大学野球投手のピッチングにおける投球数がパフォーマンスおよび生理心理機能・体力・動作に及ぼす影響

抄録

This study aimed to examine the effects of college baseball pitching on movement, performance, physical strength, and physiological and psychological functions of pitchers. The participants were 10 right-handed male pitchers from the University baseball team. The number of pitches were 15 per inning and 135 per nine innings. Ball speed and accuracy were measured for each pitching. The grip strength, back muscle strength, and standing long jump were measured before and after all pitches. Blood lactate levels were measured before pitching, at the end of the 5th and 7th innings, and at 3rd, 6th, and 9th minutes after pitching. The participant’s heart rate and subjective exercise intensity were measured at the beginning and end of each inning using the Borg scale measurement. Five high-speed cameras were used to capture the pitching motions. The displacement of the center of gravity, lower and upper limb joint angles, and the speed of each segment were calculated. The baseball speed and accuracy did not change with the increased number of pitches. However, the grip strength decreased. Although blood lactate and heart rate were not altered, subjective exercise intensity was increased. The lower limb kinematics remained unchanged; however, elbow height was reduced in the upper limb. These results suggest that highly competitive pitchers experience subjective fatigue with the increased number of pitches, however, they maintain pitch performance, speed, and accuracy without altering whole-body physiology and lower-body function and form.