selected for the Japan national team shortened the time from the time of catching the ball to the time when their pivot foot contacted the ground by increasing the velocity of CoG even before catching the ball, and that they made a quicker throwing motion to second base by shortening the motion time.
