野球の投球におけるボールリリース時の力学的変数が到達位置に及ぼす影響

（シミュレーション研究）

抄録

The purpose of this study was to verify the precision of different simulation methods to extrapolate vertical pitch location with the use of some dynamic parameters at ball release measured by TrackMan, and to determine dynamic parameters to predict pitch location. Ball trajectory was calculated by the equation of motion with three different numerical analysis methods (Euler, Runge-Kutta, Dormand Prince) and the vertical pitch location was compared with the measured values. The total number of pitches was 137 pitches. Dormand Prince method showed the smallest errors (5.8 ± 1.4 cm) compared with Euler (6.8 ± 1.4 cm) and Runge-Kutta (6.7 ± 1.4 cm) methods, indicating Dormand Prince was the highest precision method to extrapolate pitch location, but all methods could extrapolate it below the size of ball. Simulation with Dormand Prince method and multiple regression analysis revealed that elevation pitching angle and ball velocity more predicted vertical pitch location rather than other parameters. Furthermore, regression equation structured by these parameters could predict the pitch location with error by less than 10.0 cm (9.5 cm). These results indicate that the elevation pitching angle and ball velocity, i.e. velocity vector of ball, affected the determination of pitching location.