著者
蔭山 雅洋 鈴木 智晴 藤井 雅文 中本 浩揮 和田 智仁 前田 明
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.61, no.2, pp.517-535, 2016 (Released:2016-12-14)
参考文献数
37
被引用文献数
2 5

The purpose of this study was to clarify the profiles of lower limb and trunk motion during baseball pitching in relation to differences between the mound and the flat ground, and to determine the motion characteristics while pitching from the 2 locations.  The subjects were 12 baseball pitchers (age 18.6±2.5 yr, height 173.4±6.5 cm, weight 74.7±11.0 kg) who belonged to high school or university baseball teams. Three-dimensional positions of 36 reflective markers attached to each subject were tracked by an optical motion capture system (Mac3D System) with 12 cameras. The ground-reaction forces (GRF) of the pivot and stride legs during pitching were determined using 2 multicomponent force plates. Pitching motion was divided into two phases: phase 1 was defined as the period from when the knee of the stride leg reached maximal height (MKH: 0%time) until the point when the stride foot made contact with the ground (SFC: 100%time), while phase 2 was defined as the period from the SFC until the point when the ball was released (REL: 200%time). Ball velocity was measured using a radar gun.  The results were as follows: 1) The maximum and average ball velocities were significantly higher when pitching was performed from the mound than from the flat ground (p<0.05). 2) Hip/knee flexion angles and hip abduction/extension angular velocities on the pivot leg were significantly greater for mound pitching than for flat ground pitching, and the hip/knee extension angle and hip adduction/internal rotation/flexion angular velocities on the stride leg were significantly greater for the former (p<0.05). 3) The GRF of the stride leg was significantly greater for mound pitching than for flat ground pitching (p<0.01). 4) Upper torso and pelvis angle/angular velocities at SFC and the maximum pelvis, upper torso and trunk tilt angular velocities were significantly greater for mound pitching than for flat ground pitching (p<0.05).  The present results indicate that baseball pitchers show biomechanical differences in the kinematic and kinetic profiles of the trunk and lower limbs when pitching from the mound in comparison with the flat ground, and that high school or collegiate baseball pitchers can increase their pitched ball velocity by using the height of the mound.
著者
蔭山 雅洋 鈴木 智晴 岩本 峰明 中島 一 前田 明
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.60, no.2, pp.737-757, 2015 (Released:2015-12-18)
参考文献数
39

The purpose of the present study was to clarify the profiles of the lower limb and trunk motion during baseball pitching in relation to their differences between the wind-up and the set positions, and to determine how the ball pitching velocity can be increased in the set position. The subjects were 12 high school baseball pitchers (age: 16.4±0.5 yr, height: 173.7±4.8 cm, weight: 64.8±8.1 kg). Pitching was assessed using a three-dimensional motion system and 2 multicomponent force plates. It was found that 1) the maximum and average pitched ball velocities were significantly lower in the set position than in the wind-up position, 2) the maximum ground-reaction force of the pivot and stride legs and the impulse of pivot during the stride phase (from the time of maximal stride knee height to the time of maximal anterior push-off force) were significantly lower in the set position than in the wind-up position, and 3) the maximum upper torso/trunk twist angular velocity and the pelvis/upper torso angular velocity at moment of the stride foot contact were significantly lower in the set position than in the wind-up position. These results indicate that 1) the ball pitching velocity in the set position is lower than in the wind-up position. In addition, the factors associated with this lower ball velocity are suggested to be 2) decreased momentum of the pivot leg and 3) decreased rotation motion of the trunk during the arm acceleration phase.   Therefore, in order to increase ball pitching velocity in the set position, increasing the moment to the rear of the pivot leg during a short period and improvement of lower limb strength/power with the extension movement of the hip and knee joint may be important factors.
著者
鈴木 智晴 藤井 雅文 村上 光平 中本 浩揮 前田 明
出版者
一般社団法人 日本体育・スポーツ・健康学会
雑誌
体育学研究 (ISSN:04846710)
巻号頁・発行日
vol.64, no.1, pp.79-87, 2019-06-17 (Released:2019-06-25)
参考文献数
8
被引用文献数
2

One of the important roles of a baseball catcher is to check whether an opponent is trying to steal a base. This checking action must occur as part of other events: a quick throwing action (short operation time), a high ball speed (short duration of ball flight), and accurate tagging (the time from the fielder catching the ball to touching the opponent runner is short). In other words, in order for the catcher to check whether an opponent is trying to steal a base, it is necessary to shorten the time between catching the ball and when the fielder touches the opponent runner. However, the relationship between the time and the possibility of checking for an attempt to steal a base and the influence of each phase on the steal check rate have not been examined. The present study investigated the relationship between the time required to prevent a steal and the steal check rate of a baseball catcher using video recordings. The video recordings used for our analysis were videos of steal check successes and failures in exhibition and official university and amateur baseball games, with a focus on runners attempting to steal second base. We classified Motion Time as the period from catching the initial pitch to ball release, Ball Time as the period from ball release to ball arrival at second base, and Touch Time as the period from ball arrival at second base to the fielder touching the runner; the sum of these 3 phases was defined as All Time, and the sum of Motion Time and Ball Time was defined as Pop Time. We constructed 3 models in which the success or failure of the steal check was set as a target variable and each phase time as an explanatory variable, and performed logistic regression analysis on each model. As a result, we clarified that the baseball catcher could check for a steal if the All Time was less than 2.429 s, and there was a significant negative correlation between the steal check rate and All Time. In addition, among the three phases, Touch Time had the greatest effect on the steal check rate. Therefore, it was suggested that accurate throwing is the most important factor in preventing a steal to second base.
著者
蔭山 雅洋 鈴木 智晴 杉山 敬 和田 智仁 前田 明
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.60, no.1, pp.87-102, 2015 (Released:2015-06-13)
参考文献数
34
被引用文献数
4 3

The purpose of this study was to clarify the relationship between ball velocity and the mechanical power of the lower limbs during pitching motion in 30 collegiate baseball pitchers. 3-dimensional positions of 37 reflective markers attached to the subject were tracked by an optical motion capture system (Mac3D System) with 12 cameras. The ground-reaction forces (GRF) of the pivot and stride legs during pitching were determined using 2 multicomponent force plates. Pitching motion was assessed in terms of the joint torques, joint torque powers and work done by each of joint in the lower limbs using a three-dimensional motion system. The joint torques of the hip, knee, and ankle were calculated using inverse-dynamics computation of a musculoskeletal human model (nMotion musculous 1.51). Pitching motion was divided into 2 phases: phase 1 was defined as the time taken from the knee of the stride leg reaching maximal height (MKH, 0%time) to the stride foot making contact with the ground (SFC, 100%time), and phase 2 was defined as the time taken from SFC to the ball being released (REL, 200%time).  These studies revealed that the positive work resulting from hip abduction (r=0.401) and knee extension (r=0.355) of the pivot leg (Phase 1) was positively correlated with ball velocity (p<0.05). The positive work resulting from hip adduction (r=0.359) and knee extension (r=0.409) of the stride leg (Phase 2) was positively correlated with ball velocity (p<0.05). In addition, the pitched ball velocity was positively correlated with pivot hip abduction torque at 74–94%time, pivot hip internal rotation torque at 76–89%time, stride hip adduction torque at 96–114%time, stride hip adduction torque power at 108–114%time, stride knee extension torque at 101–131%time, stride knee extension angular velocities at 158–189%time, and stride knee extension torque power at 156–174%time (p<0.05).   These results indicate that a pitcher with high pitched ball velocity can generate hip abduction and knee extension power of the pivot leg, and that these are increased by hip abduction and hip internal rotation torque when moving the body forward before stride foot contact. In addition, it is suggested that high-ball-velocity pitchers can generate hip abduction and knee extension torque in order to stabilize the body just after stride foot contact, and that these are increased by the knee extension power for increasing trunk rotation and trunk twisting from the first half to the middle of the second phase.   Therefore, the present results indicate that pitchers with a higher ball velocity can generate greater mechanical power of the lower limbs for increasing the energy of trunk rotation and the arm.
著者
蔭山 雅洋 鈴木 智晴 杉山 敬 和田 智仁 前田 明
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.14061, (Released:2015-03-17)
参考文献数
35
被引用文献数
5 3

The purpose of this study was to clarify the relationship between ball velocity and the mechanical power of the lower limbs during pitching motion in 30 collegiate baseball pitchers. Three-dimensional positions of 37 reflective markers attached to the subject were tracked by an optical motion capture system (Mac3D System) with 12 cameras. The ground-reaction forces (GRF) of the pivot and stride legs during pitching were determined using two multicomponent force plates. Pitching motion was assessed in terms of the joint torques, joint torque powers and work done by each of joint in the lower limbs using a three-dimensional motion system. The joint torques of the hip, knee, and ankle were calculated using inverse-dynamics computation of a musculoskeletal human model (nMotion musculous 1.51). Pitching motion was divided into two phases: phase 1 was defined as the time taken from the knee of the stride leg reaching maximal height (MKH; 0%time) to the stride foot making contact with the ground (SFC; 100%time), and phase 2 was defined as the time taken from SFC to the ball being released (REL; 200%time).  These studies revealed that the positive work resulting from hip abduction (r=0.401) and knee extension (r=0.355) of the pivot leg (Phase 1) was positively correlated with ball velocity (p<0.05). The positive work resulting from hip adduction (r=0.359) and knee extension (r=0.409) of the stride leg (Phase 2) was positively correlated with ball velocity (p<0.05). In addition, the pitched ball velocity was positively correlated with pivot hip abduction torque at 74-94%time, pivot hip internal rotation torque at 76-89%time, stride hip adduction torque at 96-114%time, stride hip adduction torque power at 108-114%time, stride knee extension torque at 101-131%time, stride knee extension angular velocities at 158-189%time, and stride knee extension torque power at 156-174%time (p<0.05).  These results indicate that a pitcher with high pitched ball velocity can generate hip abduction and knee extension power of the pivot leg, and that these are increased by hip abduction and hip internal rotation torque when moving the body forward before stride foot contact. In addition, it is suggested that high-ball-velocity pitchers can generate hip abduction and knee extension torque in order to stabilize the body just after stride foot contact, and that these are increased by the knee extension power for increasing trunk rotation and trunk twisting from the first half to the middle of the second phase.  Therefore, the present results indicate that pitchers with a higher ball velocity can generate greater mechanical power of the lower limbs for increasing the energy of trunk rotation and the arm.
著者
鈴木 智晴 藤井 雅文 村上 光平 中本 浩揮 前田 明
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
2019

One of the important roles of a baseball catcher is to check whether an opponent is trying to steal a base. This checking action must occur as part of other events: a quick throwing action (short operation time), a high ball speed (short duration of ball flight), and accurate tagging (the time from the fielder catching the ball to touching the opponent runner is short). In other words, in order for the catcher to check whether an opponent is trying to steal a base, it is necessary to shorten the time between catching the ball and when the fielder touches the opponent runner. However, the relationship between the time and the possibility of checking for an attempt to steal a base and the influence of each phase on the steal check rate have not been examined. The present study investigated the relationship between the time required to prevent a steal and the steal check rate of a baseball catcher using video recordings. The video recordings used for our analysis were videos of steal check successes and failures in exhibition and official university and amateur baseball games, with a focus on runners attempting to steal second base. We classified Motion Time as the period from catching the initial pitch to ball release, Ball Time as the period from ball release to ball arrival at second base, and Touch Time as the period from ball arrival at second base to the fielder touching the runner; the sum of these 3 phases was defined as All Time, and the sum of Motion Time and Ball Time was defined as Pop Time. We constructed 3 models in which the success or failure of the steal check was set as a target variable and each phase time as an explanatory variable, and performed logistic regression analysis on each model. As a result, we clarified that the baseball catcher could check for a steal if the All Time was less than 2.429 s, and there was a significant negative correlation between the steal check rate and All Time. In addition, among the three phases, Touch Time had the greatest effect on the steal check rate. Therefore, it was suggested that accurate throwing is the most important factor in preventing a steal to second base.