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

森本 吉謙 伊藤 浩志 島田 一志 川村 卓 阿江 通良 村木 征人

出版者

日本コーチング学会

雑誌

コーチング学研究 (ISSN:21851646)

巻号頁・発行日

vol.16, no.1, pp.13-26, 2003-03-31 (Released:2021-03-31)

著者

川村 卓 島田 一志 高橋 佳三

出版者

筑波大学体育センター

雑誌

大学体育研究 (ISSN:03867129)

巻号頁・発行日

no.28, pp.63-71, 2006-03

著者

青山 敏之 阿江 数通 相馬 寛人 宮田 一弘 梶田 和宏 奈良 隆章 川村 卓

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.70, no.1, pp.91-100, 2021

被引用文献数

2

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<p>The yips represent a disorder that makes it challenging for an individual to perform automatic and coordinated movements in sports activities. The cause of the yips is not sufficiently clarified, and limited information is available regarding throwing yips in baseball. Therefore, this study was designed to clarify the incidence and characteristics of the throwing yips among college baseball players. Total 107 players of the college baseball team participated in the study and completed the questionnaire by answering questions about their experience of the yips (loss of control to throw the ball accurately for more than 1 month), the symptom intensity, and changes observed in the symptoms in different situations. The 47.1% of players met the definition of throwing yips. The symptoms of the yips were more pronounced with short-distances and low intensity of throwing. Moreover, there were various subjective symptoms, such as the issue about co-contraction of the upper limb, sensory function, body ownership, and movement planning. Various physical symptoms associated with throwing yips suggest that the yips are not only a disorder of motor skills, but result from movement disorders. The present results show that the occurrence of the yips depends on the throwing condition; this finding provides useful insights into the mechanism and the treatment of the yips. Interdisciplinary studies that aim to elucidate the cause of the yips and develop effective intervention are necessary.</p>

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

川村 卓也

出版者

臨川書店

雑誌

国語国文 (ISSN:09107509)

巻号頁・発行日

vol.89, no.4, pp.43-60, 2020-04

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.

著者

島田 一志 川村 卓

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 第62回(2011) (ISSN:24241946)

巻号頁・発行日

pp.149, 2011-09-25 (Released:2017-04-06)

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

vol.53, no.2, pp.423-438, 2008-12-10 (Released:2009-02-25)

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.1 Angles of elbow extension, forearm supination of the top arm, and ulnar flexion of both hands were much changed. However, the angles of both shoulder joints, bottom elbow and bottom forearm showed little change.2. The High group showed significantly larger shoulder adduction and horizontal adduction of a bottom arm than the Low group in 0–10% time and 50–70% time (p<0.05). The High group showed significantly smaller top elbow extension than the Low group in 40–70% time and 90–100% time (p<0.05).3. The High group showed significantly smaller top hand supination than the Low group in 100% time. In the time, the High group showed significantly larger bottom forearm pronation than the Low group in 50–70% time (p<0.05). The High group showed significantly larger dorsiflexion of the bottom hand than the Low group in 20–30% time (p<0.05).

著者

川村 卓 功刀 靖雄 阿江 通良 Kawamura Takashi Kunugi Yasuo Ae Michiyoashi

出版者

筑波大学体育センター

雑誌

大学体育研究 (ISSN:03867129)

巻号頁・発行日

no.22, pp.19-32, 2000-03

著者

梶田 和宏 川村 卓 島田 一志 八木 快

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.66, pp.319-320, 2015

著者

森本 吉謙 入澤 裕樹 坪井 俊樹 小野寺 和也 川村 卓

出版者

The Japan Journal of Coaching Studies

雑誌

コーチング学研究 (ISSN:21851646)

巻号頁・発行日

vol.32, no.2, pp.203-210, 2019-03-20 (Released:2019-09-02)

参考文献数

23

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The purposes of this study were to investigate the relationship between competitive result and environmental factors in high school baseball. A questionnaire survey was conducted on 533 university students who belonged to the baseball club when they were in high school. The survey content was the following 11 items; 1. Highest competitive result, 2. Presence or absence of the sports recommendation entrance examination, 3. Presence or absence of the sports scholarship system, 4. Occupation of the head coach, 5. Presence or absence of the assistant coach, 6. Number of the assistant coach, 7. Occupation of the assistant coach, 8. Presence or absence of the selection system for enter the club, 9. Number of the members, 10. Type of school (public or private), 11. Presence or absence of the private facility. In case of high school duplication, only one answer was adopted, and other inappropriate invalid answers were excluded for totalization. Finally, 435 students were divided into national group (n=89), block group (n=82) and prefecture group (n=264), based on the best result of the team at the time of high school, and examined the relationship between the competitive result and each environmental factor. As a result, regarding the occupation of the head coach, the proportion of teachers in all groups was high, but in the other items, the relationship with the competitive result was indicated, and the possibility that the difference in these environments could affect the competitive result was shown.

著者

入澤 裕樹 川村 卓 岡出 美則 森本 吉謙

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.59, 2008

著者

峰松 美佳 後藤 真孝 川村 卓也 松澤 茂雄

出版者

情報処理学会

雑誌

情報処理学会論文誌 (ISSN:18827764)

巻号頁・発行日

vol.54, no.2, pp.551-560, 2013-02-15

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同時により多くの情報を表示可能とするタイルドディスプレイシステムが注目を集めている.本論文では,ディスプレイの大型化に柔軟に対応することを目的とした,マルチコアレンダリングサーバの設計と実装について述べる.また,我々の特徴技術である,多段並列処理手法と背景補正ダブルフレームバッファ(FB)の効果を検証する.8CPUコアサーバを用いて性能評価した結果,フレームレートが,並列処理を行わない場合と比べて7.3倍,通常のダブルFBを利用する場合と比べて1.3倍向上することが確認できた.また,関連研究であるXvncと比較すると5倍のフレームレートが得られた.A tiled display system which enables to display large amount of data is gaining attention. In this paper, we propose multi-core rendering server architecture for a tiled display system which flexibly adapts to different display sizes. The proposed technology introduces multistage parallel processing method and background correction double FB (Frame Buffer). Evaluation using 8 CPU core server showed that the frame rate of the proposed technology increased by 7.3 times compared with single thread version, increased by 1.3 times compared with conventional double FB version, and increased by 5 times compared with Xvnc.

著者

松尾 知之 平野 裕一 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.58, no.1, pp.195-210, 2013 (Released:2013-06-08)

参考文献数

18

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Expert players and/or expert coaches have a large stock of experiential knowledge, including knowledge of movement-related causality. We attempted to extract experiential knowledge of movement-related causality in baseball pitching from expert players and coaches with sufficient creditability. Verbal data collected in a previous study (Matsuo et al. 2010) using semi-structured interviews with four former professional baseball pitchers and seven expert baseball coaches were used for this study. The data had been categorized on the basis of a wide variety of coaching points. A matrix of co-occurrence based on the verbal data was used to calculate the strength of association between pairs of categories. In the process of the calculation, we employed the matrix calculation utilized in the Dematel method to count indirect associations. The distances among categories, calculated on the basis of co-occurrence probability, were used to assess the creditability of the verbal data. The categories were mapped into three-dimensional space using the least squares method, based on the distances. The associations of categories were extracted as highly trustworthy when the root mean squared error between the original distances and the mapped distances was below 10%. Among the extracted associations, the direction of causality was added to the associations that expressed the causality explicitly among the verbal data. The major selected causalities were as follows:1)  Moving forward before placing weight on the pivot foot sufficiently opens the trunk earlier and leads to insufficient weight being placed on the stride foot.2)  An inadequate take-back action, especially excessive horizontal abduction and elbow extension, limits the flexible arm movement around throwing-side ear and leads to lower shoulder abduction. In addition, it makes the trunk open earlier.3)  Excessive lead elbow extension during the stride phase makes the trunk open earlier. How the lead-arm is pulled towards the trunk also affects trunk rotation.4)  Bending the neck at any point leads to inadequate trunk rotation.

著者

奈良 隆章 川村 卓 島田 一志 Nara Taka-aki Kawamura Takashi Shimada Kazushi

出版者

筑波大学体育センター

雑誌

大学体育研究 (ISSN:03867129)

巻号頁・発行日

no.33, pp.1-10, 2011-03