Three-dimensional (3-D) motion analysis is widely used in numerous fields of physical education, including biomechanics, coaching and test and measurement. Among the available 3-D motion analysis methods, the nonlinear transformation (NLT) method is frequently used. Many automated motion capture systems currently utilize this method. However, as this method is based on the perspective projection of ordinary cameras, its use is limited in various situations. Because ordinary cameras have a relatively limited angle of view, they cannot cover a wide target area or be set up near the target area. In this study, we propose a method for 3-D data collection using omnidirectional cameras that can capture images of the entire celestial sphere. For the points of interest, the longitude and latitude of the celestial sphere were obtained from the image of an omnidirectional camera. The direction of the camera ray was determined by considering the polar coordinate system with the longitude and latitude. During the calibration process, the relative position and orientation of the omnidirectional cameras were determined from the images of the control points with unknown 3-D coordinates. We verified that the accuracy of the proposed method (resultant error: 0.34%) was comparable to the accuracy reported in preceding studies regarding traditional NLT and omnidirectional Direct Linear Transformation-inspired methods.

This study aimed to clarify the structure and characteristics of coaching concepts held by Japanese high school baseball coaches through multivariate analysis. After conducting a preliminary survey using an open-ended questionnaire, a selective questionnaire survey was conducted among 415 Japanese high school baseball coaches, and an exploratory factor analysis was conducted. We found that their coaching concept could be assessed based on three factors. These factors were “Social Literacy,” “Pride in Kokoyakyu (=Japanese high school baseball),” and “Baseball Literacy.” The scale developed in this study had a certain degree of reliability and validity and made it possible to understand the coaching concept of Japanese high school baseball coaches. The Kokoyakyu coaches’ coaching concept could also be classified into five types and this distribution tended to vary depending on the coaches’ attributes and coaching environment. Overall, the results of this study suggest that Kokoyakyu coaches are successfully using the “Koshien taikai ” (Japanese High School Baseball Championship) in their coaching. Moreover, the Kokoyakyu coaches’ coaching concept can be understood as having been formed and established both by the Kokoyakyu system, which is developed within the unique historical and cultural context of Japan, and the social gaze directed at Kokoyakyu itself. In particular, the “Pride in Kokoyakyu” coaching concept suggests the existence of some sense of “tradition.”

PURPOSE: This study conducted a scoping review of existing intervention studies with the aim of identifying the therapeutic-educational significance of martial arts for ASD. METHODS: This study followed the PRISMA extension for Scoping Reviews (PRISMA-ScR) to collect and select articles. Searches were conducted using PubMed and Science Direct databases, using terms such as “martial arts” and “Autism”. The collected literature was screened according to eligibility criteria and the quality of the studies was assessed using the PEDro scale. RESULTS: In the end, 22 articles were selected, showing multifaceted effects on the improvement of ASD core symptoms and the development of socio-emotional, cognitive, and physical functions. On the other hand, research gaps were identified regarding study areas, subjects, and methods. CONCLUSION: The scoping review organized the results of previous studies and added evidence that reinforces the therapeutic-educational significance of martial arts. It also indicated that additional intervention studies are needed to conduct a meta-analysis.

Recently, the cortisol awakening response (CAR) has been focused as an index of chronic stress. Chronic, accumulated stress through burnout is known to result in uncontrollable HPA axis stress responses that cause abnormal CAR. However, the effects of burnout tendency on CAR in athletes remain unclear. This study examined the effect of burnout tendency on CAR in athletes. Participants were top-level female university athletes (N=45). Among them, the results of 40 participants were analyzed after excluding five participants that experienced measurement problems. The burnout tendency was evaluated using the Athletic Burnout Inventory (ABI). The participants were classified into the High BO group (N=12) with high burnout scores and the Low BO group (N=28) with low burnout scores. They were instructed to collect saliva at home, just after waking up, as well as 15 minutes, and 30 minutes later. The concentration of cortisol in saliva was estimated using the Enzyme-Linked Immuno-Sorbent Assay (ELISA). The results revealed higher CAR and AUCG tendencies in the High BO group compared to the Low BO group. However, this possibility has not been sufficiently supported statistically in the current study. We should revalidate these findings by ensuring an adequate number of samples estimated from the effect size. These findings indicate a new physiological index for assessing burnout tendency, which could contribute to better understanding the physiological mechanisms of burnout onset.

The aim of this study was to investigate the relationship between wheelchair velocity and head and trunk movements by analyzing time series data of the initial acceleration phase of the 100-m sprint of three male quadriplegic wheelchair athletes in the T52 class. While sprinting 100 m at maximum effort, the athletes’ propulsive movements were analyzed from start to 13 m using a motion capture system. In many strokes, wheelchair velocity increased slightly in the first half of the recovery phase and decreased tremendously in the second half. Peak angular velocity of trunk extension was observed in the first half of the recovery phase from release, and peak trunk extension angle was observed in the first half to the middle of the recovery phase. The results suggested that trunk extension contributes to increased wheelchair speed during the recovery phase. However, athletes in the T52 class are unable to perform active trunk extension due to their inability to demonstrate trunk muscle strength. It is speculated that the trunk extension observed in all of the present athletes is attributable to the reaction produced by pushing the hand-rims. Furthermore, the findings suggested that head movement is connected to trunk movement and is important for efficient trunk flexion/extension.

Understanding the interplay between events host region stakeholder networks and processes is essential to comprehend the delivery and sustainability of legacy. While previous studies have suggested the need to focus on building measurable and visible pre-event legacies, less attention has been paid to the effectiveness of legacy network governance associated with sporting events. Therefore, this study examined the process of legacy planning associated with the World Masters Games 2021 for legacy building and analysed the structural and functional characteristics of the legacy network governance. This study used qualitative analysis to explore the governance structure and functional characteristics of pre-event legacy building in host cities in the Kansai area of Japan. The results indicated that, in the pre-event phase, the Legacy Creation Committee contributed to the effectiveness of legacy project implementation by monitoring the activities and interactions of event stakeholders and mutually sharing their vision for the post-event period. In addition, this study contributes to our understanding of the effectiveness of legacy network governance by emphasising the importance of governance between event stakeholders in a regional cooperation system.

In recent years, a number of health issues among adolescents in Japan have become highlighted. One of the major issues in school health is thinness among high school girls. Thinness is closely related to low energy intake, which can lead to menstrual dysfunction and low bone density. It is important to acknowledge these issues as health disorders that are specific to girls, and to consider measures for their prevention. The purpose of this study was to clarify the current situation of health disorders specific to high school girls, and to examine their level of awareness about them. Between March 2018 and February 2019, we conducted a self-administered questionnaire survey targeting 1,551 high school girls from 10th to 12th grade in 32 schools across 7 prefectures. This revealed that 18.7% of the girls were classified as “thin” based on Body Mass Index. In addition, many girls (more than half) had one or more signs of low energy intake, menstrual dysfunction, and history of stress fracture. The survey indicated signs of health disorders specific female high school students, suggesting that this is an important issue that needs to be addressed. The results also indicated that knowledge regarding health disorders was insufficient, as the overall correct answer rate was 50% or less. This was partly related to the presence or absence of health disorders specific to girls. In the future, it will be necessary to clarify the relevant factors that ought to be considered for comprehensive education designed to prevent health disorders specific to girls.

This systematic review and meta-analysis investigated the effects of flywheel (FW) resistance training on jump performance in athletes and nonathletes. Four electronic databases were searched (PubMed, Cochrane Database, Web of Science, and Igaku Chuo Zasshi) for studies published on or before November 18, 2023. Reports on randomized controlled trials of FW resistance training in healthy untrained people and athletes were included for analysis. Comparisons were made between FW resistance training and non-exercise controls or traditional resistance training. The primary outcome was defined as jump performance (countermovement jump, squat jump, and drop jump) and secondary outcomes were muscular strength and mass. The standardized mean difference (SMD) with 95% confidence intervals (CIs) was calculated for quantitative indices. A random-effects model was used for pooling. Of the 167 studies identified, 27 satisfied the inclusion criteria. Meta-analysis of jump performance revealed the superiority of FW resistance training to non-exercise controls (SMD 0.89, 95% CI: 0.54, 1.25). The subgroup analysis showed that FW training improves jump performance in both athletes and non-athletes. In addition, the effect of FW training on CMJ was more effective than resistance training in athletes only (P=0.05). These results indicate that FW resistance training is an effective intervention for improving jump performance.

The purpose of this study was to investigate the kinematics and kinetics of pelvic rotation in mini-hurdle sprint, including regulated step length and increased step frequency, by comparing mini-hurdle sprint to normal sprint. Twelve male sprinters performed a 60 m sprint with mini-hurdles from a standing start and a 60 m regular sprint from a crouching start. Three-dimensional motion analysis was performed to investigate the kinematics and kinetics of pelvic rotation in the mini-hurdle sprint. The step frequency was significantly higher, and the step length was significantly lower in the mini-hurdle sprint than in the normal sprint. The pelvic rotation angle at toe-off and displacement of the pelvic forward rotation toward free leg side angle in the stance phase were significantly greater in the mini-hurdle sprint than in the normal sprint. The integrated contributory component of the lumbosacral joint torsion angular impulse was significantly greater during the stance phase and smaller during the flight phase in the mini-hurdle sprint than in the normal sprint. Overall, the mini-hurdle sprint exerted the free leg side lumbosacral joint torsional torque was greater during the stance phase and smaller during the flight phase compared to the normal sprint, resulting in the greater forward rotation on the pelvis of the stance leg side toward the free leg side prior to toe-off and contributing to faster recovery leg motion to increase high step frequency.

PURPOSE: To our knowledge, there is no systematic review of swimming and aquatic exercise intervention studies for Autism Spectrum Disorder (ASD) and Attention Deficit/Hyperactivity Disorder (AD/HD). Therefore, we conducted a scoping review of swimming and aquatic exercise intervention studies for ASD and AD/HD with the aim of identifying outcomes and issues in previous studies. METHODS: This study was conducted in accordance with the PRISMA extension for Scoping Reviews (PRISMA-ScR), and articles were collected and selected. We used PubMed, Science Direct, J-STAGE and CiNii Research as databases. Searches were conducted using terms such as “swimming” “Autism” and “AD/HD”. The collected literature was selected according to eligibility criteria, and the quality of the studies was evaluated using the PEDro scale. RESULTS: Finally, 40 articles were selected and analyzed for (1) study areas and publication date, (2) sample size and participant profile, (3) study design and quality, and (4) intervention and measurement methods. The results showed that, despite challenges in the field, size, and quality of the study, ASD and AD/HD symptoms improved and multifaceted effects on physical, cognitive, and socio-emotional development were observed. CONCLUSION: The scoping review clarified the achievements and issues of previous studies and indicated the therapeutic significance of swimming and aquatic exercise for ASD and AD/HD.

Athletes frequently assert their ability to foresee outcome in an upcoming game, often attributing it to so-called sixth sense. This paper investigates whether this foresight is genuine prediction, or a postdictive reconstruction that emerges post game. We conducted a study with 113 athletes to unravel this cognitive phenomenon. Participants completed a pre-game questionnaire, including queries about their mental and physical states, and more. Key to our investigation was the question: How do you think you will perform today? Subsequently, after the games, we administered a similar set of questions, introducing another critical query focused on postdictive reconstruction: How did you think you would perform this morning? Remarkably, even with the same question asked within 24 hours to the same participants, 60.2% of athletes altered their memory of their initial predictions, revealing a clear instance of postdictive reconstruction. Furthermore, an intriguing pattern emerged: those who experienced defeat tended to revise predictions negatively, while victors leaned towards more positive revisions. This interaction turned out highly significant, challenging the conventional cognitive tendency to maintain consistency with one's own past. These findings suggest an automatic and implicit inclination among athletes to postdictively adapt their memories of performance predictions to align with actual outcomes. Our study provides compelling evidence that athletes' claims of intuitive prediction are primarily postdictive in nature. This cognitive process sheds light on the role of memory in self assessment and the dynamic nature of human cognition, offering insights into athletes' psychological experiences and the broader domain of postdiction.

Coronavirus disease 2019 (COVID-19) pandemic started in December 2019 in Wuhan (China) and spread over the entire world causing many hundreds million confirmed cases and over 6 million deaths. But containment measures (especially lockdowns) installed by all countries affected the body due to the sudden drop in physical activity. In this review, it was showed the degree of physical inactivity, probably diseases caused by sedentary behavior and their treatment. This review aims to sunlight effects of COVID-19 pandemic lockdowns on physical activity and fitness, and their possible remedy.

From a constructionist perspective, this study analysed the extent to which sports coverage arouses public identity of belonging to a specific nation, focusing specifically on newspaper coverage of the 2023 World Baseball Classic in Japan, and clarified the type of ‘discourses of nationalism’ were evoked in the coverage. Three types of nationalistic discourse were identified: those centered around ‘us’ (1), discussions concerning the ‘other’ (2), and dialogues involving the ‘internal other’ (3). First, regarding (1) the ‘us’ discourse, we focused on comments about the style of play of Japanese players and the Japanese national team, which was dominated by the term ‘small baseball’ prior to the WBC 2023. ‘Small baseball’ is an offensive style of play based on the assumption that Japanese players are physically weak and that they score runs by hitting singles and aggressive base running rather than hitting home runs. As the tournament progressed, however, commentary on ‘small baseball’ diminished and the ‘power’ of the Japanese players was emphasised instead. At the same time, ‘togetherness’ was emphasised, and many episodes reinforcing this were reported. Next, with regard to (2) the ‘other’ discourse, we looked for comments that stereotyped the opposing nation. However, we did not find symbolic boundarydrawing expressions of self and other, or overtly hateful expressions towards the ‘other’, as is the case in British newspapers. However, this does not mean that there was no bias against the ‘other’ in the Japanese press. Japanese coverage of the WBC 2023 easily stereotyped certain nations by bringing in characteristics of other sports, and naively stereotyped nations such as Italy and Mexico based on the very broad regional characteristics of Latin culture. Such stereotypical commentary was more common in the sports press than in the general press. Finally, with regard to (3) the ‘inner other’ discourse, we focused on the representation of Lars Nootbaar, who was selected for the Japanese national team for the WBC 2023. Before and during the tournament, his dedication, courage and ‘uniquely Japanese’ style of play, as well as his attempts to assimilate into Japanese culture in various aspects, were positively reported. Such commentary was intended to underline his moral qualifications for the national team, and the term ‘samurai’ was used to bestow upon him a symbol of approval.

To gain a deeper and more detailed understanding of the mechanisms underlying propulsive force generation in wheelchair racing, we developed a testing simulator that enables us to perform precise adjustments of wheelchair-settings. The system incorporates adjustable parameters, such as the camber angle, wheel position, and driving load, allowing for the precise replication of a realistic wheelchair racing situation. A pair of torque meters on the simulator's axles enable direct measurements of wheel torque and velocity. A test pilot who is an elite wheelchair racer with SCI (T52, World Para Athletics Medalist) participated in our comparison of three conditions with different wheelchair-settings: (1) original, (2) camber angle-modified, and (3) wheel position-modified. We analyzed the wheelchair racing performance, such as wheel speed, total torque output, and the timing of torque generation. We quantified the relationship between the hand and handrim position and observed that the timing (angle) of peak torque generation was 107.1±3.8°. The results indicated that higher wheel speed (277.4±2.6, 301.2±2.6, and 283.1±3.8 rpm) and deeper peak torque angle (107.1±3.8, 123.7±5.4, and 122.5±13.0°) in the camber angle and wheel position-modified settings compared to original setting. A quick and precise modification with our developed simulator offers insights not only for the improvement of performance but also for the customization of individuals’ racers. Our findings demonstrate the utility of torque measurement in understanding racing wheelchair propulsion mechanisms, contributing to advancements in para-athletics and wheelchair-settings based on individual residual functions.

Young adults experience a variety of biological and social developments that interfere with their sleeping routine resulting in the disruption of Chronotype leading to inadequate sleep. Hence, lack of enough sleep triggers metabolic as well as hormonal changes that could increase appetite and cravings causing a decrease in insulin sensitivity that may pose a risk for obesity and weight gain. Thus, the prevalence of obesity and overweight amongst young adults is rapidly increasing despite numerous exercise campaigns necessitating the need to investigate the connection between sleep duration and its association with anthropometric variables in the samples of young adults. A total of 134 young adults (43 males, 89 females; age 20.02±0.96) were assessed on basic anthropometrics tests and completed 14 days record of daily sleep duration. Cluster analysis was used to group the samples based on their sleep duration while the Mann-Whitney U test was employed to ascertain the differences in physical characteristics between the samples and a Multivariate logistic regression model was used to check the potential effects of confounders (physical activity, gender, and age) variables toward sleep patterns prediction. It was demonstrated that a shorter duration of sleep is associated with higher anthropometric status. Essentially, upon adjusting for confounding factors in multivariate analysis, it became clear that only BMI contributed to sleep duration. Furthermore, univariate analysis revealed that the hip circumference and waist-to-height ratio of inadequate sleepers were higher compared to that of adequate sleepers. Moreover, a good proportion of the samples examined in the study were unable to clock the minimum recommended hours of daily sleep duration per day and none of the confounders had any significant effects on sleep pattern in the study population. It is therefore postulated from the findings of the current investigation that an inadequate sleeping routine may intensify the risk of obesity and weight gain. Thus, public health campaigns should not only be directed towards maintaining regular exercise but also should incorporate adequate sleep, especially amongst adolescents to avert the increasing rise of obesity and overweight globally.

Identification and prevention of injury trends are required to improve the player welfare in rugby. Seasonal injury trends were influenced by external factors such as COVID-19 and changes in laws. This longitudinal injury surveillance study aimed to analyse seasonal biases in Japanese collegiate rugby. A total of 211 male Japanese collegiate rugby players were included in the study over seven seasons from 2017 to 2023. The team’s athletic trainers recorded injury data and exposure times during rugby matches and training to analyse the injury incidence, severity, burden, anatomical regions, type of injury, and mechanisms. The correlation coefficient between seasonal incidence and mean severity trends showed a significantly strong negative correlation (r = −0.83, p = .020). The mean severity tended to increase when the injury incidence was low. The incidence of injury decreased only in the season immediately following the COVID-19 outbreak, whereas the mean severity increased. In the season following the revision of the graduate return-to-play protocol concerning concussion and tackling height, the incidence of injury remained at the same level as in the previous season. Throughout the year of the competition, a trend towards a higher incidence of lower limb injuries was observed, whereas the risk of head/neck and upper limb injuries tended to increase in the latter part of the competition period. Although external factors also influenced seasonal injury trends, the trends in the types of more frequent injuries varied by season. Injury prevention and training plans should consider seasonal trends in rugby players.

This study aimed to compare the spinal kinematics of the squat and deadlift at high load weights using a model in which the trunk is divided into multiple rigid body segments. Thirteen subjects performed the squat and deadlift under load conditions of 90% of their one repetition maximum. Reflective markers were attached to distinct landmarks on the participants’ bodies; six markers were placed at the tips of specific spinous processes, thus creating a two-dimensional trunk model with six rigid body segments on the sagittal plane. In addition, a three-dimensional optical motion capture system with 12 cameras was used. Regarding angular displacement by spine region, both exercises showed greater angular displacement at L3 and S1. In the angular displacement curves by spine region, the deadlift showed significantly greater flexion angle displacement at T12 and L3 than the squat from 0-98%, 0-99% of the time. In conclusion, the deadlift lifts with the lumbar vertebrae flexed compared to the squat, so that the mechanical stress may be concentrated on the lumbar vertebrae.

This study seeks to examine the trajectory patterns of physical activity and identify its association with exercise habits in older adults while considering differences in trajectories between sexes. Secondary data from women and men aged 65 years and older collected in 2021 in Japan were analyzed. First, trajectory patterns of exercise habits was extracted. Subsequently, the relationship between the trajectory patterns and current exercise habits was examined. The results showed that the trajectory patterns of exercise habits in the three classes follow a similar pattern among women and men. One of them was consistently inactive throughout the life. Other two classes were delineated according to the degree of decline in physical activity from adolescence to adulthood. One female-specific class was found wherein, the physical activity decreased from adolescence to young adulthood and then increased again with aging. Two male-specific classes were observed. One was consistently active throughout the life course and class and the other slightly decreased in physical activity from adolescence to adulthood. A partial proportional odds model revealed that those who continued exercising from childhood to adulthood were more likely to be physically active in late adulthood than those who were consistently inactive. The female-specific finding was that those who increased the level of physical activity from young adulthood had a higher probability of being active in late adulthood. The male-specific finding was that those who were physically active until adolescence but became inactive in adulthood had a lower probability of being physically active in late adulthood.

This study aimed to clarify the physical demands on female rugby union players in Japan by analyzing the running performance of female rugby union players during matches and comparing those players or male rugby union players. Elite male and female rugby union players wore a Global Navigation Satellite System device with an integrated three-axis accelerometer during official matches to measure the total distance, distances traveled by different speed zones, and maximum speed. Physical demands of the variables per match were determined based on the data from the female rugby union players. Comparisons between female and male rugby union players showed that the high-speed running distance (p<0.01) and maximum speed (p<0.01) were significantly lower in the female rugby union players. At the same time, no significant differences were noted in the total distance. The data showed that the female rugby union players had a comparable but the lower high speed running performance during a match compared to male players, suggesting the importance of training focusing on increasing intensity for improving performance.

The purpose of this study was to identify issues related to the treatment of sex/gender in studies on the effectiveness of athletic club activities, conducted by comparing individuals belonging and not belonging to athletic clubs, through a critical review of gender and sexuality perspective. The materials for this review, “studies on the effectiveness of athletic club activities”, were collected according to Imashuku et al. (2019). The present study was conducted with reference to previous work that had pointed out existing problems related to gender perspective. In addition, to clarify the perspective of this study, transition of the gender concept was summarized, along with a discussion of sexual diversity. The gender of the respondents in 149 articles was collected. Among them, 12 articles did not report the gender of the respondents (8.1%), 12 articles reported all-female samples (8.1%), 25 articles reported all-male samples (16.8%), 91 articles reported both female and male samples (61.1%), and 9 articles included “neither,” “blank,” or “no-answer” in addition to female and male samples in the analyses (6.0%). An asymmetric nature between the all-male samples and all-female samples was evident. Articles with all female samples stated the reasons for setting the participants, unlike those with all male participants. In articles that included both female and male participants in the analysis, it became clear that there were problems with analytical methods that ignored gender differences or assumed sex differences. In addition, there were problems with interpretation that left gender differences unaddressed or considered them in terms of sex-related traits. The present study also reviewed how sexual diversity can be masked due to research design, exclusion of “no-answer,” and non-consideration of minorities. Finally, using one article as the object to be considered, a concrete example of the significance of introducing a gender perspective was included. Through this review, it is argued that there is a need to re-examine “studies on the effectiveness of athletic club activities” from a gender perspective, and also for social construction of gender and sexual diversity in research design, analysis and discussion.

Teaching of the “Fosbury flop” in junior high school has high educational and developmental value for students. However, it is often the case that the teaching and learning methods in this class do not work well for some students because they are inconsistent with their tendency to interpret information. Therefore, learning material based on multi-interpretability has been created to overcome this difficulty for both teachers and students. Currently, as this learning material only has theoretically guaranteed effectiveness, it needs to be examined empirically. Moreover, any guaranteed theory also needs to be criticized empirically. In order to achieve this empirical examination, it is necessary to prove its effectiveness as a subjectivity study because of the nature of the theory behind the creation of the material. No consensus regarding a research method for subjectivity research has yet been established. Therefore, the purposes of the present study were (1) to verify the effect of the learning material based on multi-interpretability of “Fosbury flop” lessons in junior high school, and (2) to create a reasonable proposal for the research method using a subjectivity research approach. With regard to (1), use of a learning material based on multi-interpretability can enable unlearned items to change shape according to already learned items after execution and can provide anchoring biases in learners before execution. Thus, application of multi-interpretability is effective, and the “Fosbury flop” is easier to learn when these learning materials are employed. With regard to (2), it has been demonstrated that the method above can be adapted to subjectivity research and the procedure can be established, yielding positive results.