Taiikugaku kenkyu (Japan Journal of Physical Education, Health and Sport Sciences)
Online ISSN : 1881-7718
Print ISSN : 0484-6710
ISSN-L : 0484-6710
Volume 62 , Issue 2
Showing 1-23 articles out of 23 articles from the selected issue
Reviews
  • Toshiyuki Fujihara, Eito Yamamoto, Takafumi Fuchimoto
    2017 Volume 62 Issue 2 Pages 435-453
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: September 21, 2017
    JOURNALS FREE ACCESS
     In gymnastics, the vault run-up velocity is important from a competitive aspect. Relevant data in the literature have been relatively abundant but not well organized. The present review covers previous research on run-up velocity data and discusses its measurement for future research, as well as data utilization in practice. Based on the results of several representative studies, we can confidently state that a highly skilled male gymnast reaches a run-up velocity of over 8.5 m/s. At world-level competitions, the average run-up velocity is approximately 8.2 m/s for male gymnasts. Top-level female gymnasts also reach similar speeds. However, considering the issues related to the measurements used and the validity of the reported data, careful investigation is required, particularly with regard to the last step onto the springboard. We also discuss some difficulties with the use of current systems of velocity measurement, such as motion analysis, laser systems, and photocells, in daily training. In order for run-up velocity data to be measured and utilized in practice, (1) measurements should be performed easily, (2) the data should be more reliable and valid than a subjective evaluation by a coach or a gymnast, (3) feedback should be provided automatically and immediately, and (4) the measurement system should be reasonably affordable.
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Original investigations
  • Kei Tanisho, Hideo Ikarugi, Takuya Yano, Mitsuharu Kaya, Takashi Nagan ...
    2017 Volume 62 Issue 2 Pages 455-464
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: July 26, 2017
    JOURNALS FREE ACCESS
     A study was conducted to investigate the relationship between sprinting ability and agility using a longitudinal design. The subjects were 70 junior athletes (39 boys and 31 girls) aged 9 to 12 years participating in a Talent Identification and Development program. Physical constitution (height and body weight), 20-m sprint test time, rebound jump index, and ability to change direction (agility test and T-run test) were measured periodically for 3 years. The main results were as follows:
     1. Physical constitution, sprinting ability, rebound jump index, and ability to change direction increased significantly along with development in both boys and girls.
     2. Performances in the 20-m sprint, agility test, and T-run test in boys were significantly better than in girls, but no significant sex difference was observed in the rebound jump index.
     3. Single correlation analysis demonstrated significant correlations between all of the tests.
     4. Partial correlation analysis (using age in months as the control variable) revealed significant relationships between the agility test and T-run test in boys and girls, but correlations between 20-m sprint ability and the agility test or T-run test were not significant.
     5. There was little difference in the rebound jump index between boys and girls, and it was suggested that ability to change running direction was less affected by simple sprinting or strength-shortening cycle abilities during the developmental period.
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  • Kiyo Nakajima, Hideki Takagi
    2017 Volume 62 Issue 2 Pages 465-474
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: June 13, 2017
    JOURNALS FREE ACCESS
     By employing the Autonomous Posture Conversion Teaching (APCT) method, we attempted to improve the technique of immature swimmers in pushing off from the wall and gliding for a long distance. For this we conducted interventional experiments whereby the gliding distance during practice was continuously monitored, along with changes in subjective evaluation by the learner and observations of motion made by a third party. The participants were 14 college students (10 males, 4 females) majoring in sports science, all of whom submitted written consent to participate. The participants volunteered in 13 practice sessions focusing on pushing off and gliding from the pool wall using the APCT method. We conducted measurements at the beginning of the first practice, and at the end of the 5th, 10th and 13th practices. The results were compared between the practices and assessed from multidimensional aspects, including gliding distance, velocity, subjective experience by the participants, and observations made by third parties.
     It was found that the gliding distance and velocity increased progressively at each measurement point. One-way ANOVA revealed significant changes in the main effects after the intervention, including gliding distance and velocity, compared with those before the intervention. The subjective values and observation values also increased progressively with each measurement.
     In conclusion, when using the APCT method, it is preferable to conduct at least 5 practice sessions. It is important for immature swimmers to increase their wall contact time, and to ensure they use a stronger countermovement for pushing the wall.
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  • Shuji Kidokoro, Toshimasa Yanai
    2017 Volume 62 Issue 2 Pages 475-490
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: July 05, 2017
    JOURNALS FREE ACCESS
     The horizontal direction in which a batted ball travels is determined primarily by 2 factors: the horizontal angle of the bat at ball impact (first mechanism) and the interaction between the vertical inclination angle of the bat and the position of the ball impact along the short axis of the bat (second mechanism). As the bat is generally inclined vertically at the moment of ball impact (the head is positioned lower than the grip end), the second mechanism must cause an opposite influence on the horizontal trajectory of the batted ball when a grounder and a fly-ball are compared. The purposes of this study were two-fold: (a) to compare the contributions of the 2 mechanisms to the horizontal direction of batted balls between grounders and fly-balls and (b) to determine the relationship between the contribution of each mechanism and the speed of the batted ball. Sixteen collegiate baseball players were asked to hit balls delivered by a pitching machine aiming towards the same field and the opposite field for 4 trials each. The motions of the ball and the bat around the moment of ball impact were recorded using 2 high-speed cameras (1000 fps). The contributions of the 2 mechanisms to the horizontal directions of the batted balls were calculated from the following variables: the trajectory of the pitched and batted ball, projection angles of the bat in the horizontal plane (horizontal bat angle) and the vertical plane (vertical bat angle), and the angle of the line of impact from the horizontal at ball impact (line of impact angle). The first mechanism contributed 40% or more on average to both the same- and opposite-field hitting of grounders and fly-balls projected towards the fair territory. For fly-balls to the same field and grounders to the opposite field, the contribution of the first mechanism was particularly high (same/fly ball: 118.6±35.2%, opposite/grounder: 109.5±17.8%), and the impact surface of the bat faced toward the batted ball direction. The contribution of the second mechanism was greater for grounders to the same field and fly-balls to the opposite field than the others (same/grounder: 46.7±23.3%, opposite/fly ball: 50.6±49.2%). The speed of the batted ball was negatively correlated with the contribution of the second mechanism (r=−0.73, p<0.01). Therefore, in order to hit a ball with higher speed, a batter should adjust the timing of impact to use the first mechanism, and should strike near the center of the ball.
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  • Mitsuru Kurosu, Hiroshi Mizukami
    2017 Volume 62 Issue 2 Pages 491-510
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: June 26, 2017
    JOURNALS FREE ACCESS
     The purpose of this research was to clarify the importance of the complementary relationship between the Japan Sports Association (JASA) and an Information Network Support NPO (NPO) for creation of a public sphere based on the main arguments of Albert Melucci in his theory of new social movements and Ernesto Laclau and Chantal Mouffe in their theory of radical democracy. For this, the JASA (a private sporting organization that plays a central role in the field of Japanese sports) and the NPO (an external organization that has supported the development of community sports clubs [CSCs]) were regarded as civil society organizations that are independent of the public and private sectors, in order to comprehend the complementary relationship between the 2 in real terms.
     Data on the actual practices of the JASA and the NPO between 1997 and 2007 were analyzed, and the complementary relationship between the 2 organizations was then discussed based on the concepts of mobilization and symbolic movement. Mobilization is a social space in which individuals redefine their social roles in a self-recursive manner through acceptance of information resources related to the values and ideals that society requires. Symbolic movement is a generic term for social movements whereby individuals' voluntary discourse act and associations act are transformed into civil society-based public intention.
     As a result, it was clarified that the JASA has been facilitating mobilization that can temporarily remove individuals from public bureaucracy and customs and direct them towards parties related to CSCs through announcements of investigation and research results and lifelong sports vision and recommendations. On the other hand, it was revealed that the NPO has been playing a symbolic role, leading to normative discourse act and associations act that are initiated by various individuals who are interested in CSCs, namely the private sector, through interactive information exchange that leverages the information and telecommunications infrastructure. Although the business methods of these 2 civil society organizations seem to be confrontational when viewed from the perspective of a complementary relationship, it was suggested that creative confrontation between mobilization and symbolic movement is a requirement for creation of a public sphere. Furthermore, the complementary relationship between mobilization and symbolic movement that attempts to aggregate and share various sources of information related to CSCs, showed some degree of ambiguity, and accordingly may be transformed into public intention in the form of collective/political action.
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  • Kei Ogura, Takashi Kawamura, Tetsuya Kanahori, Takaki Nomoto, Yoshiki ...
    2017 Volume 62 Issue 2 Pages 511-522
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: June 21, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to clarify the types of step adjustment performed by baseball infielders for catching a grounder in relation to skill level. The subjects were 18 amateur baseball infielders, whose fielding motions were videotaped using 2 high-speed video cameras (300 Hz). The 3-dimensional coordinates of both the toes and the ball were obtained using the DLT method. The top 9 subjects who showed small variations in the grounding point of both feet when adopting the catching posture were defined as a high-performance group, and the bottom 9 subjects were defined as an intermediate-performance group. The results obtained were as follows:
     1) Baseball infielders modified each grounding point from 4 steps to 1 step before catching in order to acquire the most appropriate catching point, and the final step was highly reproducible.
     2) The high-performance group showed a significantly smaller standard deviation in the 1 step before the grounding point than the intermediate-performance group.
     3) In the high-performance group, there was a positive correlation between the standard deviation of step length 1 step before and the standard deviation of the grounding point from 5 steps to 2 steps before.
     These results suggest it is important to reduce variations in the grounding point 1 step before by earlier perception of the error in the front-to-rear direction of the grounding point. These results could provide important insight for coaches or trainers attempting to improve the performance of infielders when catching a grounder.
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  • Fumiya Tanji, Yasushi Enomoto, Yoshiharu Nabekura
    2017 Volume 62 Issue 2 Pages 523-534
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: July 25, 2017
    JOURNALS FREE ACCESS
     This study investigated the relationships between running economy and various step parameters (ground contact time, step length and step frequency), as well as the effects of these relationships on differences in foot strike pattern at intensities ranging from below to above the lactate threshold in well-trained distance runners. Thirty-one male distance runners (20 middle-distance and 11 long-distance; age 19.5±1.2 years, height 171.7±4.5 cm, mass 57.6±3.5 kg, BMI 19.5±0.7) participated. Their seasonal best performance was 804.0±121.0 points, expressed as the IAAF score. Both running economy and step parameters were calculated for speeds of 15.0, 16.2 and 17.4 km·h−1, which corresponded to intensities below, equivalent to and above the lactate threshold, i.e. 93.2%±6.4%, 100.6%±6.9% and 108.1%±7.4%, respectively. As running speed increased, running economy, step length and step frequency increased, whereas the ground contact time decreased. A significant positive relationship was observed between ground contact time and running economy at an intensity above the lactate threshold (r=0.46, p<0.01). A significant positive relationship was observed between step length and running economy (r=0.54 and 0.52, p<0.01), and a negative relationship was observed between step frequency and running economy (r=−0.55 and −0.53, p<0.01) at intensities equivalent to and above the lactate threshold, respectively. Middle-foot strikers exhibited a shorter ground contact time than rear-foot strikers at intensities equivalent to and above the lactate threshold, whereas running economy exhibited no significant difference in terms of foot strike pattern. From the present results, it can be concluded that a shorter ground contact time enhances running economy; however, running economy is not related to the foot strike pattern at an intensity of 90%—110% of the lactate threshold.
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  • Satoru Tanabe, Takayuki Seto, Koichi Kawabata, Masatoshi Murakami
    2017 Volume 62 Issue 2 Pages 535-558
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: August 31, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to clarify differences in the joint movements of skilled and unskilled players during basketball three-point shots. 30 male collegiate basketball players (skilled players) and 30 male college students who did not technically play basketball (unskilled players) participated. The three-dimensional coordinates of reflective markers attached to the subjects and the basketball while performing three-point shots were obtained using a motion capture system with 22 cameras (250 fps). The findings are summarized as follows.
     1) The height of the ball at release was significantly greater for the skilled players than for the unskilled players. However, the initial ball velocity and angle of ball projection were significantly greater for the unskilled players than for the skilled players.
     2) Both the skilled and unskilled players produced large angular velocities of elbow extension, which resulted in high ball velocities. However, the movements of skilled players were more efficient, generating higher ball velocities with smaller angular velocities.
     3) While both the skilled and unskilled players used wrist palmar flexion and finger movement to accelerate the ball, the unskilled players used significantly more wrist palmar flexion, whereas the skilled players used significantly more finger movement to produce the ball velocities.
     4) Shoulder abduction and finger movement worked to develop the vertical ball velocity to maintain the appropriate angle of ball projection.
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  • Kazumichi Ae, Sekiya Koike, Norihisa Fujii, Michiyoshi Ae, Takashi Kaw ...
    2017 Volume 62 Issue 2 Pages 559-574
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: September 01, 2017
    JOURNALS FREE ACCESS
     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.
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  • Gen Horiuchi, Hirotaka Nakashima, Shinji Sakurai
    2017 Volume 62 Issue 2 Pages 575-586
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: August 25, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to evaluate the generation, absorption and transfer of mechanical energy during baseball batting, focusing on the lower extremities and torso. The batting motion and ground reaction forces acting on each foot of 79 amateur baseball players were recorded using a motion capture system and 2 force plates. The joint forces and joint torques were calculated using inverse dynamics. In addition, the mechanical powers as a function of each joint torque were calculated to assess the generation/absorption of mechanical energy. The mechanical powers as a function of joint forces and joint torques acting on each segment were calculated to assess the transfer of mechanical energy. The main results were as follows:
     1. In the phase from contact of the stride foot to the peak lower torso rotational velocity (lower torso acceleration phase), the mechanical energy was generated and flowed into the lower torso as a function of hip joint torque.
     2. In the lower torso acceleration phase, the mechanical energy flowed out from the lower torso to the upper torso as a function of torso joint torque.
     3. In the phase from the peak lower torso rotational velocity to impact (swing phase), the mechanical energy was generated and flowed into the upper torso as a function of torso joint torque.
     4. In the swing phase, the mechanical energy of the bat increased rapidly, and this amount of change was significantly correlated with the bat head speed at impact.
     5. Though the analysis phase, the change in the mechanical energy of the torso was small.
     These results suggest that both hip joints generate mechanical energy and that the torso acts as a pathway of mechanical energy during baseball batting. In addition, the transfer of mechanical energy from the torso to the upper extremities and the bat contributes to increasing the bat head speed at impact.
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  • Kosuke Yano, Shunsuke Kimura, Kazuo Oishi
    2017 Volume 62 Issue 2 Pages 587-598
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: August 30, 2017
    JOURNALS FREE ACCESS
     Previous studies have shown that a high level of sensory-processing sensitivity (SPS) could be a risk factor for mental health. Many studies have reported that daily exercise helps to retain and/or improve mental health. This study examined the relationship between the level of daily exercise and SPS among university students. The participants were 292 university students (143 males and 149 females) ranging in age from 18 to 23 years (19.4±1.1 years). They were asked to complete a questionnaire that included the following items: 1) the frequency of exercise (days per week), 2) the number of years of successive daily exercise, 3) the sporting events in which they currently participate, and 4) the Japanese version of the 19-item Highly Sensitive Person Scale (HSPS-J19) including 3 sub-scales, i.e., low sensory threshold (LST), ease of excitation (EOE), and aesthetic sensitivity (AES). The participants were categorized into a) high, b) medium, and c) low frequency groups, or a) short, b) middle, and c) long term groups individually, based on their levels of participation. Additionally, they were categorized into a) individual, b) team and high-frequency physical contact (HC), and c) team and low-frequency physical contact (LC) exercise groups based on their exercise habits. The high frequency and long-term groups showed lower scores of the HSPS-J19 and its sub-scales of LST, EOE, and AES than the other groups. No significant differences were found among the groups with regard to sports currently played in the scores of the HSPS-J19 and its sub-scales, i.e., LST and EOE. Only AES scores in the LC groups were higher than those in the HC groups. These results suggest that the appearance of SPS was moderated as a result of high-frequency and/or the long-term daily exercise due to habituation to strong stimuli.
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  • Yuta Ono, Hidenori Tomozoe, So Nemoto
    2017 Volume 62 Issue 2 Pages 599-620
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: September 27, 2017
    JOURNALS FREE ACCESS
     In recent years, the way university sports are conducted has been under discussion. In particular, there is some concern about the balance between studies and competitive activities, which is important when considering the future of university sports in Japan. As no previous research has focused on sports recommendation admissions to universities in Japan, the present study first attempted to clarify the way in which this system has developed.
     The following findings were obtained:
     1. In Japan, even before the recommendation admission system was officially approved, athletes had been given preferential treatment in entrance examinations, which was not disclosed to the public or stipulated in application guides.
     2. Soon after the recommendation admission system was officially approved, campus disputes worsened, which caused the preferential admission treatment of athletes to be severely criticized, making it difficult to continue with the conventional system any longer. Accordingly, during the period from the late 1960s to the early 1970s, universities abolished the preferential treatment given to athletes in entrance examinations.
     3. Since the recommendation admission system was officially approved in 1967, the faculties of physical education at private universities, among others, started to actively admit athletes based on recommendation. These physical education faculties selected students based on physical skill tests to secure competent athletes. Thus, by matching the admission policy of the faculty with the sporting abilities of athletes, universities were able to secure competent athletes without having to impose a special admission quota for athletes.
     4. In the 1980s, private universities played a leading role in conducting entrance examinations with a special admission quota for athletes. Waseda University launched the Special Selection System for Physical Education Major, which introduced a special admission quota for athletes, specified the athletic events and performances, and made the selection process widely known to the public. In conducting this selection, however, the university faced a dilemma of whether or not to employ it as the system for strengthening their sports teams.
     5. In 1987, the Ad Hoc Council on Education, an advisory body of the Japanese Government on education, recommended that assessment of sports activities be taken into consideration in entrance examinations. The 1989, the Guidelines for University Entrance Examination, revised in accordance with the Council's recommendation, listed “adequate assessment of activities in sports, culture, etc.” as a selection method for university admission for the first time.
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  • Hideya Nakatsuka, Ayaka Ieyoshi, Yukinori Takeda, Norihide Yamashita, ...
    2017 Volume 62 Issue 2 Pages 621-629
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 20, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to determine the relationship between endurance running performance and aerobic capacity (maximal oxygen uptake: VO2max, velocity at ventilatory threshold: vVT, running economy: RE) in elementary school boys, in relation to their development and height growth. Ninety-three healthy elementary school boys participated. Endurance running performance was evaluated in terms of running velocity at VO2max (vVO2max), which was measured by an incremental running test on a treadmill. VO2max, vVT and RE were also measured in the same way. It was found that vVO2max was significantly related to VO2max, vVT and RE. Chronological age was significantly related to absolute VO2max (L·min−1), vVT and RE but not relative VO2max (mL·kg−1·min−1). Among developmental factors, chronological age was significantly related to VO2max, vVT and RE, but not VO2max. Therefore, we conclude that the factors contributing to improved endurance performance of elementary school boys are VO2max, vVT and RE. With regard to development and related height growth, endurance performance could be attributable to vVT and RE (i.e. qualitative changes) rather than VO2max (i.e. a quantitative change).
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  • Gen Tanabe
    2017 Volume 62 Issue 2 Pages 631-646
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 30, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to clarify the handing down of a martial art in a Japanese village community, focusing as an example on the Shinto Katori-Ryu School.
     The Shinto Katori-Ryu School was established in Kamigawara from the mid Edo period. Kamigawara was a farm village, and the members of the school were farmers. The Shinto Katori-ryu School was characterized by the following features.
     1. There was no specific master exponent at the school, and the coaching was done by the village elders. Generally, at most Japanese martial art schools, a magnate or an authority acted as a master.
     2. Only the eldest sons of the village were coached, and were referred to as sozokunin, meaning “heirs”. Learners at other schools are usually referred to as “pupils”, but this was not the case here. In order to become a sozokunin, a rite of passage known as kenjyutsu denjyu was necessary.
     3. The school taught not only kenjutsu, but also methods of treating plague, and was dedicated to the god of a shrine. In addition, details of village regulation were also taught.
     The Shinto Katori-ryu School was closely related to village affairs, and was aimed at educating people within the village. In this way it was recognized as a “folk movement” unique to Kamigawara. After the Meiji era, the school traditions were handed down until World War 2, while maintaining the relations close to local society. Therefore, after the modern era, it was not assimilated by budo and kobudo. Later, like many folk customs, the tradition was swept aside during the period of rapid economic growth.
     The organization of a martial art has generally been understood as adhering to the iemoto system. However, the organization of the Shinto Katori-ryu School took a different form, and is one example of a martial art that was nurtured and handed down by farmers.
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  • Saburo Nishimura, Yoshinori Kinomura, Yasuto Kobayashi, Rei Matsuzaki, ...
    2017 Volume 62 Issue 2 Pages 647-663
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 12, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to determine whether physical education lessons focusing on the long jump for elementary school fifth graders would be able to improve their vertical jump velocity. Twenty-eight elementary school fifth graders were instructed in the long jump over 5 lessons. To gain a higher vertical velocity, participants were instructed to pull their swing legs forward at the moment of touchdown and to lean their trunks backward during the jump. Measurements were taken during the first and fifth lessons. To evaluate the jumping motion, the body's center of gravity and segment angles were obtained using a high-speed video camera from a side angle.
     The main results were as follows:
     1) Since vertical velocity at takeoff and jumping distance were both significantly increased, elementary school fifth graders were able to learn to gain a higher vertical velocity. However, the increase in jumping distance was not due to the increase in vertical velocity but rather a decrease in the distance lost during landing.
     2) Although post-measurement showed that the swing legs at touchdown were pulled more forward than at pre-measurement, the change in that motion did not contribute to the increased vertical velocity.
     3) At post-measurement, the trunk was inclined more backward than at pre-measurement. Therefore, forward rotation of the body was suppressed at takeoff, which increased the vertical velocity. In addition, suppressing the forward rotation of the body strongly contributed to the decrease in distance lost during landing.
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  • Hirokazu Matsuo, Yukio Yamada, Katsuyuki Masuchi, Tsuyoshi Matsumoto
    2017 Volume 62 Issue 2 Pages 665-677
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 24, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to verify the effectiveness of the Heads Up Tackling program for defensive players and its influence on safety and performance. Head impacts in football players are directly associated with brain and spine injury, and have been proposed to be associated with injuries such as chronic traumatic encephalopathy (CTE). Therefore, improvement of safety has been a challenge in American football, from the perspective of injury prevention. In 2012, USA Football, the national governing body for amateur American football in the USA developed the Heads Up Football (HUF) program which included “Heads Up Tackling” (HUT), a set of new guidelines for tackling. HUT has been attracting attention in the context of safe tackling through a new coaching methodology. Although in Japan so far, there have been no reports of football-related chronic injuries caused by head impacts, many concussions occur in football games. Therefore, it seem necessary to identify a methodology for teaching tackling techniques in order to reduce the risks of head and neck injury. A number of studies have focused on coaching intervention in relation to safety, and for reducing head impact exposure and injury. However, no reports have focused on the impact of these efforts on athletic performance during a game. If it could be confirmed that HUT reduces the risk of injury in football games without decreasing athlete performances, it would be a useful resource for instruction on tackling skills. Here, 4 matches in the Japan top league (X-league) 2014 and 2015 season were analyzed, before and after HUT intervention was executed in the preseason of 2015. A total of 166 coded tackles were compared in terms of “tackling characteristics”, “amount of injuries”, “effectiveness of tackling”, and “loss of yards” to examine the effect of HUT techniques on “safety” and “effectiveness”. The results revealed that (1) the frequency of “head down” tackling was significantly lower after HUT intervention, (2) the “amount of injuries” was reduced after HUT intervention, (3) there was no effect on the “effectiveness of tackling” in games, (4) “loss of yards” was reduced after HUT intervention, and (5) HUT appeared to reduce the risks of injury in football games, without decreasing tackling performance.
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  • Kazushige Oshita, Takuya Matsuzaki, Akihisa Hikita, Ryo Miyazaki, Goic ...
    2017 Volume 62 Issue 2 Pages 679-690
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: November 09, 2017
    JOURNALS FREE ACCESS
     By means of a questionnaire-based survey, the aim of the present study was to investigate body part(s) training consciousness in young people (n=1000) through imaging of trunk muscle exercises. The participants were shown pictures of the bent-knee sit-up (sit-up), back extension (back-EXT), and elbows-to-toes plank (plank), and then asked which body part(s) they felt was being trained in each picture. Only 3% and 8% of the participants had never performed the sit-up and plank exercises, respectively. On seeing the images, 40—60% of the participants who had no experience doing a sit-up or back-EXT felt that these exercises were to train not only the agonist muscle but also the antagonist muscle. Approximately 40% of the participants who had no experience doing the plank exercise felt that it was not to train the epigastrium or hypogastrium area. Among the participants who had experienced the plank exercise without any previous experience of strength training under professional supervision, more than half felt that the plank exercise was appropriate for training not only the trunk but also the upper limb or lower leg. Furthermore, among the participants with previous experience of strength training under professional supervision, approximately 30% had such an opinion. Therefore, although the penetration rate of these trunk exercises is high, merely performing them by reference to only a picture may result in the participants not properly understanding how the body part(s) should be trained during the exercise. Therefore, to enhance the benefits of trunk exercises, individuals (even those who have had previous experience of training under professional supervision) always need to receive appropriate supervision on the correct technique and to acquire knowledge about the exercises.
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  • Yuta Funato, Shinji Sakurai
    2017 Volume 62 Issue 2 Pages 691-703
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: November 02, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to identify the relationship between take-off motion and jump distance in medium-hill ski jumping. The subjects were 21 ski jumpers (16 males and 5 females, height: 1.65±0.09 m, weight: 54.6±8.9 kg, age: 19.2±6.8 yr) whose take-off phase on a medium-hill (hill size: 68 m) was filmed with 2 synchronized high-speed video cameras (200 Hz). The take-off motion was analyzed 2-dimensionally in the sagittal plane. The results were as follows:
     1) The approach velocity and vertical velocity of the jumper's center of gravity at the instant of release were found to be significantly correlated with jump distance (r=0.768, p<0.01; r=0.775, p<0.01), suggesting that these 2 parameters are as important for medium-hill as for normal-hill ski jumping.
     2) Ski jumpers increased their jump distance by moving their trunk forward with knee joint extension during take-off and by reducing the trunk angle at the instant of release from an initial position in which the lower limb joints were deeply flexed.
     3) Stepwise multiple regression analysis showed that (1) the hip angle at the initial position, (2) the knee joint angular velocity at the instant of release, and (3) the horizontal velocity of the trunk relative to the feet at the instant of release were the 3 significant factors, accounting for 82.3% of the jump distance. The importance of knee joint angular velocity at the instant of release has increased following the recent changes in ski jumping technique and regulations.
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  • Yuzo Nakase, Atsushi Sano
    2017 Volume 62 Issue 2 Pages 705-721
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 19, 2017
    JOURNALS FREE ACCESS
     The purpose of this research was to clarify the structure of the momentum of basketball games as sensed by point guard players with excellent ability from the “Bewegungslehre des Sports” viewpoint in order to improve the tactical ability of basketball players. The study involved an interview survey of 3 such players. After considering the structure or the momentum of games, the following points became clear.
     1. The players are aware that “continuity” and “compulsion” form the nature of game momentum. These 2 characteristics are seen as both Good and Bad momentum.
     2. “Player's feelings” were listed as one of the facets of game momentum. As a means of optimizing such feelings, priority was given to player encouragement and selection of tactics to make the game exciting.
     3. “Play based on common tactical intention” was listed as another facet of game momentum. Games developed with such intention had the strongest possibility of winning, and the players considered that practicing it (or preventing the other team from doing so) without any difference in tactical intention created momentum.
     4. “Player's feelings” and “play based on common tactical intention”, which contribute to momentum, were considered to be not independent but interactive.
     5. As a result, it was clarified that “players' feelings” is a factor that can directly generate “game momentum” and that “game-related events” and “player's sense of value” are factors that can influence each other and are interdependently structured.
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Practical investigations
  • Yohei Yoshida, Ikuro Fujita
    2017 Volume 62 Issue 2 Pages 723-737
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: August 10, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to clarify changes in high jump (scissors jump) performance in physical education classes for junior high school students in order to suggest training optimization according to grade. High jump lessons were conducted 8 times, and the scissors jump motions of the subjects were captured by 2 cameras (60 fps), both fixed and panned, in the first (pretest) and last (posttest) classes. The motions of the subjects were analyzed in 3 dimensions using the panning DLT method. The subjects were 22 students who were divided into 2 groups: 1st and 2nd grade students who learned the high jump as a compulsory subject, and 3rd grade students who did so as an optional subject.
     The main results were as follows: (1) In both groups, whereas the mean approach run speed was significantly decreased, the best records were significantly improved. (2) In 1st and 2nd grade students, the change in the ankle joint angle of the take-off leg during the take-off phase was smaller in the posttest than in the pretest. In addition, the knee joints of both legs during the jumping phase were more extended in the posttest than in the pretest. (3) In 3rd grade students, the take-off angle was significantly increased, and moreover the rate of conversion of the horizontal velocity of the center of body mass (COM) at the start of the take-off phase into the COM vertical velocity at take-off was significantly increased. This increase in the conversion rate was related to a significant increase in the knee extension velocity of the take-off leg during the take-off movement. In 3rd grade students, a more pronounced rhythm was observed in the last 2 steps of the approach run during the posttest.
     From these results, we suggest that for 1st and 2nd grade students, emphasis should be placed on the technique for obtaining rhythm in the approach run, whereas for 3rd grade students, there should be a focus on the take-off movement, making good use of the approach run speed.
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  • Hiroshi Nakanishi, Seiichiro Kihara, Kazuki Osedo, Kenji Kubo
    2017 Volume 62 Issue 2 Pages 739-755
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 25, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to develop effective plans for teaching students to “spring” by building lesson plans adopted the “forward roll bridge” (FRB) and analyzing the effectiveness of the lesson plans through their execution in classes.
     Lessons in “spring motion from a higher level” (SMH), which were taught over 6 school hours in total, were conducted as part of the apparatus gymnastics unit in the period April 15—28th, 2016. The participants were 5th grade students (32 male, 31 female, 2 classes) at “F” elementary school, located in Hiroshima prefecture. These lessons were followed by the FRB lessons (10 school hours in total) developed for this study, in which the students learned the “spring motion with hip subduction, from a forward roll” (SHF), with the aim of accomplishing the SMH by landing on the ground. This elementary school employs a subject teacher system for all grades, and the students had already learned the “antenna bridge” (AB) and the FRB in the previous year.
     The results of this study were as follows:
     (1) An improvement of the students' athletic skills when performing the AB, FRB, and SMH moves was observed after the 6 school hour lessons. This confirmed that the lesson plans were effective for teaching SMH.
     (2) A correlation between achieving FRB and SMH was found in the first lesson (|r|≦0.700, p<0.0001), suggesting that FRB should be learned before SMH for a higher achievement rate. After the 6th lesson, correlations between AB and FRB (|r|≦0.348, p<0.006) and between FRB and SMH (|r|≦0.440, p<0.0001) were found. This suggested that FRB was an effective move for connecting acquisition of AB and that of SMH.
     (3) Qualitative analysis of the students' movements indicated that there were 2 types of students who were unable to perform SMH: those who achieved SHF but could not do the spring, and those who could not achieve SHF. This differs from former studies that highlighted only the latter type of students. Therefore, it appears that the main difficulties of SMH are that students 1) need to achieve 2 skills, SHF and “pushing with hands,” and 2) need to adapt themselves to another situation in order to be able to accomplish the move.
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Materials
  • Ikuro Fujita
    2017 Volume 62 Issue 2 Pages 757-771
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: August 30, 2017
    JOURNALS FREE ACCESS
     The purpose of this study was to examine the effectiveness of a strategy focused on the development of teaching materials in teaching trials conducted as part of the “Seminar in Methods of Teaching Physical Education” course. In the academic year 2012, such teaching trials were designed to promote the course participants' awareness of “teaching materials” and “subject matter”. As a means of promoting such awareness, participants were assigned new tasks to develop supplementary teaching materials. The reactions of the participants to the trial teaching sessions in 2012 were analyzed and compared with those for 2011. The main findings were as follows:
     1) Many of the participants' reactions centered on the fact that the “teaching materials” employed in the first trial did not lead to an improvement in teaching technique.
     2) The participants' reactions tended to focus on 2 aspects: “the appropriateness of teaching materials as subject matter” and “the systematic connection of supplementary teaching materials as unit teaching materials”.
     These results indicated that the strategy used in this study to develop supplementary teaching materials and video observations of the trial teaching sessions were effective for making participants aware of the concepts of “teaching materials” and “subject matter” and the relationship between the 2 from the earlier period of the course.
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  • Eiji Ito, Tom Hinch
    2017 Volume 62 Issue 2 Pages 773-787
    Published: 2017
    Released: December 19, 2017
    [Advance publication] Released: October 19, 2017
    JOURNALS FREE ACCESS
     Japan is scheduled to host 3 major international sporting events during the next 4 years: the 2019 Rugby World Cup, the 2020 Tokyo Olympics and Paralympics, and the 2021 Kansai World Masters Games. The prospect of these events provides a strong incentive for sport tourism research in Japan; however, it is more important to ensure that this scholarly effort is sustained after the sporting events take place. It is also important to build on and integrate existing knowledge in the fields of sport sciences and tourism. It is important to grasp the state of sport tourism knowledge in Japan, and one way of doing this is to conduct a systematic review. Therefore, the purposes of this research note are to: (a) review sport tourism research articles published in Japanese journals; (b) identify trends in research methods and thematic patterns; and (c) discuss avenues for future research. For our systematic review, we used 2 major academic search engines, CiNii (Articles) and J-Stage, to identify articles on sport tourism research published in Japanese journals. The following combinations of keywords were used to drive the search: (a) “sport” and “tourism” and (b) “sport” and “kankou” (i.e., a Japanese word used broadly to mean “tourism”). This resulted in the identification of 52 sport tourism research articles that included “sport” and “tourism” (or kankou) in their title, abstract, keywords, or journal name. More than half of the articles (63.5%: n=33) were published in the 2010s. The majority of sport tourism articles focused on active sport tourism (32.7%: n=17) and participant-based sport events (30.8%: n=16). The vast majority of the articles (78.8%: n=41) were empirical in nature, 19.2% (n=10) being literature reviews and 1.9% (n=1) being conceptual. Among the empirical research articles, case studies (43.9%: n=18) and questionnaire surveys (39.0%: n=16) were frequently employed. The majority of the sport tourism articles addressed social and cultural themes (71.2%: n=37), followed by economic themes (13.5%: n=7), whereas fewer articles were related to environmental themes (9.6%: n=5). While accumulation of additional knowledge about the major international sporting events scheduled for Japan remains crucial, our systematic review indicated that future research should also address gaps related to: heritage sport tourism, qualitative methodologies, cross-cultural/national approaches, environmental topics, and theory-driven research. Integration of interdisciplinary knowledge in tourism, sport, and other related studies will help to encourage sustainable sport tourism development after the events have been held.
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