著者

平山 大作 藤井 範久 小池 関也 阿江 通良

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.59, no.2, pp.225-232, 2010 (Released:2010-05-27)

参考文献数

24

被引用文献数

2 3

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The purpose of this study was to investigate the changes on mechanical work of the lower limb joints during baseball pitching in a simulated game. One male college baseball pitcher threw 15 pitches in an inning for 9 innings (135 pitches) in an indoor pitcher's mound with two force platforms. Rest time between innings was 6 minutes. Three-dimensional positions of 47 reflective markers attached to subject were tracked by an optical motion capture system (Vicon Motion System 612, Vicon Motion Systems) with eight cameras (250Hz). For subject 75 fastball pitches (1st, 3rd, 5th, 7th, and 9th innings) were chosen for analysis.As the main results, the hip joint extension absolute and negative work of the stride leg decreased with increasing the number of pitches. The ankle joint extension absolute and negative work of the stride leg increased with increasing the number of pitches. These results suggest that the hip joint extension torque of the stride leg was needed to maintain for higher performance in baseball pitching.

著者

平山 大作 藤井 範久 阿江 通良 小池 関也

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.19, pp.91-102, 2008 (Released:2017-02-15)

参考文献数

19

被引用文献数

6 4

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本研究は, 大学野球投手を対象とし, 投球数の増加にともなうキネティクスの変化について検討することを目的とした. 実験試技は, 2台のフォースプラットフォームを埋設した簡易マウンドからストレートを投球するものであった. 被験者には, 10秒間隔で15球投げることを1イニングとし, イニング間に6分の休息をはさみながら9イニング, 計135球の投球を行わせた. 投球数とそれぞれのパラメータから単回帰分析を行い, 回帰係数の有意性について検定を行った (p<0.05). その結果, 投球数の増加にともない, ①踏込脚の股関節伸展の正仕事, 負仕事, 絶対仕事が減少する傾向がみられた. ②投球腕の肩関節内旋の正仕事が減少する傾向がみられた. ③投球腕への関節力による力学的エネルギーの流れの減少がみられた. ④投球腕の肩関節水平内転の正仕事および絶対仕事が増加する傾向がみられた. 以上のことから, 踏込脚の股関節伸展の仕事の減少は, 下肢のトレーニングの重要性を示唆するものであり, 投球腕の肩関節水平内転の仕事の増加は, “上肢動作に頼った投球動作” を示すものであると考えられる.

著者

川村 卓 小池 関也 阿江 数通

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.37-48, 2019-06-17 (Released:2019-06-25)

参考文献数

22

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This study examined the flow of energy in the right and left upper limbs of skilled baseball batters during the forward swing motion at different bat head speeds to obtain basic insights that would be useful for batting coaching. The subjects were 23 college baseball outfielders in university teams. The subjects were instructed to hit a ball toward the pitcher from a tee set at a mid-height position. Measurements were taken using 47 points on each subject’s body and 6 points on the bat for a total of 53 points, onto which reflective markers were attached. The 3D coordinates of each marker were measured using a 3D optical motion capture device (Vicon Motion Systems’ VICONMX, 12 cameras, 250 Hz). The variables in the kinetics of each hand were measured using a force detection sensor bat (1000 Hz). The subjects were separated into a faster group of 36.8±0.8 m/s and a slower group of 34.7±1.1 m/s for analysis. In terms of energy transmission, the data revealed that the faster group, in addition to showing additional torque on the knob side shoulder joints, were able to transmit more mechanical energy from the knob side shoulder joints to the end of the upper limbs than the slower group, and that this might be related to an efficient bat head speed. In addition, the faster group showed an increased positive torque power, and transmitted greater mechanical energy to the bat from the hand region. In other words, to prevent mechanical energy from being absorbed while adjusting the bat trajectory near the time of impact, skilled bat control involving movement of the hand joints appeared to determine the bat head speed.

著者

阿江 数通 小池 関也 藤井 範久 阿江 通良 川村 卓 金堀 哲也

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.62, no.2, pp.559-574, 2017 (Released:2017-12-19)

参考文献数

46

被引用文献数

1

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The purpose of this study was to compare the kinematic characteristics of the upper body between baseball tee batting and pitched ball batting in order to gain basic knowledge for improvement of batting skill. Ten male collegiate baseball players (age: 20.7±1.1 yr; height: 1.75±0.05 m; body mass: 76.3±7.1 kg; athletic career: 12.7±2.7 yr) participated. They performed 2 kinds of batting: tee batting (TB) and machine-pitch batting (MB) using a pitching machine (approximate ball speed 33.3 m/s), which were set at middle ball height for the strike zone. Three-dimensional coordinate data were acquired with a motion capture system. Kinematic variables such as maximum bat-head speed, swing time, bat angle, joint angles of the upper limbs, and segment angle of the upper trunk were calculated. Differences between TB and MB were analyzed statistically using paired t-test (p<0.05). The maximum bat-head speed was significantly greater in TB than in MB, but swing times divided into 2 phases showed no significant differences between MB and TB. In the first half of the swing, the bat inclination angle was significantly larger in MB than in TB. The joint angles of the barrel-side shoulder abduction, knob-side shoulder adduction and internal rotation were significantly larger in MB than in TB, and those of the barrel-side shoulder internal rotation and individual elbow pronations were significantly larger in TB than in MB. The clockwise rotational angle of the upper trunk was significantly larger in TB than in MB. In the last half of the swing, the joint angles of the barrel-side shoulder abduction, knob-side shoulder flexion and adduction were significantly larger in MB than in TB, and that of the knob-side elbow pronation was significantly larger in TB than in MB. The changes in upper body movement in MB affected the radius of rotation of the bat about the vertical axis to control the bat easily. The movements in the last half of the swing largely resulted from those in the first half of the swing, and did not contribute to timing adjustment. These results indicate that the initial configuration of the bat and upper limbs, and movements at the beginning of the bat swing contribute to the timing adjustment of the bat for a pitched ball. The results of the present study suggest that it could be useful to pay attention to the movement of the bat and upper body in the first half of the swing as TB practice in order to improve timing adjustment.

著者

小池 関也

出版者

バイオメカニズム学会

雑誌

バイオメカニズム学会誌 (ISSN:02850885)

巻号頁・発行日

vol.37, no.4, pp.221-226, 2013 (Released:2016-04-15)

参考文献数

13

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スポーツ動作は,身体各筋の筋張力により生じる関節トルクを主な動力源として発現される高速・高加速な多体系の運動であり,この運動は,多体系としての身体の運動方程式によって支配されている.そこで本稿では,この運動方程式が有する関節トルク入力と身体動作出力との因果関係を利用して,運動の生成に対する,関節トルクの項,重力の項,そして遠心力・コリオリ力からなる運動依存の項などの貢献を定量化する手法について説明するとともに,これら各項の貢献が種目によって大きく異なることを示す.このような定量化は,一見すると複雑な身体運動生成のしくみを簡明に表すこと,そしてパフォーマンス向上に対する力学的な要因を抽出することなどを可能とし,運動のコツを説明することに繋がる.

著者

阿江 数通 小池 関也 藤井 範久 阿江 通良 川村 卓 金堀 哲也

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.16080, (Released:2017-09-01)

参考文献数

48

被引用文献数

1

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The purpose of this study was to compare the kinematic characteristics of the upper body between baseball tee batting and pitched ball batting in order to gain basic knowledge for improvement of batting skill. Ten male collegiate baseball players (age: 20.7±1.1 yr; height: 1.75±0.05 m; body mass: 76.3±7.1 kg; athletic career: 12.7±2.7 yr) participated. They performed two kinds of batting: tee batting (TB) and machine-pitch batting (MB) using a pitching machine (approximate ball speed 33.3 m/s), which were set at middle ball height for the strike zone. Three-dimensional coordinate data were acquired with a motion capture system. Kinematic variables such as maximum bat-head speed, swing time, bat angle, joint angles of the upper limbs, and segment angle of the upper trunk were calculated. Differences between TB and MB were analyzed statistically using paired t-test (p<0.05.) The maximum bat-head speed was significantly greater in TB than in MB, but swing times divided into two phases showed no significant differences between MB and TB. In the first half of the swing, the bat inclination angle was significantly larger in MB than in TB. The joint angles of the barrel-side shoulder abduction, knob-side shoulder adduction and internal rotation were significantly larger in MB than in TB, and those of the barrel-side shoulder internal rotation and individual elbow pronations were significantly larger in TB than in MB. The clockwise rotational angle of the upper trunk was significantly larger in TB than in MB. In the last half of the swing, the joint angles of the barrel-side shoulder abduction, knob-side shoulder flexion and adduction were significantly larger in MB than in TB, and that of the knob-side elbow pronation was significantly larger in TB than in MB. The changes in upper body movement in MB affected the radius of rotation of the bat about the vertical axis to control the bat easily. The movements in the last half of the swing largely resulted from those in the first half of the swing, and did not contribute to timing adjustment. These results indicate that the initial configuration of the bat and upper limbs, and movements at the beginning of the bat swing contribute to the timing adjustment of the bat for a pitched ball. The results of the present study suggest that it could be useful to pay attention to the movement of the bat and upper body in the first half of the swing as TB practice in order to improve timing adjustment.

著者

阿江 数通 小池 関也 川村 卓

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.59, no.2, pp.431-452, 2014 (Released:2014-12-20)

参考文献数

43

被引用文献数

2 3

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The purpose of this study was to clarify the kinetic features of the upper limbs at different hitting-point heights (high, middle, and low) during baseball tee-batting. Twenty-three collegiate male baseball players (age: 19.8±1.3 yr, height: 1.74±0.04 m, weight: 74.1±6.2 kg, athletic career: 12.0±2.1 yr) participated. Three-dimensional coordinate data were captured using a VICON-MX system (12-camera, 250 Hz), and kinetic data for each hand were collected using an instrumented bat equipped with 28 strain gauges (1000 Hz). Three tee-batting heights were set for each subject based on the upper and lower limits of the strike zone according to the rules of baseball. Kinetic variables for the upper limbs, such as joint torque, joint torque power, and mechanical work, were calculated. The period of forward swing motion was divided into down-swing and level-swing phases. The results are summarized as follows: 1) The extension torque and positive torque power at each individual shoulder joint were significantly greater at the low hitting-point height than at other heights. 2) The positive torque power for extension torque at each individual elbow joint in the last half of the down-swing phase was significantly greater at the low hitting-point height than at other heights. 3) Negative power for adduction/abduction torque at each individual shoulder joint in the level-swing phase was observed at the low hitting-point height. 4) The mechanical work done by joint torque about the flexion/extension and adduction/abduction axes at the shoulder, the flexion/extension axis at the elbow, and the palmar/dorsal flexion and radial/ulnar flexion axes at the wrist showed large and positive values, and differed significantly among hitting-point heights. These results indicate that 1) the flexion/extension torque at each individual shoulder joint contributes greatly to adjustment of the translational movement of the bat in the vertical direction during the down-swing phase, 2) the adduction/abduction torque at each individual shoulder joint exerts a larger proportion of the longitudinal force of the bat to withstand centrifugal force at a low hitting-point height than at other heights in the level swing phase, and 3) consequently, it tends to be more difficult to adjust the bat to the hitting-point at a low height in comparison with other heights.

著者

浅井 武 洪 性賛 小池 関也

出版者

筑波大学

雑誌

基盤研究(B)

巻号頁・発行日

2020-04-01

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本研究では,回転,及び無回転(低回転)で自由飛翔するスポーツボール(サッカー,バレー,ラグビー)の飛翔軌跡,非定常流体力,及び非定常渦構造を,3次元モーションキャプチャシステム,ボールインパクトロボット,表面流れ計測用特製ボール(タフトボール),高速カメラ,ステレオ流体可視化システム(Particle Image Velocimetry)を用いて高精度に同時計測し,ボール飛翔軌跡と,流体力,渦構造の関係を検討すると共に,ボールリリース時(インパクトを含む)の初期条件(直線運動と回転運動)やボール変形,打突形状が,ボール飛翔軌跡や非定常流体力に与える影響を明らかにする.

著者

川村 卓 小池 関也 阿江 数通

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

pp.17038, (Released:2019-02-05)

参考文献数

22

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This study examined the flow of energy in the right and left upper limbs of skilled baseball batters during the forward swing motion at different bat head speeds to obtain basic insights that would be useful for batting coaching. The subjects were 23 college baseball outfielders in university teams. The subjects were instructed to hit a ball toward the pitcher from a tee set at a mid-height position. Measurements were taken using 47 points on each subject’s body and 6 points on the bat for a total of 53 points, onto which reflective markers were attached. The 3D coordinates of each marker were measured using a 3D optical motion capture device (Vicon Motion Systems’ VICONMX, 12 cameras, 250 Hz). The variables in the kinetics of each hand were measured using a force detection sensor bat (1000 Hz). The subjects were separated into a faster group of 36.8±0.8 m/s and a slower group of 34.7±1.1 m/s for analysis. In terms of energy transmission, the data revealed that the faster group, in addition to showing additional torque on the knob side shoulder joints, were able to transmit more mechanical energy from the knob side shoulder joints to the end of the upper limbs than the slower group, and that this might be related to an efficient bat head speed. In addition, the faster group showed an increased positive torque power, and transmitted greater mechanical energy to the bat from the hand region. In other words, to prevent mechanical energy from being absorbed while adjusting the bat trajectory near the time of impact, skilled bat control involving movement of the hand joints appeared to determine the bat head speed.

著者

阿江 数通 小池 関也 川村 卓 中島 亮一

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.1, pp.135-149, 2019-06-17 (Released:2019-06-25)

参考文献数

40

被引用文献数

2

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The purpose of this study was to investigate the kinematic characteristics of the lower limbs in relation to the rotation movement of the body based on the moment of the ground reaction force. Twenty-two male collegiate baseball players (age: 19.8 ± 1.3 yr, height 1.75 ± 0.04 m, body mass 73.9 ± 6.2 kg, athletic career:12.1 ± 2.1 yr) participated. They performed baseball tee-batting, set at middle ball height for the strike zone. Threedimensional coordinate data were acquired with a motion capture system (Vicon-MX), and ground reaction force data for both legs were acquired with 3 force platforms. High and low groups (HG and LG) were categorized by the mean peak moment around the vertical axis of the body’s center of gravity caused by the ground reaction force. The period analyzed was that from stride-side foot contact with ground until ball impact, and 2 phases were defined as follows: backward phase, stride-side foot contact with ground until the peak moment of the ground reaction force; forward phase, the end of the backward phase until ball impact. Statistical analysis was conducted using an independent t-test between HG and LG (p <0.05), and the effect size was calculated (small: d = 0.2; middle: d = 0.5; high: d = 0.8). In the backward phase, the flexion angle of both hips was greater in the HG than in the LG at event1 (pivot-side: d = 0.74; stride-side: d =0.97). The abduction angle of the pivot-side hip was significantly greater in the HG than in the LG (stride-side foot contact with ground: d = 0.94; peak moment of the ground reaction force: d = 1.44). In the forward phase, the external rotation angle of the pivot-side hip was significantly greater in the HG than in the LG (d = 1.02), which contributed to the inter-group difference in the internal rotation angle at the instant of stride-side foot contact. These results indicate that the motions of both hip joints acted to rotate the whole body around the vertical axis effectively. The knowledge obtained from this study should provide useful suggestions and insights into coaching for movements of the lower limbs in order to improve batting performance in relation to the rotational movement of the body.

著者

川村 卓 島田 一志 高橋 佳三 森本 吉謙 小池 関也 阿江 通良

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.0812080087, (Released:2008-12-10)

参考文献数

20

被引用文献数

25 4

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The purpose of this study was to analyze three-dimensionally two groups of baseball strikers, i.e. high and low swing speed groups, and to compare the kinematics of their upper limb motion. Sixteen skilled male strikers were videotaped with two synchronized high-speed video cameras operating at 200 Hz. One trial in which the maximum bat head speed was achieved was selected for each subject and digitized to obtain three-dimensional coordinates of the segment end-points and the bat using a DLT technique. Subjects were divided into High (n=8) and Low (n=8) groups according to the bat head speed. The angles compared between the two groups were abduction-adduction, horizontal abduction-adduction, flexion-extension and internal-external rotation for both shoulders, flexion-extension for both elbows, supination-pronation for both forearms, radius-ulnar flexion, and dorsi-palmar flexion for both hands. The sequential data were normalized with the time from the point when the speed of the grip was over 3 m/s to the ball impact, and then averaged.

著者

田島 裕之 土居 孝寛 小池 関也 初田 哲男 中村 純

出版者

一般社団法人 日本物理学会

雑誌

日本物理学会講演概要集 72.2 (ISSN:21890803)

巻号頁・発行日

pp.2817, 2017 (Released:2018-11-13)

著者

沼津 直樹 藤井 範久 森本 泰介 小池 関也

出版者

バイオメカニズム学会

雑誌

バイオメカニズム (ISSN:13487116)

巻号頁・発行日

vol.25, pp.21-32, 2020 (Released:2021-07-16)

参考文献数

14

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本研究ではキッカーにゴールのさまざまな地点へシュートさせ, ゴールキーパー (GK) が実際にダイビング動作によって対応した試技のシュート動作を対象に, GKがシュートの飛来する地点を予測する際に有用なキッカーやボールの動きについてバイオメカニクス的に検討することを目的とした. その結果, 右利きのキッカーが自身の左方向へシュートを行う際, 軸脚の足部や体幹の回旋角度が, 右方向へシュートする場合よりもより左方向へ向くことが明らかとなった. また, シュートがGKの近くまたは遠くに飛来するのかといったシュートの距離や飛来するシュートの高さについては, インパクト後のボールの軌道から素早く判断し, 対応しなければならないことが明らかとなった.

著者

高木 斗希夫 藤井 範久 小池 関也 阿江 通良

出版者

バイオメカニズム学会

雑誌

バイオメカニズム学会誌 (ISSN:02850885)

巻号頁・発行日

vol.34, no.3, pp.216-224, 2010 (Released:2016-04-15)

参考文献数

21

被引用文献数

10 1

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本研究では,野球における速度の異なるボールに対する打撃動作に影響を及ぼす力学的要因を明らかにすることを目的とした.速度の異なるボール(75-80km/h,100-105km/h,125-130km/h)を被験者に打撃させ,3 次元自動動作分析システムを用いて動作を計測するとともに,2 台のフォースプラットフォームを用いて両足下の地面反力を計測した.下肢及び体幹部に作用する関節力および関節トルク,さらに股関節トルクを下胴の長軸周りの軸へ投影した成分(下胴回転成分)などを算出した.その結果,ボール速度の大きい条件では,投手方向への身体の移動に関与する力積が小さく,この要因として踏出足接地から身体重心速度が最大値に到達する時点までの動作時間の短さが大きく影響を及ぼしていた.また,ボール速度の大きい条件では,軸足側では股関節外転トルクの下胴回転成分,踏出足側では股関節屈曲トルクの下胴回転成分が大きく作用していた.

著者

阿江 数通 小池 関也 川村 卓

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

pp.13067, (Released:2014-07-09)

参考文献数

43

被引用文献数

16 3

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The purpose of this study was to clarify the kinetic features of the upper limbs at different hitting-point heights (high, middle, and low) during baseball tee-batting. Twenty-three collegiate male baseball players (age: 19.8±1.3 yr, height: 1.74±0.04 m, weight: 74.1±6.2 kg, athletic career: 12.0±2.1 yr) participated. Three-dimensional coordinate data were captured using a VICON-MX system (12-camera, 250 Hz), and kinetic data for each hand were collected using an instrumented bat equipped with 28 strain gauges (1000 Hz). Three tee-batting heights were set for each subject based on the upper and lower limits of the strike zone according to the rules of baseball. Kinetic variables for the upper limbs, such as joint torque, joint torque power, and mechanical work, were calculated. The period of forward swing motion was divided into down-swing and level-swing phases. The results are summarized as follows: 1) The extension torque and positive torque power at each individual shoulder joint were significantly greater at the low hitting-point height than at other heights. 2) The positive torque power for extension torque at each individual elbow joint in the last half of the down-swing phase was significantly greater at the low hitting-point height than at other heights. 3) Negative power for adduction/abduction torque at each individual shoulder joint in the level-swing phase was observed at the low hitting-point height. 4) The mechanical work done by joint torque about the flexion/extension and adduction/abduction axes at the shoulder, the flexion/extension axis at the elbow, and the palmar/dorsal flexion and radial/ulnar flexion axes at the wrist showed large and positive values, and differed significantly among hitting-point heights. These results indicate that 1) the flexion/extension torque at each individual shoulder joint contributes greatly to adjustment of the translational movement of the bat in the vertical direction during the down-swing phase, 2) the adduction/abduction torque at each individual shoulder joint exerts a larger proportion of the longitudinal force of the bat to withstand centrifugal force at a low hitting-point height than at other heights in the level swing phase, and 3) consequently, it tends to be more difficult to adjust the bat to the hitting-point at a low height in comparison with other heights.

著者

高木 斗希夫 藤井 範久 小池 関也 阿江 通良

出版者

バイオメカニズム学会

雑誌

バイオメカニズム学会誌 (ISSN:02850885)

巻号頁・発行日

vol.32, no.3, pp.158-166, 2008 (Released:2010-12-13)

参考文献数

22

被引用文献数

16 5

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本研究では,球速の異なるボールに対する野球の打撃動作の特徴を明らかにすることで,打撃の正確性に影響を及ぼす動作要因について検討することを目的とした.球速の異なるボール( 75km/h,100km/h,125km/h)を被験者に打撃させ, 3次元自動動作分析システムを用いて動作を計測した.打撃の正確性を評価する指標としてインパクト角を用いて,身体の並進および回転動作と打撃の正確性との関連について検討を加えた.その結果,ボール速度が大きい条件( 125km/h)においては,身体重心の並進移動距離を小さくするとともに,上胴部およびバットの回転動作範囲を小さくすることが打撃の正確性を高める動作であると考えられた.さらに,体幹の捻り角度および捻り戻しの角速度の最大値にはボール速度条件による有意な差は認められなかったため,これらの動作はボール速度に関わらずスイングに必要な動作であると考えられた.

著者

小池 関也 見邨 康平

出版者

一般社団法人 日本機械学会

雑誌

シンポジウム: スポーツ・アンド・ヒューマン・ダイナミクス講演論文集 2015 (ISSN:24329509)

巻号頁・発行日

pp._A-24-1_-_A-24-10_, 2015-10-30 (Released:2017-06-19)

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The purpose of this study was to quantify the contribution of the whole-body joint torques to the generation of evaluation values during baseball batting motion, such as bat head speed and angular motion of the lower trunk in consideration of the joint torque generating mode. The whole-body segments and bat were modeled as a system of sixteen-rigid linked segments, and constraint axes of the elbow, wrist, knee and ankle joints were modeled with anatomical constraint equations in order to consider the degree of freedom (DOF) of the joint. Each hand was considered to be connected with the bat through zero DOF joint. The equation of motion with respect to the whole-body and bat was obtained by considering modelling errors, such as, residual joint force and moment, and fluctuation of segment's length. The dynamic contributions of the joint moments, motion dependent term and gravity term to the bat head speed and angular motion of the lower trunk were derived from the equation of motion for the system. Furthermore, the joint torque was divided into two components, such as eccentric torque component, which shows negative sign of its torque power, and concentric torque component, which shows positive sign of its torque power. The results obtained in this study showed that 1) motion dependent term was the great contributor to the generation of bat head speed and 2) major contributors to the generation of the bat head speed, such as concentric components of knob-side shoulder abduction torque and torso joint rotational torque were quantified by considering main generating factor of motion dependent term.

著者

石川 優希 小池 関也 増村 雅尚 阿江 通良

出版者

一般社団法人 日本体育学会

雑誌

日本体育学会大会予稿集

巻号頁・発行日

vol.58, 2007

著者

阿江 数通 小池 関也 川村 卓

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.17, no.1, pp.2-14, 2013

著者

阿江 数通 小池 関也 川村 卓

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.60, no.2, pp.635-649, 2015 (Released:2015-12-18)

参考文献数

41

被引用文献数

8 2

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The purpose of this study was to clarify the kinetic features of the trunk under different hitting-point height conditions (high, middle, and low) in baseball tee-batting. Twenty-three collegiate male baseball players (age: 19.8±1.3 yr, height: 1.74±0.04 m, whole-body mass: 74.1±6.2 kg, athletic career: 12.0±2.1 yr) participated. Three-dimensional coordinate data were captured using a VICON-MX system (12 cameras, 250 Hz), and kinetic data for the individual hands were collected using an instrumented bat equipped with 28 strain gauges (1000 Hz). Three kinds of tee-batting heights were set for each participant based on the upper and lower limits of the strike zone according to the baseball rule. The torso was modeled with the rigid upper and lower trunk segments connected by a torso joint with three axes: the ante/retro flexion, right/left lateral flexion, and right/left rotation axes. Kinetic variables, e.g. joint force and torque, mechanical power, and mechanical work, were obtained by inverse dynamic calculation. These data were expressed for a right-handed batter and normalized by the time of the forward swing from the swing start to the ball impact as 0-100%, and the time was divided into down-swing and level-swing phases in order to evaluate the mechanical work. From the last half of down-swing phase until ball impact, the retroflexion torque under the low condition was significantly larger than those under other conditions. The left rotation torque and positive torque power showed particularly large values in the level-swing phase regardless of the hitting-point height. The mechanical energy flow generated by the torso joint torque showed inflow from the lower trunk to the upper trunk, and outflow from the upper trunk to the individual upper arms regardless of the height condition over the forward swing. In addition, there were significant positive correlations between the positive mechanical work done by the joint torque about the right/left rotation axis and the maximum bat-head speed during the level-swing phase under the middle and low conditions. These results indicate that 1) the ante/retro flexion axis torque is needed to maintain the configuration of the upper trunk against the large centrifugal force exerted along the bat around the moment of ball impact, 2) the right/left rotation axis torque contributes to the generation of the large mechanical energy, the transfer of energy to the upper limbs, and the generation of the bat-head speed regardless of the height condition.