著者

前田 正登

出版者

日本スポーツ産業学会

雑誌

スポーツ産業学研究 (ISSN:13430688)

巻号頁・発行日

vol.15, no.2, pp.33-41, 2005-09-30 (Released:2010-07-27)

参考文献数

5

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The present study focused on the behavior of the ball at the time of the stroke in soft tennis, and it aimed at exploring the relations of many kinematic values at impact, and the flight behavior of the ball, while checking whether there might be an abnormal flight behavior. The flight of the ball was videotaped by three sets of video cameras, and the ball at impact was videotaped with two high speed cameras. The behaviors of these balls were analyzed. These experiments investigated the conditions of the flights of soft tennis balls, both when given a lift from an applied drive rotation and when given a sinking flight from a slice rotation. It was suggested that the difference in rate of spin given by a stroke influenced the abnormal flight behavior of a soft tennis ball, and also that when there was drive rotation or slice rotation of 40rps or more, the possibility of abnormal flight behavior occurring was high.

著者

杉本 祐太 前田 正登

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.26, no.2, pp.145-154, 2013-03-20 (Released:2019-09-02)

参考文献数

9

被引用文献数

1

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Subjective effort is an adjustment in output performance, dependent on an athlete’s perception and it is an important factor in sprint training. To gain information about utilizing subjective effort in sprint training, this study investigates changes in sprint running movement due to the different subjective effort of athletes at various performance levels. The participants were 15 male collegiate sprinters, who were divided into high-level (n=7) and low-level (n=8) groups based on their personal best times in the 100 m dash. The participants performed 50 m sprints at five levels of effort ranging from 60% to 100%, with increases at 10% intervals. The final 10 m of each sprint was recorded by two high-speed video cameras to analyze each participant’s movement. The results are summarized as follows.     The decline in sprint speed at lower subjective effort was higher for the low-level group than high-level one. This was the reason why low-level group decreased swing back velocity of the leg with the change of knee joint angle increased below a subjective effort of 70%. And the achievement of sprint speed from a subjective effort of 90% to maximum effort was not practical because of knee extension during support phase. Moreover, below a subjective effort of 70%, the low-level participants’ movement during support phase differed from that of maximum effort sprint running. In contrast, the high-level participants’ movement was the same even a subjective effort of 60%.

著者

篠原 康男 前田 正登

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.15096, (Released:2016-08-29)

参考文献数

39

被引用文献数

1

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This study aimed to clarify the composition of the phases (acceleration, full sprint, and velocity endurance) in the 50-m sprint as performed by elementary school students, focusing on changes in running velocity. The subjects were 169 boys and 178 girls in the first to sixth grades of elementary school, who performed a 50-m sprint from a standing start. Running velocity was measured using a laser distance meter, which was synchronized with a video camera that recorded the entire sprint. It was found that the running time of the total sprint was significantly shorter and that maximal velocity was significantly higher for higher-grade than for lower-grade students. The distances of the acceleration phase and full sprint phase were significantly longer for higher-grade than for lower-grade students, but there was no significant difference in the duration of these phases by grade. However, both the distance and duration of the velocity endurance phase were significantly shorter for higher-grade than for lower-grade students. Step length in the acceleration, full sprint, and velocity endurance phases was longer for higher-grade than for lower-grade students. However, step frequency at each phase tended to be almost equal or slightly lower for higher-grade than for lower-grade students. The SL index for higher-grade boys tended to be higher than for lower-grade boys. However, for girls, there was little difference in the SL index at each phase for second-grade students or above. Taken together, the results indicate that the velocity endurance phase comprises the majority of the 50-m sprint when performed by lower-grade students. However, for higher-grade students, the velocity endurance phase is shorter due to the relative increases in the acceleration and sprint phases. This suggests that the distance of the acceleration and full sprint phases affects the distance and duration of the velocity endurance phase.

著者

篠原 康男 前田 正登

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.13007, (Released:2013-10-11)

参考文献数

35

被引用文献数

3

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The forces applied to the starting blocks are an important aspect of a sprint start. For achieving the most effective start, however, the relationship between these forces and block clearance has not been clarified. In this study, an experiment was conducted with collegiate sprinters in order to elucidate this relationship. The 19 male participants performed a start dash from the blocks as in a typical sprint race, and the forces applied to the front and rear starting blocks, as well as to the ground during the first step, were measured with force plates. The following results were obtained. Based on the impulses applied to the starting blocks, the horizontal impulse component had a greater effect than the vertical impulse component at block clearance. Furthermore, at block clearance, the horizontal component of the impulse applied to the front block accounted for a large proportion of the total horizontal impulse applied to the starting blocks. However, there was a significant correlation between the horizontal component of the impulse applied to the rear block and the total horizontal impulse applied to the starting blocks. The horizontal component of the impulse was affected by the duration of force application to the blocks. Moreover, the horizontal component of the impulse applied to the starting blocks was unrelated to block placement. This indicates that the component was affected by the position of the sprinter relative to the front and rear blocks. Lastly, the horizontal impulse component at block clearance affected the sprint start until grounding of the first step, after which this relationship differed according to the starting strategy and grounding skill of individual participants.

著者

前田 正登

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.12, no.1, pp.193-201, 1999-03-31 (Released:2021-03-31)

著者

岸本 恵一 神田 かなえ 日下 昌浩 大槻 伸吾 大久保 衞 前田 正登 柳田 泰義

出版者

一般社団法人 日本アスレティックトレーニング学会

雑誌

日本アスレティックトレーニング学会誌 (ISSN:24326623)

巻号頁・発行日

vol.3, no.1, pp.67-70, 2017

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<p>アメリカンフットボール競技の現場で重症度判定が適切でなかった熱中症の症例を経験した.主訴は全身性筋痙攣であり,当初は意識清明であるとの評価から軽症な熱中症を疑ったが,採血結果から重症熱中症(III度熱中症/熱射病)と診断された.スポーツ現場で利用可能な重症度判定指標は限られるため,暑熱環境下での体調不良は重症熱中症の可能性を疑い,可及的早期に病院を受診することが望ましい.</p>

著者

前田 正登

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

巻号頁・発行日

vol.2016, pp.B-11, 2016

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<p>In this study, throwing experiments were conducted with the participation of six javelin throwers using a wooden javelin produced to conform to the current regulations for javelin throw competitions and a normal javelin made by duralumin. In the experiments, the wooden javelin and duralumin javelin were thrown and the following release parameters were measured: initial velocity, release height, release angle, attitude angle, and angle of attack). The distances of the throws were measured and the effects of the release parameters were assessed. As a result, it was found that the thrown distance of the wooden javelin was slightly shorter than that of the duralumin javelin, but the difference was not significant. Similarly, no significant difference was observed in each release parameter. The standard deviation of each release parameter was relatively large, and individual differences between the throwers were considered to be one of the causes.</p>

著者

前田 正登

出版者

神戸大学

雑誌

身体行動研究 (ISSN:21868719)

巻号頁・発行日

vol.5, pp.1-7, 2016

著者

西田 勇 前田 正登 川野 常夫 白瀬 敬一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.840, pp.16-00006-16-00006, 2016 (Released:2016-08-25)

参考文献数

11

被引用文献数

1

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For several decades, factory automation or unmanned factory productivity has been progressed to realize much higher productivity in manufacturing. However, human centered manufacturing system is getting attention to realize much more flexibility for manufacturing of wide product variety and volume. So it is necessary to provide the safe and efficient environment to workers considering their own physical properties. This study investigated a mechanism of muscle fatigue and proposed a muscular fatigue model to evaluate muscle fatigue progress under several muscular force patterns. Previous studies have already proposed a muscular fatigue model. However, these previous studies discussed about the condition of maximum voluntary contraction. The new point of this study is considering several muscular force patterns including muscle recovery progress. This study proposed the method to estimate the endurance times for keeping constant forces considering the physical characteristics. This study also proposed the method to estimate the iteration numbers for keeping constant forces with interval. To validate the effectiveness of the proposed method, experimental verifications were conducted. The experimental results had a good agreement with the evaluation of muscle fatigue progress using the proposed method although it is necessary to consider the method to raise the precision of determining the physical parameters and the method to decrease the dispersion of experiments derived from the subjective judgement of participants. Success of resolving these issues will provide ergonomically safe and efficient working environments considering the physical properties of each worker.

著者

高橋 昌宏 前田 正登 野村 治夫

出版者

社団法人日本体育学会

雑誌

日本体育学会大会号

巻号頁・発行日

no.50, 1999-09-15