著者

森下 義隆 矢内 利政

出版者

一般社団法人 日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.63, no.1, pp.237-250, 2018-06-10 (Released:2018-06-20)

参考文献数

27

被引用文献数

2 1

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The purpose of this study was to examine within-subject differences in bat-swing trajectory between intentional hitting towards the same field and towards the opposite field. 19 industrial league baseball batters and 16 collegiate baseball batters performed same-field hitting (SH) and opposite-field hitting (OH). The movement of the bat during the swing was recorded with two high-speed cameras (1000 fps) for 3D analysis. At the instant of ball impact, the striking surface of the bat faced towards the same field in SH and towards the opposite field in OH. The bat-head trajectory immediately before impact was directed obliquely upward in SH, whereas it was directed obliquely downward in OH. Throughout the swing, the projection angle of the bat on the vertical plane was greater in OH than in SH, and the ratio of the translational component of the bat-head speed to the resultant bat-head speed was significantly greater in OH than in SH. These results suggest that the characteristics of the bat swing in OH provide a suitable impact condition to drive the ball towards the opposite field, as evidence has demonstrated that (1) a batted ball is likely to travel towards the opposite field when the lower half of the ball is hit by a vertically inclined bat, and (2) the striking surface of the bat is unlikely to turn to face towards the same field when the contribution to the resultant bat-head speed is generated more by the translational component of the bathead speed than by the rotational component.

著者

森下 義隆 矢内 利政

出版者

一般社団法人 日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

pp.17004, (Released:2018-02-15)

参考文献数

27

被引用文献数

2 1

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The purpose of this study was to examine within-subject differences in bat-swing trajectory between intentional hitting towards the same field and towards the opposite field. 19 industrial league baseball batters and 16 collegiate baseball batters performed same-field hitting (SH) and opposite-field hitting (OH). The movement of the bat during the swing was recorded with two high-speed cameras (1000 fps) for 3D analysis. At the instant of ball impact, the striking surface of the bat faced towards the same field in SH and towards the opposite field in OH. The bat-head trajectory immediately before impact was directed obliquely upward in SH, whereas it was directed obliquely downward in OH. Throughout the swing, the projection angle of the bat on the vertical plane was greater in OH than in SH, and the ratio of the translational component of the bat-head speed to the resultant bat-head speed was significantly greater in OH than in SH. These results suggest that the characteristics of the bat swing in OH provide a suitable impact condition to drive the ball towards the opposite field, as evidence has demonstrated that (1) a batted ball is likely to travel towards the opposite field when the lower half of the ball is hit by a vertically inclined bat, and (2) the striking surface of the bat is unlikely to turn to face towards the same field when the contribution to the resultant bat-head speed is generated more by the translational component of the bathead speed than by the rotational component.

著者

森下 義隆 村田 宗紀

出版者

独立行政法人 日本スポーツ振興センター国立スポーツ科学センター

雑誌

Journal of High Performance Sport (ISSN:24347299)

巻号頁・発行日

vol.6, pp.88-100, 2020 (Released:2020-10-10)

参考文献数

20

被引用文献数

1

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In this study, we investigated the kinematic characteristics of various pitch types thrown by skilled softball pitchers. Nine female softball pitchers from the national Japanese softball team were requested to throw various pitch types that are used in competition and practice using the windmill style, while a three-dimensional motion capture system consisting of 20 infrared cameras (500 Hz) recorded reflective markers attached to the ball. The kinematic characteristics, such as the ball speed, spin rate, and direction of spin axis (angular velocity vector) were calculated from the measured coordinate values. The types of pitches (fastball, riseball, drop, and changeup) thrown by more than 5 pitchers were analyzed. The spin axes of all the analyzed trials were mostly oriented in the direction of the ball and upwards. The average ball speed of the fastball pitched by all pitchers had the highest, and in the case of the right-handed pitcher, the displacement of flight trajectory on the home plate changed by approximately 0.17 m downward and 0.06 m toward the left-handed batter under the influence of the lift force, as compared to that of the balls that were projected without rotation. Furthermore, when the flight trajectories of other pitch types were compared with that of fastball, the riseball, drop, and changeup types were shown to change in the upward, downward, and upper left directions, respectively. Our findings can be used as a guide to develop new pitch types or improve those that are currently employed in the game.

著者

神事 努 森下 義隆 平山 大作

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 : 日本バイオメカニクス学会機関誌 (ISSN:13431706)

巻号頁・発行日

vol.16, no.1, pp.41-46, 2012

著者

中島 大貴 森下 義隆 八木 賢太郎 桜井 伸二

出版者

日本バイオメカニクス学会

雑誌

バイオメカニクス研究 (ISSN:13431706)

巻号頁・発行日

vol.24, pp.8-18, 2020 (Released:2020-07-06)

参考文献数

23

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In baseball, the flight distance of batted balls is influenced by not only the batted ball velocity but also the spin. Previous studies reported that balls batted toward the opposite field (right field for the right-handed batter) had greater side spin and curved horizontally. If batters could impart less side spin to the ball, flight distance would be expected to increase because the ball would travel more linearly. The purpose of this study was to investigate how the spin of a batted ball is affected by the vertical bat angle at impact. A pitching machine was used to launch balls toward a fixed bat. The bat was positioned at six different angles under two conditions; the bat's long axis was adjusted horizontally and the bat head was declined 40° lower than the bat grip. The batted ball spins resulting from the batted ball angles were compared between the conditions. There were significant correlations between the horizontal batted ball angle and the side spin of the batted balls in both conditions. There was no significant difference between the slopes of the regression lines for the conditions. In brief, balls batted toward the same direction had similar spin regardless of the conditions. Therefore, it is suggested that the batters should not attempt to control batted ball spin, and increasing their bat swing speed would be still the most important key factor to hit balls long distances toward the various directions.

著者

森下 義隆

出版者

独立行政法人日本スポーツ振興センター国立スポーツ科学センター

雑誌

若手研究(B)

巻号頁・発行日

2017-04-01

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本研究は、近年、野球現場において多くの選手が取り組んでいる「増量」に着目し、打者の体重が打撃パフォーマンスに及ぼす影響について検討した。その結果、①即時的な増量は通常の打撃よりも全身の回転運動の勢い(角運動量)を増大できるものの、それをバットに伝達することができず、スイング速度を低下させてしまうことが示唆された。また、②体重そのものではなく除脂肪量(筋量)を増加させることがスイング速度の向上に寄与することが明らかとなった。以上のことから、打者の競技パフォーマンスの向上を目的に増量を行う場合、脂肪量ではなく除脂肪量によって体重が増加するように食事やトレーニングを調整することの重要性が示された。

著者

森下 義隆 勝亦 陽一 神事 努

出版者

一般社団法人 日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.64, no.2, pp.463-474, 2019-12-16 (Released:2019-12-20)

参考文献数

21

被引用文献数

2

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The purpose of the present study was to clarify the influence of swing parameters by changing the hitting point in space in baseball batting. Twenty-eight skilled baseball players (12 professional and 16 universitylevel) participated. The participants were instructed to hit a ball that was tossed from 5 m away in the direction of the pitching mound. The balls were tossed to various locations with reference to the home plate. The participants were required to hit the balls in a specific direction according to the tossed course, i.e., a ball tossed to the inside of a home plate was stroked toward the same-field direction and one tossed outside of the home plate was stroked toward the opposite-field direction. The motions of the ball and bat during these attempts were recorded using a motion capture system operating at 500 Hz. The 3D coordinates of the ball center (hitting point) and the swing parameters included the speed of the head of the bat (bat-head speed) and the angle of the swing from a horizontal line (swing angle) measured immediately before ball impact and the time from the start of the swing to ball impact (swing time). These parameters were calculated in each trial. Analysis of a total of 644 trials revealed that the bathead speed tended to increase as the hitting point moved inside, forward, and low. Furthermore, the swing angle and swing time tended to increase as the hitting point moved inside, forward, and high. Stepwise multiple regression analysis demonstrated that the bat-head speed and swing angle were independently associated with (in the following order) the distance in the pitcher’s direction, the hitting height, and the inside-outside direction course (R2=.360 and R2=.589, respectively). These results suggest that the timing of swing initiation and bat acceleration during a swing motion are the main factors changing the swing parameters, and that in order to sharp hit a ball, it is important to impact the ball with the hitting point as close to the pitcher as possible.

著者

森下 義隆

出版者

早稲田大学

巻号頁・発行日

pp.1-135, 2015

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早大学位記番号:新7097

著者

森下 義隆

出版者

早稲田大学

巻号頁・発行日

2016

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終了ページ : 135

著者

森下 義隆 勝亦 陽一 神事 努

出版者

一般社団法人 日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

pp.18058, (Released:2019-07-05)

参考文献数

21

被引用文献数

2

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The purpose of the present study was to clarify the influence of swing parameters by changing the hitting point in space in baseball batting. Twenty-eight skilled baseball players (12 professional and 16 universitylevel) participated. The participants were instructed to hit a ball that was tossed from 5 m away in the direction of the pitching mound. The balls were tossed to various locations with reference to the home plate. The participants were required to hit the balls in a specific direction according to the tossed course, i.e., a ball tossed to the inside of a home plate was stroked toward the same-field direction and one tossed outside of the home plate was stroked toward the opposite-field direction. The motions of the ball and bat during these attempts were recorded using a motion capture system operating at 500 Hz. The 3D coordinates of the ball center (hitting point) and the swing parameters included the speed of the head of the bat (bat-head speed) and the angle of the swing from a horizontal line (swing angle) measured immediately before ball impact and the time from the start of the swing to ball impact (swing time). These parameters were calculated in each trial. Analysis of a total of 644 trials revealed that the bathead speed tended to increase as the hitting point moved inside, forward, and low. Furthermore, the swing angle and swing time tended to increase as the hitting point moved inside, forward, and high. Stepwise multiple regression analysis demonstrated that the bat-head speed and swing angle were independently associated with (in the following order) the distance in the pitcher’s direction, the hitting height, and the inside-outside direction course (R2=.360 and R2=.589, respectively). These results suggest that the timing of swing initiation and bat acceleration during a swing motion are the main factors changing the swing parameters, and that in order to sharp hit a ball, it is important to impact the ball with the hitting point as close to the pitcher as possible.