著者

吉田 拓矢 松島 一司 林 陵平 図子 あまね 苅山 靖

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.17129, (Released:2018-08-06)

参考文献数

37

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The purpose of this study was to evaluate the multistep drop jump (DJ) test in elite jumpers according to changes in test performance, ground reaction force, and lower limb joint kinetics with changes in drop height. Male jumpers (n=10) performed a DJ from 4 drop heights (0.3, 0.6, 0.9, and 1.2 m). The DJ-index was calculated by dividing the jump height by the contact time. The rate of change of the DJ-index (a/b) was the slope/intercept of the regression line (Y = aX+ b) derived from 4 values of the DJ-index for each subject. Jump motions in the sagittal plane and ground reaction force data were recorded using a high-speed camera and force platform, respectively. The DJ-index was lower at 1.2 m than at other drop heights. The contact time increased along with the drop height. There was no significant difference in jump height between the drop heights. The amount of negative work by 3 lower extremity joints increased with increasing drop height. The jump events performance (IAAF Score) and DJ-index at each drop height only showed a significant correlation at 1.2 m. The correlation between IAAF score and a/b was significant between these variables. According to individual characteristics, increased drop heights were associated with different patterns of change in the DJ index. Therefore, subjects were grouped according to characteristics using a/b as an index. Sub.A, who had the highest jump-event performance in the study, had participated in international meetings, and had won a medal at the World Junior Championships. The DJ-index for this subject at 0.3 m was close to the mean value, but at 1.2 m was highest among all the subjects. In contrast, the DJ-index for Sub.C at 0.3 m was highest among the subjects. However, the DJ-index decreased greatly with an increase from 0.3 m to 1.2 m. Therefore, to evaluate the performance of jumpers, it is important to use a varied range of heights, including a higher drop height (approximately 1.2 m), focusing on the rate of change with increasing drop height.

著者

丹治 史弥 鍋倉 賢治

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.2, pp.583-594, 2018-12-10 (Released:2018-12-20)

参考文献数

38

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Step parameters are associated with running economy (RE), but the relationship between these longitudinal changes remains unclear. In the present study, we aimed to clarify the relationship between changes in step parameters and RE at intensities below and above the lactate threshold (LT) in well-trained middle to long-distance runners and to acquire knowledge applicable to coaching. A total of 29 male university students training in distance running (age, 19.4 ± 1.0 yr; height, 171.3 ± 4.5 cm; body weight, 57.1 ± 3.6 kg) participated in the study. Participants performed multistage incremental treadmill tests to measure step parameters (ground contact time: CT; step length: SL; step frequency: SF; leg stiffness: kleg) and RE before and after 4 months of training. Since the LT speed of participants was 16.6 ± 1.1 km・h−1, intensities below, near, and above the LT were set at 13.8 and 15.0 km・h−1, 16.2 km・h−1, and 17.4 and 18.6 km・h−1, respectively. No significant relationships were observed between changes in RE and any of the step parameters at intensities below and near the LT. Moreover, although no significant relationship was noted between changes in RE and both SL and SF, there was a significant positive and negative relationship between changes in RE and CT and kleg, respectively, at intensities above the LT. Changes in kleg showed a strong negative correlation with CT changes at each intensity. It can be concluded from these findings that shortening the CT improves the RE for high-intensity running and that this variation is partly attributable to the improvement in kleg.

著者

苅山 靖 渡来 真人 図子 浩二

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.755-770, 2014 (Released:2014-12-20)

参考文献数

35

被引用文献数

1 4

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This study aimed to clarify the importance of strength and jump ability of both the kicking and supporting legs for increasing the speed of a soccer ball during instep kicks at various approach speeds. Twelve male university soccer players performed instep kicks using different approach lengths (1 m, 3 m, 7 m, and free length). Maximal isokinetic and concentric muscular strength was measured in terms of knee extension/flexion, hip extension/flexion, and hip abduction/adduction using an isokinetic dynamometer. Jump ability was measured using countermovement jump, double-leg rebound jump, and single-leg rebound jump with the kicking leg and supporting leg. For the instep kick, kinematic and kinetic data were recorded using the Vicon T20 system (250 Hz) and force platforms (1000 Hz). The results of the analyses were as follows:   1.  The approach speed increased as the approach length increased. Moreover, the time between the moment when the foot touched the ground and the moment of ball impact became shortened, and the ground reaction force at all axes increased as the approach speed increased.   2.  Foot speed under all the approach conditions was correlated with hip extension and the abduction strength of the supporting leg.   3.  Foot speed for the 3 m, 7 m, and free-length conditions was correlated with the rebound jump ability of the supporting leg. Moreover, foot speeds for the 3 m, 7 m, and free-length conditions was correlated with hip adduction strength of the supporting leg.   4.  Similar results were obtained for relative foot speed (calculated by dividing foot speed by the speed of the body's center of gravity at the moment of ball impact).   5.  The rate of change in the relative foot velocity (for an approach of 1 m to 7 m) was correlated with the rebound jump ability of the supporting leg.   These results suggest that it is important to improve hip extension and the abduction strength of the supporting leg in order to increase the ball speed, regardless of the approach speed. In addition, it is important to improve the hip adduction strength, especially the rebound jump ability of the supporting leg in order to increase the ball speed when a high approach speed is employed.

著者

松田 太希

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.407-420, 2016 (Released:2016-12-14)

参考文献数

25

被引用文献数

2

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The purpose of this study is to confirm aspects of violence at school athletics clubs related to the use of corporal punishment, and to clarify the significance of corporal punishment in terms of how it is perceived by teachers and students.  Recently, there has been a large volume of research on corporal punishment, under the premise that its use is questionable. Such a premise tends to encourage reasons for denying it occurs, or turning a blind eye to how it affects relationships between teachers and students at school athletics clubs. However, in order to clarify the significance of corporal punishment in school athletics clubs, it is essential to understand interpersonal relationships in this type of setting.  The ethos of school athletics clubs is to impose the desirable norm on students (i.e., to make them good players). This means that students need to develop self-discipline in order to succeed at their sport, and corporal punishment is used to impose normalization of self-discipline in students. This leads to an association between pain and the perceived pleasure of success in the mind of the students. According to Butler, conscience is the means by which a subject can reflecting on oneself, and conversion of pain into the pleasure is a method by which this can be achieved. In other words, a panacea for preempting existential negation.  On the other hand, for teachers, corporal punishment is deeply related to their existence and desire for self-protection. Adorno and Horkheimer's arguments on the reasons for the relation between reason and violence in Dialectic of Enlightenment: Philosophical Fragments teach us that the desire for self-protection is expressed by using violence, for example corporal punishments, on others. Teachers regard students as a means for their self-protection to secure their role as a teacher, which is based on a pre-existing relationship with students. However, the role of teachers is threatened when a school athletics club achieves poor results. Thus, teachers employ corporal punishment as a means of maintaining their authoritative role.  The findings of this study argue that corporal punishment in school athletics clubs deeply reflects the relationship between students and teachers. It is necessary to discuss this issue rather than ignoring it.

著者

瀧川 寛子 堀内 元 田内 健二

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.65, pp.143-152, 2020 (Released:2020-02-25)

参考文献数

18

被引用文献数

1

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The purpose of this study was to investigate motion factors in female javelin throwers during success and failure trials from a biomechanical standpoint. Fourteen throwers who participated in the Japanese Women’s Javelin Championships Final were investigated during both success trials and failure trials and the results were compared. The success trial was set as the best record and the failure trial as the worst record. Timing points of throwing motion were set at right foot contact (R-on), left foot contact (L-on) and javelin release (REL). The main results were as follows; 1) There was no significant difference in approach velocity between the success and failure trials. 2) In the success trials, peak speeds of the right shoulder, elbow joint and javelin were higher than those in the failure trials. 3) In the success trials, the left rotation velocity of the shoulder angle was larger than that in the failure trials just after L-on. 4) In the success trials, the forward rotational velocity of the trunk was larger than that in the failure trials just after L-on. 5) In the success trials, the throwers maintained a more extended position of the left knee angle than in the failure trials between L-on and REL. These results revealed that superiority or inferiority for female javelin throwers at the same competition level was determined not by the approach velocity, but by the blocking motion of the left leg. Although the importance of this left leg blocking motion has been reported many times in previous studies of throwers with different performance levels, it has been shown here to play an important role in the success of individual performance.

著者

大下 和茂 萩原 悟一 門間 貴史 津野 天兵 小泉 和史 大山 泰史 山口 恭平 田代 智紀 船津 京太郎

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.539-550, 2015 (Released:2015-12-18)

参考文献数

30

被引用文献数

4 1

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The aim of the present study was to investigate the effect of experience or inexperience with weight-training under appropriate supervision on knowledge of squatting exercises among university students. A questionnaire-based survey was conducted among university students who exercised regularly (30 or more min per day, 2 or more days per week, and maintaining this for more than 1 year) to clarify the relationships between their experience of weight-training under appropriate supervision, knowledge of squatting exercises, and the frequency with which they perform squatting exercises (n=309). More than half of the students who exercised regularly had never experienced weight-training under appropriate supervision. Approximately 50% of the participants performed squats periodically, even if they did not have any experience with weight-training under appropriate supervision. The participants who lacked experience with weight-training under supervision had made significantly fewer attempts to consciously train their gluteal and knee flexor muscles during squatting exercises than those who had experienced weight-training under supervision. In fact, approximately 50% of the former did not consciously train their gluteal muscles during squatting exercises at all. These results suggest that although the students performed squatting exercises periodically, those who had never experienced weight-training under supervision may not have properly understood the squatting method. Therefore, to enhance the benefits of training, people should be shown the correct method for performing training exercises and given appropriate supervision.

著者

那須 大毅 松尾 知之

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.303-313, 2015 (Released:2015-06-13)

参考文献数

12

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The aim of the present study was to investigate the differences in kinematics between 2 types of motor strategy for expert dart throwing. We divided 8 experts into 2 groups based on the motor strategies they had demonstrated in a previous study (Nasu et al., 2014): group A were experts who had a longer time window in which a release could result in hitting the bull's eye, and group B were experts who had a shorter time window but greatly reduced their timing error. Each subject performed 60 dart throws, aiming at the center of the dart board (bull's eye). The movement of the dart, index finger, and joint motion of the upper extremity were captured using a motion capture system with 7 cameras (480 Hz, Oqus300, Qualysis Inc.). We compared the shape of the hand trajectory and joint kinematics between the groups. We found that experts in group A demonstrated a smaller shoulder angle (lower elbow height) and a larger angle of elbow flexion through forward swing than those in group B. These differences affected the time window that led to a successful throw, i.e. the time for which the mutually complementary relationship among the release parameters (especially the relationship between velocity and direction of motion) was maintained. These results may be useful as basic data to help clarify how throwing accuracy can be improved in several sports.

著者

徳永 幹雄 橋本 公雄 千綿 俊機

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.16, no.2, pp.109-114, 1971-10-01 (Released:2017-09-27)

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この研究は大学生の体格(身長,体重,ローレル指数),体力(体力診断テスト),性格(Y-G性格検査)の相互関係を明らかにするために行ない,つぎの結果を得た.1. 体格と体力の関係:体型の中間型が体力にすくれ,細長型が劣っていた.身長,体重と体力の間に有意味の関係があることが明らかになつた. 2. 性格と体格の関係: E類型に細長型が多く, Y-G得点では細長型と肥満に近い型には差はなく,中間型に比較し細長型は神経質大で,肥満に近い型は劣等感大であつた.また,外向的な学生は平均型の学生より体重が重かつた.3. 性格と体力の関係:D類型が最も体力がすくれE類型が最も体力の低い学生が多かつた.また,体力の低い学生は体力の高い学生に比較し劣等感大,神経質大,主観的,非協調的,のんきでない,服従的,社会的内向であつた.積極型の学生は消極型の学生より筋力にすくれていた.

著者

平嶋 裕輔 浅井 武 深山 知生 中山 雅雄

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.17088, (Released:2018-04-16)

参考文献数

13

被引用文献数

2

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The present study was verify of reliability and validity the regression equation constructed using the game footage from the 2010 FIFA World Cup. Formulated using multivariate logistic regression analysis, this equation’s purpose was to predict the probability of a goalkeeper’s failure to stop shots at goal. The 2014 dataset consisted of 587 shots at goal from within the frames during 64 games played by 32 teams that participated in the FIFA World Cup in Brazil. The results showed that for the probability of failing to block a shot predicted by the regression equation, the two inter-rater interclass correlation coefficient was high (0.91), thus demonstrating reliability. Furthermore, when a contingency table was created with a cut-off value of 0.5, accuracy was high (85.9%); when an ROC curve was drawn and the area below the curve was measured (0.874), it was notably distinct, indicating generalizability. Therefore, the regression equation predicting the probability of failure to block a shot has high generalizability for predicting world-class goalkeepers’ probability of failure to block shots. This is considered a useful formula for evaluating goalkeepers’ blocking ability.

著者

裵 芝允

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.17037, (Released:2018-02-15)

参考文献数

28

被引用文献数

1

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The purpose of this paper is to extend understanding of Richard Shusterman’s somaesthetics to Education. In order to do so, John Dewey’s pragmatism will be placed in between somaesthetics and Education. Dewey played an essential part in the development of somaesthetics――not only its genealogy but also its fundamental concepts, for instance, “body”, “practice”, and “body consciousness”. Examining Shusterman’s understanding of Dewey’s pragmatism will help to clarify the pragmatic aspects of somaesthetics. To examine the possibility of extended understanding of somaesthetics for Education, the philosophy of physical education will be considered. Somaesthetics provides pragmatic viewpoints on the philosophy of physical education. From this viewpoint, the philosophy of physical education shauld be based on live somatic experience rather than on foundationalism.

著者

藤田 匡肖 勝田 叡 平田 欽逸 池田 隆二 山崎 正利 渡辺 功

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.10, no.2, pp.407, 1966-07-15 (Released:2016-12-31)

著者

大島 雄治 藤井 範久

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.1, pp.115-131, 2016 (Released:2016-06-17)

参考文献数

32

被引用文献数

2

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The purpose of this study was to clarify the function of torques exerted by the joints of the lower trunk during maximal velocity sprinting. Eight male track and field athletes volunteered, and sprinted 60 m from a standing start position. The ground reaction force of the support leg was determined using a force platform (1000 Hz), which was placed at the 50-m mark from the start position. Simultaneously, 3D coordinates were recorded with a motion analysis system (250 Hz) using 20 cameras (MX-T20). The joint torques were calculated using inverse dynamics. The contribution of joint torques to the right and left hip joint forces, and the torso joint force, was calculated by a method that simultaneously solves equations of motion for each segment and equations of constraint conditions for adjacent segments connected by a joint. The main results were as follows: (1) During the terminal support phase (80-100% normalized time), the angular velocity of anterior rotation of the pelvis decreased and participants in whom this angular velocity decrease was diminished ran faster (p<0.10). (2) During terminal support, the hip joint adduction torque of the support leg and the anterior rotation torque of the torso joint rotated the pelvis forward. The moment of the right and left hip joint forces rotated the pelvis backward. (3) During terminal support, the hip joint force of the support leg was generated by its hip joint flexion and adduction torque, the hip joint extension torque of the recovery leg, and the anterior rotation torque of the torso joint. In contrast, the hip joint force of the recovery leg was generated by the hip joint flexion and adduction torque of the support leg, and the anterior rotation torque of the torso joint. (4) During terminal support, the hip joint flexion torque exerted by the support leg rotated the pelvis backward. The hip joint adduction torque of the support leg and the anterior rotation torque of the torso joint rotated the pelvis forward. Previous studies showed that the hip flexion torque drives the leg forward from the hip joint extension position. This present study has clarified that the hip joint adduction torque of the support leg and the anterior rotation torque of the torso joint nullify backward rotation of the pelvis due to the hip joint flexion torque exerted by the support leg.

著者

伊藤 恵造 松村 和則

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.54, no.1, pp.77-88, 2009-06-30 (Released:2009-11-05)

参考文献数

58

被引用文献数

6 3

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Much attention is now being paid to the concept of “Community”. Not only in the field of urban sociology but also in the sociology of sport, “Community” is a key concept for understanding and resolving structural problems faced by both urban and rural residents.Discussions on the “public sphere of sport”, however, have run into deadlock when dealing with certain concrete structural problems. Furthermore, sports sociologists working on how sports practice can develop in communities have never been part of cumulative discussions in the field of urban sociology.The scope of studies on “Sport and Community” should involve a time-axis (historical-cultural) perspective to counterbalance the ideal and spatial frameworks. Apart from discussion on sport in relation to “human rights” and the “public good”, we must pay much attention to sites at which sport can create a new community by contributing to the resolution of structural problems. We will then be able to enter into a discussion on the “public sphere” created by sport practices.Urban sociology in Japan acknowledges sport as a medium that gives people a chance to meet each others in an urban setting. However, it has never been acknowledged as a public benefit that can contribute to creating an “autonomous community” for urban dwellers. We in the field of sports sociology should focus on places where people have tried to create “autonomous communities” through sports practices.

著者

木下 秀明

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.55, no.2, pp.409-440, 2010

被引用文献数

1

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In 1903, the Japanese Ministry of Military Affairs revised the manual of military gymnastics, the so-called <i>taiso kyohan</i>. In 1913, the Ministry of Education formulated the syllabus of gymnastics to be taught in schools, <i>gakko taiso kyojyu yomoku</i>. It has generally been considered that this syllabus was based mainly on the Swedish system of gymnastics. In the present study, I set out to clarify whether many of the gymnastic exercises performed on apparatus (except for hand-tools) as specified in the manual were designed for secondary school boys in the syllabus. The period studied was that from the time when the report <i>taiso yugi torishirabe hokoku</i>, meaning &ldquo;an investigation of gymnastics, play and games in schools&rdquo; was published in 1905 by the research committee authorized by the Ministry of Education, until the publication of the 1913 syllabus. The Ministry of Education had planned the syllabus in response to a demand from the Ministry of Military Affairs to formulate a school gymnastics program based on military lines, because the report had proposed the abolition of military gymnastics in schools. My research involved not only the use of general documents but also analysis and comparison of tables describing each phase of the exercises published in the manual, the report itself, and the syllabus, in order to verify relationships among them.<br> Based on the available materials, I concluded it was far from certain that there had been an insistence to include military gymnastics in school gymnastics, in spite of the fact that some military gymnastic exercises were listed in the report. Accordingly, the Ministry of Military Affairs had requested the Ministry of Education to devise a school gymnastics program based on military lines. &ldquo;Heaving movements&rdquo;, a component of the original Swedish gymnastics, which had been translated as <i>jyoshi no undo</i>, meaning &ldquo;arm-movements&rdquo;, was divided into two parts in the syllabus. One was <i>jyoshi no undo</i>, meaning &ldquo;arm-movements&rdquo;, except for exercises performed on apparatus, and the other was the new term, <i>kensui undo</i>, meaning &ldquo;chin-up movements&rdquo;, which literally covered a broad range of exercises including chin-ups and pull-ups on gym apparatus, because the two terms <i>kensui undo</i> and <i>cyoyaku undo</i>, meaning &ldquo;jumping and vaulting movements&rdquo;, were necessary in order for the syllabus to comply with the demand for military gymnastics. Military gymnastics was one of two main gymnastic systems in the syllabus, because the two partitions were composed of military gymnastics, as was the case for Swedish gymnastics.<br>

著者

豊嶋 陵司 桜井 伸二

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.2, pp.479-493, 2018-12-10 (Released:2018-12-20)

参考文献数

47

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This study investigated the relationships between the kinetic factor of the swing leg and step frequency (SF) and step length (SL) during the top speed phase of a sprint. Sixteen male sprinters (age 19.3±0.6 years, height 1.74±0.06 m, weight 66.1±5.2 kg) performed maximum effort 60-m sprints. Video data from the 43.5- to 50-m section of the sprint were collected using a high-speed camera (300 Hz). SF index and SL index were calculated to exclude the influence of body height on the outcomes of interest. Torque and torque power of the hip and knee joints of the right leg were calculated during the swing phase of the right leg. The time of the swing phase of the right leg was normalized so that the take-off of the right foot, touchdown of the left foot, take-off of the left foot, and touchdown of the right foot were 0%, 100%, 200%, and 300%, respectively. For every 5% of normalized time, partial correlation analysis was conducted between the right leg kinetics and SF index (controlling SL index) and SL index (controlling SF index). The SF index was associated with a large hip flexion torque and a large hip extension torque during 10–60% and 250–280% of the swing phase, respectively. Moreover, large peaks of the hip flexion torque and positive power were associated with a high SF index (r = -.718, p <0.01; r = .531, p <0.05, respectively). The SL index was associated with a hip flexion torque during 20–30% of the swing phase, although there was no significant partial correlation between the SL index and peak hip flexion torque (r = -.381, p = .161). In addition, a high SL index was associated with early appearance of the peak hip flexion torque power (r = -.759, p <0.01). In conclusion, throughout the top speed phase of a sprint, a high SF index requires a large torque and hip joint power for the leg swing over a short duration, and a high SL index requires an early increase of hip flexion torque power.

著者

小木曽 一之 串間 敦郎 安井 年文 青山 清英

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.41, no.6, pp.449-462, 1997-03-10 (Released:2017-09-27)

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The puropose of this study was twofold: (a) to investigate the pattern of change in the sprinting speed that is the final results of the sprinting movements, and (b) to find out whether the characteristics in the sprinting speed change due to the differences in age, sex, sprinting ability and training status. One-hundred thirty male and 123 female ordinary students aged 6 to 18, and 30 male and 23 female sprint runners aged 9, 10, 11 and 18 participated in this study. They were instructed to excute an exhaustive sprinting. Sprinting times ranged from about 20 to 30 sec. The elapsed times were measured every five meters in their sprinting. In the analysis, the polynomial curve fitting from 5th-degree to 9th-degree was used for the predictions of the sprinting distances with respect to the elapsed times every 0.1 sec. From the relations of the distances to times the following speeds were computed: 1) the sprinting speed that was computed by differentiating the sprinting distance, and 2) the average speed form start to the elapsed time every 0.1 sec. The sprinting speed reached the peak speed after about 6to 7 sec from start. The average speed showed the peak speed after about 15 sec from start. These characteristics with respect to time remained unchanged despite the differences in age, sex, sprinting performance and training status. The time at the maximum average speed was particularly stable. The maximum average speed was about 90% of the maximum sprinting speed. This result also remained unchanged despite the differences in age, sex, sprinting performance and training status,respectively. These results indicate that the pattern of change in the sprinting speed with respect to time is rather constant without the distinction of age, sex, sprinting performance and training status. The sprinting performance, however, improved with age and by training. This result was mostly caused by the increase of the maximum sprinting speed with age and by training. These characteristics with respect to time and speed seem to cause the differences in the sprinting distance.

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

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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

小宮 秀明 佐々木 絵未 黒川 修行

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.1, pp.29-42, 2016 (Released:2016-06-17)

参考文献数

19

被引用文献数

1

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High/low alcohol tolerance is determined by genetic polymorphisms of ADH2 and ALDH2. Currently, operators conduct ethanol patch testing for assessment of alcohol tolerance in a subjective manner; therefore, the test results may vary among individuals. The present study was designed to verify the reliability of ethanol patch testing, with a focus on changes in skin color due to seasons. Two operators were assigned to perform ethanol patch tests, and alcohol-related genetic polymorphisms were evaluated to verify the results.  The study included 129 healthy students from Utsunomiya University (age range: 21-24 years). These students were selected because they met the eligibility criteria for the study (all necessary information had to be available, i.e. results for all questionnaire items and patch tests, as well as genetic analysis). Alcohol-related genes tested in this study were ADH2 and ALDH2. During the ethanol patch tests, two operators examined the subjects' cutaneous reactions immediately after lint pad had been removed from their skin, and at 10 min after removal.  Ethanol patch test to the subjects was performed twice: once in summer and once in winter. We also administered a questionnaire to assess the students' views on alcohol and drinking habits. According to the cutaneous reactions examined at 10 min, there was significant concordance between the results of ethanol patch tests and ALDH2 genetic polymorphisms. The results of the patch tests performed by the 2 operators (A and B) in summer showed that the concordance rate between the operators was 93.8% (κ coefficient: 0.889; 95% confidence interval: 0.815-0.962, p<0.001) for the cutaneous reactions at 10 min after lint pad removal. Moreover, the same operator's data showed that the concordance rate between the results of the summer and winter patch tests was 70% or higher. These findings suggest that ethanol patch testing is a reliable assay of alcohol tolerance, although the results may be influenced by seasons and individual operator subjectivity. Therefore, during ethanol patch tests, it is important to take into account test conditions such as the time of year and skin color, and to evaluate the results comprehensively.

著者

図子 浩二 高松 薫

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.40, no.1, pp.29-39, 1995

被引用文献数

1 6

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Rebound drop jump index [RDJ_&ltindex&gt=(1/8・g・RDJt_a^2)/RDJt_c] was developed to evaluate the ability to perform the ballistic stretch. shortening cycle (SSC) movement. The RDJ_&ltindex&gt consists of ability to jump higher (RDJt_a) and that to shorten the contact time (RDJt_c) in rebound drop jump (RDJ), a typical SSC movement. The former is affected by leg strength and counter movement jump ability but the factors affecting the latter case have not yet been well established. This study examined the factors to shorten the contact time with special reference to two important views, i.e. work done by the lower limb joints and anticipation of the landing. 1. Relationships between work done by the lower limb joints and RDJ_&ltindex&gt, RDJt_c, and RDJt_a in RDJ from height of 0.3m were examined in ten college male athletes. There was a significant correlation between the ratio of negative work at the ankle to total work done by the lower limb joints and RDJ_&ltindex&gt (r=0.726, p&lt0.05), and RDJt_c (r=-0.823, p&lt0.01) but not RDJt_a (r=0.226,ns). Furthermore, there was no significant correlation between the ratio of negative work at the ankle and maximum plantar flexion strength (r=-0.329,ns). These results suggested that the rate of energy absorption at the ankle joint in former contact phase was one important factor to shorten the contact time in RDJ but not affected by plantar flexion strength. 2. RDJ_&ltindex&gt, RDJt_c and RDJt_a in two RDJs with or without visual information to inhibit temporal and spatial anticipation of landing were compared in six college male athletes. As compared without and with visual information, RDJt_c was longer, RDJt_a was shorter and RDJ_&ltindex&gt was lower, significantly. These changes were greater in subjects showing the higher RDJ_&ltindex&gt than those showing the lower RDJ_&ltindex&gt. Furthermore, changes of RDJ_&ltindex&gt, RDJt_c and RDJt_a in series of nine RDJs without visual information at thirty seconds of rest intervals were compared between subject A showing high RDJ_&ltindex&gt and subject B showing low RDJ_&ltindex&gt. RDJt_c decreased and RDJt_a increased slightly, and RDJ_&ltindex&gt increased by repeated trials even without visual information in subject A but not in subject B. These results suggested that temporal and spatial anticipation of the landing were another important factors to shorten the contact time in RDJ. These finding seemed to be beneficial for establishing strength and power training methods for jumper and ballgame players who are required ballistic stretch-shortening cycle movement.

著者

山元 康平 宮代 賢治 内藤 景 木越 清信 谷川 聡 大山卞 圭悟 宮下 憲 尾縣 貢

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.1, pp.159-173, 2014 (Released:2014-06-13)

参考文献数

39

被引用文献数

2

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This study was conducted to clarify the relationship between race pattern and performance in the men's 400-m race. Using several video cameras, 154 male 400-m sprinters (45-46 s: 26, 47 s: 35, 48 s: 58, 49 s: 35) in official competitions were videotaped at a sampling rate of 59.94 Hz from the start to the finish. The split time at every 50 m from the start was calculated using the Overlay method, which analyzes the split time by superimposing an image of the 400-m race onto an image of the hurdles in a 400-m hurdle race. Each segment was defined as follows: First segment, from the start to the 100-m mark; 2nd segment, from the 100-m mark to the 200-m mark; 3rd segment, from the 200-m mark to the 300-m mark; 4th segment, from the 300-m mark to the finish. The results of regression analysis revealed significant correlations between the 400-m race time and the all of the segment times (r=0.589-0.887, p<0.001), the ratio of the time for the 3rd segment (r=0.290, p<0.001) to that of the 4th segment (r=0.218, p<0.01), the rate of change in running speed from the 1st to the 2nd segments (r=−0.317, p<0.001), and that from the 2nd to the 3rd segments (r=−0.271, p<0.01). However, the relationship between the 400-m race time and the deceleration index (the slope of the linear relationship between running speed and the number of segments from the peak running speed to the finish) was not significant (r=0.154, p=0.056). These results suggest that it is important to maintain running speed in the 2nd and 3rd 100-m segments to achieve high performance in the 400-m sprint.