This study delineates the common characteristics of pitching motion in professional baseball pitchers by focusing on their lower limbs. Further, to gain an insight into the development of athletic capacity, the pitching motion of the Top group was compared with the Minor group, resulting in the clarification of lower limb issues in the Minor group. Data analysis was performed using a test with the highest score in a 5-point objective evaluation by the observer and the highest ball speed in the tracking data obtained from Trackman, with the following results: (1) The common characteristics in a professional baseball pitcher was that the hip joint was flexed while the stride leg knee joint angle was fixed to MBV (Minimum Ball Velocity), MER (Maximal Shoulder External Rotation), and the stride leg hip joint and knee joint were slightly extended to MER, REL (Ball Release). (2) Regarding the difference between the Top and Minor groups, it is suggested that the Top group accelerates the rotational speed of the lower torso to SFC (Stride Foot Contacts Ground), which increases the angular velocity of adduction of the hip joint of the stride leg, resulting in torsion of the trunk and stable force transmission after MBV. (3) In the Top group after SFC, the angular displacement and angular velocity was such that the hip joints of both legs were fixed. Additionally, the stride leg hip joint was in adduction, which caused the motion to increase the rotation of the lower and upper torsos. Authors suggest considering these key points while coaching baseball.

    This study investigated effects of the immediate feedback training on the improvement in the skeleton starting motion using a motion model for coaching. The motion model for coaching the skeleton starting motion was created from the motion data of eleven excellent male athletes who participated in the Intercontinental and Europe Cups in 2018. In the immediate feedback training of an hour with the push skeleton, in which six participants attempted, a video delayed playback system was used to compare the participants' starting motion with the motion model. The starting motions of the pre- and post-immediate feedback training were recorded with two video cameras, and participants' motive consciousness and motion image of the starting motion were collected with a questionnaire method.
    The step length of the 1st step (p＝0.046) was significantly increased after the immediate feedback training. The motion deviation as an index of the change in the starting motion decreased in the hip and shoulder joints, but that of the left ankle joint increased. The motive consciousness and motion image of critical points differed among the athletes and a coach, but were able to be shared and exchanged among them during the immediate feedback training with the help of the motion model. These results indicated that the immediate feedback training using the motion model was effective in improving the skeleton starting motions, as well as the motive consciousness on the critical points.

    The values toward the elements and techniques of gymnastics are not permanent. Various influences cause these values to change over time. To better understand the elements and techniques of today, it is necessary to comprehend how such values have changed over time, and such comprehension is possible only through deep insight into the history of the development of the elements and techniques.
    However, there is a lack of research on the historical changes of gymnastic elements and techniques. Research on some apparatuses and periods has not even begun. For this reason, much of the history of the recognition of skills and the development of techniques is yet to be organized and elucidated.
    Morii and Watanabe (2019) focused on the technical development of the salto in male floor exercises from the 1970s to the 1980s. Therefore, to cover a portion of the history of technical development in gymnastics that has yet to be sufficiently studied, this study examined the development tendency of the salto and their factors in menʼs floor exercise taking place since the 1990s.
    The conclusions were as follows:
    1. This study was able to sort the previously unorganized history of the development of the salto since the 1990s.
    2. The study clarified that a wide variety of skill combinations have emerged since the 1990s. The trends of such emergences have been significantly influenced by the code of points in each period.
    3. This study confirmed that the introduction of the spring floor expanded the possibilities of technical development, leading to significant progress in the development of salto.
    The results of this study will inform the appropriate evaluation of current elements and techniques of floor exercise. These results will also enlighten the future development of gymnastic elements and techniques while providing practical guidance for efficient coaching.

    Measuring foot pressure during exercise is effective for improving competitiveness and preventing injuries in the field. The purpose of this study was to clarify the characteristics of the data collected by an insole type smart device and to examine whether it is effective for evaluating the sole pressure during exercise. The position of the pressure sensor inside the insole device was measured by X-ray CT imaging. Image data on the application was recorded when a load was applied to each sensor. Furthermore, the center of pressure of front and rear and left and right were compared with the data on the force plate. As a result, (1) the four sensors are arranged under the distal phalanx of the second toe, the first metatarsal head, the fifth metatarsal head and the calcaneus. (2) Image data changes from light green to green, yellow, orange, and red according with increasing pressure and did not change at more than 142 kpa. (3) The center of pressure on anterior-posterior and left-right foot could be measured correctly. These results suggest that the insole type smart device is effective for the evaluation of plantar pressure during exercise. The findings of this study contribute to the utilization of data at the competition field.

    It is generally recognized that weight gain leads to performance decrement in female long jumpers. However, the problem in weight control, the relationship between weight and performance, and the factors affecting weight change remains unclear. To reveal these problems and obtain the useful knowledge for coaching on weight control of female long jumpers, 24 female long jumpers were participated in a questionnaire survey. As a result, it was revealed that massive weight gain or loss can decrease the performance. However, the relationship between weight and performance varied from athlete to athlete. We also found that the factors affecting weight change were variety (stress, season, illness and so on) and hierarchically, and the effects of coaching on weight control differ to not only the contents but also the relationship with athletes. In conclusion, this study revealed that weight gain doesn't always lead to performance decrement and weight control should conduct adequately with consideration for the individuality.

    This study aimed to investigate the physical demands of the ultimate game in middle school ultimate players(aged 13-15yr.) in relation to the year of experience (2yr vs. 3yr). Players were tracked with a global positioning system (GPS) device and heart rate monitor during the 15 minutes of the 5on5 game. Independent t-test was performed separately in each sex to determine the effect of skill level on time spent in different heart rate zones, distance covered in the different speed categories and percentage ratio against the total distance, number of acceleration and deceleration in different intensity levels, and the number of the sprints. Male players with less experience covered more total distance, the distance at Zone3 and Zone4, and low and middle-intensity accelerations than experienced male players. However, the ratio profile shows that experienced male players tend to play more at higher intensity levels (Zone5) and lower intensity levels (Zone2). Mean heart rates were significantly higher for less experienced female players than experienced female players. Female players with more experience covered more distance at a higher intensity level(Zone4 and Zone5), but more acceleration and deceleration were seen at less experienced female players. The ultimate game was a highly physically demanded sport for middle school players. However, according to skill level, players were exposed to different physical demands that players with more experienced players tend to exhibit intermittent sports characteristics. Coaches should consider these characteristics of movements at the coaching site to have a better ultimate game training or utilizing the game for different purposes, such as cross-training.

    The purposes of this study were to clarify the effect of wrestling on the physical competence and exercise habits of elementary school students, and to show a new perspective of wrestling coaching. Through this study, we were able to draw the following conclusions.
1. The recognition of physical competence, which is the first factor of perceived physical competence, was affected by the training content of wrestling and the coordination ability cultivated in the training of wrestling, and showed an effect from the middle grades of elementary school.
2. The second factor of the feeling of control was effective from the middle grades because wrestling practice environment developed the children's grading ability, and because the coaching behavior such as goal setting and positive feedback influenced it.
3. It was revealed that wrestling has no effect on the third factor of the peer and teacher acceptance. It was suggested that in wrestling, coaching development is required to increase the membership of teammates and fellow groups.
4. It was suggested that wrestling may contribute to the establishment of exercise habits of elementary school children because the physical competence and physical fitness are improved by engaging in wrestling.
5. The experience of wrestling was related to physical competence and exercise habits, and it became clear that the continuation of wrestling may contribute to the development of physical literacy in children.

    In Artistic Swimming (AS) competitions, each performance is scored by judges. Therefore, the point of view and behavior of a coach is especially important when giving technical instructions to swimmers because they need to incorporate such information into their movements. In this study, the author, who has been studying AS coaching for not less than three years, used episode description and stimulated recall methodology to analyze an expert coach's interaction with three swimmers about “thrust”, one of the basic movements of AS. The coach has experienced the Japanese national team's coach many times and contributed greatly to training elite artistic swimmers and the development of AS. (1) The expert coach created a coaching situation considering not only relationship of trust between her and the AS swimmers, but also “interpersonal relationship” based on the context and background among the swimmers such as their positions and relationship. (2) She understood that her “verbalization” had a limit. Thus, she guessed from the swimmers' expression and behavior how much they grasped her intention, instantly searched for hints for their understanding, and explained such hints to them through various ways. (3) In the coaching scene of thrusting, one of the basic movements of AS, she created an “intentional situation” where everyone including the coach herself, the swimmers who were given instructions, and the other swimmers waiting their turn, could easily observe each other. This intentional situation was an effective situation of coaching practice to acquire the thrusting movement of AS.

    The purposes of this study were to gain knowledge to improve individual tactics through how players acquire practical wisdom by focusing on experience and reflection while providing narrative cases on practical wisdom of individual tactics of baseball batting. We conducted an interview with one college baseball player. After reviewing the case, we found the following contents.
    1) By repeatedly conducting the process to collect failure cases from game experiences and then applying the lessons of failure to the next playing opportunity, the player will be able to update his playing image immediately during the game. Thus, it is required that the objective of learning is to promote the above-mentioned process by reflecting on failure experiences.
    2) With the corrective intention of technical skills, a player becomes aware of needs for a series of processes to achieve a stable technical capability such as realization of change in skill, cause assessment, and selection for correction method. Thus, it is required that the objective of learning is to identify where the issue lies in the series of processes.
    3) By aiming to play against and conquer pitchers with individual tactics as a player never experienced before, the player attempts to acquire new tactical variations and the necessary technical skills. Thus, for obtaining new variations of individual tactics, it is recommended that players need to gain more experiences to play against pitchers with individual tactics as never experienced before.

    This study highlights the success of a Japanese junior female 100m hurdler (personal best of 13.42 sec) through a case study. She had a habit of kicking leg motion and too tight an arm swing while running. Thus, the theme of the training program was to improve her kicking leg motion and her arm swing. The training was conducted over the AprilOctober season, which was divided into two terms—the first (Apr-Jun) and the second (Jul-Oct) semesters. The training goals were set for 3–4 weeks, and the overall target was to win the under–20 (U20) National Championships in October. The main results were as follows: 1) A significant decrease in the second-semester timing of the 100mH record compared to the first. 2) A significant decrease in the second-semester value of body fat percentage compared to the first. 3) A significant increase in the second-semester value of lean body mass compared to the first. 4) Improved kicking leg motion in the second semester. 5) Extended acceleration in the race.
    As a result of improving the kicking action, she succeeded in changing her race pattern and won the U20 National Championships.

    The purpose of this case report was to describe and study the author's experience with teaching the dribble layup to a beginning basketball player, and to provide knowledge that would help other coaches teach the technique. The beginning female player had problems making a smooth transition from the dribble step to the shooting step during the catch phase of the dribble layup, and had difficulty making a stable throwing motion. Therefore, the author proposed a step-by-step practice drill to promote the connection of the two skills of dribbling and shooting, and attempted to create a movement of kicking with the axle foot at the beginning of the shooting step and develop a rhythm when catching from dribbling. Based on the practice drill, the learner shouted “un” for the final dribble and “1, 2” for the shooting step, and got the hang of the movement of entering the step and timing it together with the shouts. The findings of this study highlight the importance of placing the point of awareness on the technique before the catch phase in order to make the connection between the dribble and the shooting step smooth. Knowledge gained from this report will be helpful to other coaches teaching beginners the dribble layup.

    This study reports a coaching case of a male athlete (abbreviated to “athlete A” after this) who had a problem that left foot lands on the “under-rotation” position during second-turn phase in the discus throw. Since athlete A is the author, this study shows processes and reflections of self-coaching. First, one of the factors which caused “underrotation” was that athlete A was too self-conscious about quick touchdown of left foot during second-turn phase. Then, “turn drill without landing left foot” and “half-turn throw” were adopted as technical training to resolve “under-rotation”. Although the number of trials which left foot lands on the “under-rotation” position reduced to a certain degree after both training, the problem had not been resolved completely. However, coaching processes showed in this study can contribute accumulation of a case study to construct general theory about resolving “under-rotation” in the discus throw.