著者

水島 淳 梶谷 亮輔 九鬼 靖太 柴田 篤志 前田 奎 大山 卞 圭悟 尾縣 貢

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.66, pp.703-714, 2021 (Released:2021-10-20)

参考文献数

28

---

Introduction: The purpose of this study was to investigate the effects of a 4-week barefoot sprint training program on sprint biomechanics and stretch-shortening cycle jump ability. Methods: Fourteen children with no experience in barefoot sprinting were randomly assigned to 1 of 2 groups: a barefoot training group (3 boys and 4 girls; age, 11.0 ± 0.8 years-old; height, 143.1 ± 8.4 cm; body mass, 35.4 ± 5.6 kg; shoe mass, 0.17 ± 0.02 kg) and a control group (3 boys and 4 girls; age, 11.0 ± 0.8 years-old; height, 142.6 ± 8.2 cm; body mass, 34.4 ± 6.4 kg; shoe mass, 0.18 ± 0.01 kg). The 4-week intervention consisted 40 minutes of sprint training per weekly session using the allocated footwear. Before and after the intervention, 2-dimensional biomechanical analysis of the 50-m maximal sprint under both shod and barefoot conditions, and the countermovement jump and 5 repeated rebound jumping tests were performed by both groups. Pre- to post-test changes in spatio-temporal parameters and sprint kinematics, and jump heights for both jump types, and the contact time and rebound jump index for the rebound jump, were analysed using 2-way mixed ANOVA. Results and Discussion: After the 4-week intervention, a higher step frequency (p <0.01), a longer step length (p <0.05), and a higher sprint velocity (p <0.01) were observed in the barefoot training group, although no change was observed in the foot strike patterns and the swing leg velocity. The barefoot training group showed a higher rebound jump index (p <0.05) and a shorter contact time (p <0.01), while no differences were evident in the counter-movement jump height. These results suggest that 4-week barefoot sprint training seems to be an effective strategy for improving certain aspects of sprint biomechanics and for development of fast stretch-shortening cycle ability in children.

著者

九鬼 靖太 土橋 康平 竹澤 健介 若吉 浩二

出版者

大阪経大学会

雑誌

大阪経大論集 (ISSN:04747909)

巻号頁・発行日

vol.72, no.3, pp.119-126, 2021 (Released:2021-09-28)

---

This study aimed to investigate the acute effects of sprint training on sprint motions evaluated by the observational motion assessment method and sprint velocity in elementary- and middleschool students. 38 elementary- and middle- school students performed 50m sprint tests before and after the 30-min training intervention, consisting of the mini-hurdle sprinting and the rebound jump exercises. The sprint velocity from 20m to 40m was measured as the mean sprint velocity. The sprint motion was captured by video cameras, and it was qualified using the observational motion assessment method. No significant change was found in the mean sprint velocity between pre and post sprint tests(P=0.567, d=0.020). Meanwhile, the scores of the motions, such as the direction of arm swinging(P=0.001, d=0.405), the range of motion of the legs(P=0.031, d=0.191)and the timing of the scissors motion(P=0.029, d=0.304)were significantly improved in the post test. Therefore, our results suggested that acute sprint training did not improve the sprint velocity, but sprint motions.

著者

竹澤 健介 九鬼 靖太 前田 知良 若

出版者

大阪経大学会

雑誌

大阪経大論集 (ISSN:04747909)

巻号頁・発行日

vol.70, no.6, pp.17, 2019 (Released:2020-04-04)

著者

岡野 憲一 山中 浩敬 九鬼 靖太 谷川 聡

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.16068, (Released:2017-03-13)

参考文献数

29

被引用文献数

3

---

This study examined for the first time the correlation between the spike jump (SPJ), an action specific to volleyball, and other jumps among 202 top-level male volleyball players from domestic leagues (84 from the V. League and 118 from the first division of the Kanto University Volleyball Association). We then categorized the ability of the players during stretch-shortening cycle exercise (SSC) to examine the characteristics of SPJ performance and other positions. The results indicated that, on the one hand, ability in both the counter movement jump (CMJ) and rebound jump (RJ) is required for the SPJ, RJ showing more prominence among elite players. On the other hand, for SSC ability, exercise requiring a longer duration, such as the CMJ, was found to be more critical for the SPJ with a one-step run-up. In terms of different player positions, the results suggested that a middle blocker (MB) with a shorter run-up required a jump that exerts force through longer-duration SSC exercise, whereas a wing spiker (WS) with a full run-up demonstrated more ballistic SSC exercise in his jump. On the basis of these findings, this study has shown the importance of evaluating the characteristics of jump performance according to each player position when designing or choosing the most appropriate physical training exercises for volleyball players.

著者

太田 和希 九鬼 靖太 奥平 柾道 吉田 拓矢 前村 公彦 谷川 聡

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.33, no.2, pp.145-159, 2020-03-20 (Released:2020-06-11)

参考文献数

38

---

This study aimed to clarify the step variables and three-dimensional joint kinematics of the pelvis while increasing running speed on a treadmill. Sixteen male track and field athletes ran on an instrumented treadmill at three different running speeds: 4.0, 6.0, and 8.0 m/s. The step variables, such as step frequency, step length, contact time, and flight time, and the kinematic data of each running speed were recorded using a high-speed video camera (300 fps) and a Vicon T20 system (250 Hz). In addition, the pelvic angular displacement (Δ) was calculated by subtracting the minimum from the maximum values of the pelvic angle in the stance phase. The results were as follows: (1) Stride length and step frequency were significantly greater at higher running speeds. Although contact time was significantly shorter at the faster speeds, flight time was significantly shorter when transitioning from 6.0 to 8.0 m/s and from 4.0 to 8.0 m/s. (2) The pelvis of the swing leg side elevated from toe off to early half of swing phase with increasing running speeds. In addition, the pelvis of the stance leg side rotated to the swing leg side from mid stance phase to toe off with increasing running speeds. (3) Δelevation showed a significant negative correlation with step frequency but a significant positive correlation with stride length for each running speed. In addition, Δrotation showed a significant positive correlation with step frequency but a significant negative correlation with stride length at 8.0 m/s.     Therefore, increased pelvic elevation improves the stride when transitioning from a low to high speed, and increased pelvic rotation leads to a higher step frequency during the stance phase when running at 8.0 m/s. In addition, it was suggested that it is necessary to run at minimum 8.0 m/s for the pelvis to behave differently compared with running at slower speeds to learn the high speed running movement.

著者

岡野 憲一 山中 浩敬 九鬼 靖太 谷川 聡

出版者

日本体育学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.62, no.1, pp.105-114, 2017

---

This study examined for the first time the correlation between the spike jump (SPJ), an action specific to volleyball, and other jumps among 202 top-level male volleyball players from domestic leagues (84 from the V. League and 118 from the first division of the Kanto University Volleyball Association). We then categorized the ability of the players during stretch-shortening cycle exercise (SSC) to examine the characteristics of SPJ performance and other positions. The results indicated that, on the one hand, ability in both the counter movement jump (CMJ) and rebound jump (RJ) is required for the SPJ, RJ showing more prominence among elite players. On the other hand, for SSC ability, exercise requiring a longer duration, such as the CMJ, was found to be more critical for the SPJ with a one-step run-up. In terms of different player positions, the results suggested that a middle blocker (MB) with a shorter run-up required a jump that exerts force through longer-duration SSC exercise, whereas a wing spiker (WS) with a full run-up demonstrated more ballistic SSC exercise in his jump. On the basis of these findings, this study has shown the importance of evaluating the characteristics of jump performance according to each player position when designing or choosing the most appropriate physical training exercises for volleyball players.<br>

著者

岡野 憲一 九鬼 靖太 秋山 央 谷川 聡

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.355-366, 2018-06-10 (Released:2018-06-20)

参考文献数

32

---

This study focused on volleyball spike jump performance. We classified players based on different types of jumping ability and tested the effects of strength training and plyometrics for each type of ability. Players who excelled in their ability to acquire greater impulse (countermovement jump or CMJ type) showed no significant changes in spike jump height with strength training (improvement in maximum muscle strength), but demonstrated a significant improvement in jump height after plyometrics. In contrast, players with outstanding execution of ballistic movement (rebound jump or RJ type) showed a significant improvement in their spike jump height with strength training (an improvement in maximum muscle strength), but a significant loss of jump height after plyometrics. This reveals that the same training program results in players jumping lower or higher, depending on the jump type. When formulating training to improve the jump height of volleyball players, these results suggest that the type of training must be selected based on the individual player’s jumping ability.