The present study was designed to examine the efficacy of a standard, print-based intervention for older adults living at home. Five hundred forty older adults randomly assigned to either (a) an intervention group (males: 113, females: 149) or (b) a control group (males: 141, females: 157) participated. Four standard, printed self-help exercise promotion materials were mailed to the intervention group for six months at 1.5-month intervals. Participants were assessed for stages of exercise behavior change and five psychological constructs posited to influence participation in physical activity (e.g., exercise self-efficacy). The main findings were as follows: 1) Chi-squared analyses showed that, compared to the control group, the standard, print-based intervention significantly promoted the upper stages of exercise behavior change in females. 2) ANOVA showed that the standard, print-based intervention significantly affected the scores for Perceived Benefits of Exercise in females. The intervention group had a significantly higher score than the control group. These results suggest that intervention using printed self-help exercise promotion materials is effective for guiding physical activity change in older female adults, but has little effect in older male adults. Controlled studies are needed to determine the types of print-based messages that are most effective, and the frequency or duration with which such intervention should be delivered.
The purpose of this study was to investigate the characteristics of racing patterns in male 800-m runners with different record levels with respect to running speed, stride length and stride frequency. Forty-nine male 800-m runners in official competitions were videotaped with video cameras at a sampling rate of 60 Hz during the whole course of the race. They were divided into four record groups according to the race times obtained as follows: Group 1 (G1), 1 min 46–47 s; Group 2 (G2), 1 min 48–49 s; Group 3 (G3), 1 min 50–51 s; Group 4 (G4), 1 min 52–53 s. The ratio of the race time to the personal record was no less than 99% for all runners analyzed. The average running speed, stride length and stride frequency were calculated for every 100 m based on the temporal data collected by reading the timer counter superimposed on the video images. The main results were as follows: 1) The running speed increased to a peak before 200 m, decreased from 200 m to 400 m, and was maintained or slightly decreased from 400 m to the finish. 2) Significant differences in running speed among the groups were observed in the middle stage of the race (120–600 m). 3) There were no significant differences in the relative running speed every 100 m among the groups. 4) The race patterns were classified by the relative running speed, stride length per height (SL) and relative stride frequency (SF) into a) The 1st half dominant with average SL and high SF for G1, b) The 1st half dominant with large SL and average SF for G2, c) The 2nd half dominant with average SL and low SF for G3, and d) The 2nd half dominant with low SL and high SF. These results indicate that the difference in running speed among the groups was large in the middle stage of the race, and that the pattern of the relative running speed was similar in all groups regardless of the performance level. Therefore, the present study suggests that the pace to achieve a goal time can be estimated by using the relative running speed.
The purpose of this study was to clarify the originality of “regard” in movement practice and to show the possibility of its development based on Georg Simmel's idea of “interaction” (Wechselwirkung). For this purpose, the study consisted of four parts: 1) an investigation of how “regard” has been grasped in physical education (P.E.) and related fields; 2) consideration of Simmel's analysis of “regard” (Blick) in “interaction”; 3) addressing the relationship between Simmel's idea of “regard” and “regard” in movement practice in terms of concrete situations; 4) consideration of the originality of “regard” in movement practice and the possibility of its development. “Regard” has been grasped as follows: 1) necessity for disclosure of one's own existence; 2) relationship between both active and passive acts; 3) capability of body, i.e. body schema as its basis; 4) the goal and way of appreciating the mind of others, and movement in P.E. and movement learning. Simmel considers “regard” as the only and absolute “interaction” between “I” and “the other”. “Looking” (Sehen) is its fundamental function consisting of three elements: “cutting out” (Herausshneiden), “giving meanings” (Sinn-Geben) and “act of consistency” (Einheitlichkeit). Based on this argument, “regard” is limited by practice, and therefore one looks at “the other” in terms of this limited “regard”. “Regard” in movement practice is characterized as follows: 1) capability of body; 2) recognition of the other's movement and the basis of reaction to it; 3) development of practical capability by change of “regard”. Therefore, the originality of “regard” in movement practice is based on capability of body and limited by practice. It is this “regard” that recognizes one's own movement practice and that of others, and substantializes the “interaction” between “I” and “the other”. This is why it is important to experience concrete “interaction” in movement practice for the development of “regard”.
The purpose of this paper is to clarify the historical currents and background, both in Austria-Hungary and Japan, that relate most directly to the specific conditions that allowed Major Theodore von Lerch to start conducting the first ski lessons for the Takada Division in 1911. The historical materials used here are the official documents preserved at the General Staff Office in Vienna with additional materials also accessed from archives in Japan. The results of this study can be summarized as follows: When Austria-Hungary notified the Department of the Army in Japan of von Lerch's arrival in Japan in the summer of 1910, they asked the Quartermaster from the Department of the Army to find skis and ski books in preparation for ski lessons. Within a month, the Quartermaster planned the ski lessons and submitted the plans to the Department of the Army in November. von Lerch notified the Department of the Army of his intention of being attached by official order to the particular army division for training where he would be able to ski early in December. Putz from the Austria-Hungary Embassy applied to the Department of the Army regarding the set permission to hold the ski lesson on the 10th of December. The Department of the Army discussed hosting von Lerch's ski lessons based on this situation as of the 12th of December, and this plan was approved, endorsed and then forwarded to the Takada Division by the 17th of December. The Takada Division obtained notice from the Ministry of the Army after the 18th, upon which the Takada Division implemented its own rules and regulations for the study of skiing, governing the conduct of training for the soldiers who would participate. The divisional commander, Gaishi Nagaoka, then ordered the start of official ski training in accordance with the rules and regulations that had been posted on the 27th, but upon von Lerch's arrival this had not yet begun.
The purposes of this study were to examine the effect of teeth clenching on isokinetic muscle strength during isokinetic elbow (60, 120 degrees per second) and knee (60, 180 degrees per second) extension and flexion using a BIODEX isokinetic dynamometer. Twenty-five American football players (19.6±1.3 years) with normal occlusion served as subjects. Isokinetic muscle strength of the elbow and knee, extension and flexion strength were measured during tooth clenching (Bite), biting with a soft biteplate (Soft), biting with a hard biteplate (Hard), and without tooth clenching (No-bite). Analysis of the peak torque per body weight and the time to peak torque yielded the following results: 1) The peak torque per body weight of elbow extension with Soft was significantly higher than with Bite and No-bite (120 deg/s, p<0.05). 2) The time to peak torque of elbow extension with Hard was significantly slower than that with No-bite and Soft (60 deg/s, p<0.05), and those with Bite and Hard were significantly slower than that with No-bite (120 deg/s, p<0.05). 3) The peak torque per unit body weight of knee flexion with Bite and Hard were significantly lower than that with No-bite (60 deg/s, p<0.05), and that with Bite was significantly lower than that with No-bite (180 deg/s, p<0.05). 4) The time to peak torque of knee flexion with Soft and Hard were significantly slower than that with No-bite (60 deg/s, p<0.05), and that with Bite, Soft and Hard were significantly slower than that with No-bite (180 deg/s, p<0.05). These findings suggest that tooth clenching and the materials of the biteplate are factors that lead to increased isokinetic muscle strength of elbow extension and to decreased isokinetic muscle strength of knee flexion. Thus it appears that tooth clenching and the materials of the bite-plate do not influence isokinetic elbow flexion muscle strength or knee extension muscle strength.
It is thought that the “singing dance”, a childcare technique advocated by Fröbel, was first performed in Japan at Tokyo Women's Normal School Kindergarten, which was opened in 1876 (9th year of the Meiji era). The part played in its introduction by Clara Matsuno, the first senior kindergartner, Fuyu Toyoda, Hama Kondo and others was clearly recorded, but there has been little study of the role played by the Reijin (musicians) belonging to the Gakubu (Japanese Imperial Court Music Department), Board of Ceremonies, Imperial Household Ministry, to whom composition of Hoiku-shoka (childcare songs) was requested, especially in relation to “singing dance”. In this study, the author attempted to clarify the creation process of the Hoiku-shoka by reference to the Gagaku-roku (The Official Document Of Japanese Imperial Court Music), preserved at the Gagaku-ka (Japanese Imperial Court Music Section) and Shoryobu (Archives and Mausoleum Department, Imperial Household Agency). The research revealed the following facts: 1. Creation process of Hoiku-shoka 1) Teaching place, schedule, honoraries to the Reijin 2) There was selection examination for the songs chosen (composed) by Hama Kondo, a kindergartner. 3) There was a plan to publish the Hoiku-shoka, but its realization took a long time. 2. Introducing process of “singing dance” 1) The concerned Reijin not only composed but also choreographed Tamigusa. 2) Shinado-no-kaze (Wind of Shinado) was originally a “singing dance”. 3) At the Gakubu-daienshukai (Great recital of dance and music) held on 30th and 31st October, 1880 (13th year of Meiji), the Gagaku-ka was thought to have organized a performance of Hoiku-shoka by the students of Tokyo Women's Normal School and the children of its kindergarten. These findings clarify the contribution of the Reijin of the Gagaku-ka to modernization of kindergarten education early in the Meiji era by not only selection of the Hoiku-shoka but also its involvement in choreography of the “singing dance” and its teaching.
The Undoukai (Athletic Association) at the Imperial University of Tokyo was a student association that consisted mainly of sports club members. The Undoukai was a departure point for Japanese sports, and led to the establishment of school sports in the Meiji period, being incorporated as a foundation in 1934. The purpose of this study is to describe the process of how the Undoukai was organized as an incorporated foundation from the late Taisho era to the early part of the Showa era, focusing on interactions among students and the university. The main documents are gathered from the Imperial University Newspaper. The results of this study are summarized as follows. 1) This study describes the history after establishment of the Undoukai, which was integrated into the Gakuyukai (Athletic and Cultural Association) at the Imperial University of Tokyo in 1920. The Gakuyukai was an all-university association that included cultural activities. However, the members of the sports clubs left the Gakuyukai and organized the Undoukai again in 1928. 2) This study clarifies two oppositional relationships among students during the organizational process of the Undoukai. One was between sports club members and the other students, and the other was between the left-wing students and the right-wing students. In both relationships, sports club members would win the understanding of non-athletic students and would distance themselves from the left-wing students. Both practices enabled the Undoukai to become independent from the Gakuyukai. 3) This study clarifies that strong assistance from the University contributed to the reorganization of the Undoukai. There were two problems that the University needed to address: one was how to prevent students' illnesses, and the other was how to discourage students from becoming inclined to the politcal left. Therefore, the University expected general students to aspire to “healthy body” and to have “healthy idea”. While the University would recommend sports to general students in order to realize the expectation of “healthy body”, at the same time it would separate general students from left-wing students in order to realize the expectation of “healthy idea”. These expectations and practices of the University provided the impetus that nurtured the Undoukai.
The purpose of this study was to investigate the effects of a physical education program based on behavioral science, which includes homework (project First-Year Physical Education: FYPE) on the health level and lifestyle of first-year college students. The study participants comprised 1,090 male college freshmen from an institute of technology in the Kinki area of Japan (intervention group, N=515; non-intervention group, N=575). The programs that were common to all the classes were as follows (the numbers correspond to the sequence of activities of the program). 1: guidance, 2–4: sports activity, 5: lecture (health science), 6–8: sports activity, 9: lecture (health science), 10–12: sports activity, and 13: summary of the class. Health behavior promotion programs were intended only for the intervention group. The programs comprised (1) education on behavioral change skills (self-monitoring, goal setting, self-reinforcement, and so on), and (2) out-of-class practical assignments such as physical education homework. We evaluated the health level and life habits of the students by using the Diagnostic Inventory of Health and Life Habit (DIHAL; Tokunaga, 2003) and evaluated their physical activity level using the Physical Activity Assessment Scale (PAAS; Wakui & Suzuki, 1997). As a result, significant intervention effects were observed with regard to the DIHAL scales for “Eating,” “Resting,” and the “Sum of lifestyle,” and with regard to the subscales of “Level of physical health,” “Eating regularly,” “Relaxing,” “Sleeping regularly,” and the “Fulfillment level of sleep.” The PAAS revealed a significant intervention effect with regard to “Daily activity,” which indicates the relatively light physical activities in daily life; however, this was not observed with regard to the DIHAL scale of “Exercise.” These results clearly indicate that physical education programs based on behavioral science and including homework can improve the overall lifestyle (namely, physical activity, eating, and resting) of first-year college students.
Phorbol 12-myristate 13-acetate (PMA) and opsonized zymosan (OZ)-stimulated superoxide-generating activity of neutrophils were measured by the cytochrome c reduction assay in 10 healthy young (21.4±0.4 yr) and 10 elderly (60.7±1.9 yr) women. Peripheral blood was collected three times, at the menstrual, ovulatory and luteal phases in the young women, and on largely the same days and intervals as those for the younger subjects in the elderly women. PMA-stimulated superoxide-generating activity of neutrophils did not change in the young and elderly groups. However, OZ-stimulated activity in the menstrual phase was significantly higher than in the ovulatory and luteal phases in the young women; no change was found in the elderly women. These results suggest that the superoxide-generating activity of neutrophils is transiently activated by physical and mental stress during the menstrual phase. This activation may occur due to a change in neutrophil receptors, signal transduction pathways and membrane fluidity without any increase of NADPH oxidase activity itself, which produces superoxide anions.
The purpose of this study was to clarify whether sprinting and jumping performance in late pubertal male students would be improved by jump training and other types of training. The subjects were classified into four groups; a jump training group (hurdle jump, skipping and bounding), a resistance training group (leg lunge, single leg squat and half squat), a complex training group, and a control group. Training was continued once a week for eight weeks. As a result, the rebound jump power [power=(g2·tf·tt)/(4·tc)], the distance covered by a standing five jump, and that covered by a standing triple jump increased in the jump training group, whereas the rebound jump contact time decreased. Moreover, the rebound jump power, the height of the counter-movement jump and the distance of the standing triple jump increased in the complex training group. In the resistance training group and the control group, each measured item showed no change. The 50-m mean sprinting velocity increased significantly in the jump training and the complex training groups. Moreover, the sprinting velocity at 10-m intervals between the 30–40-m and 40–50-m sprints increased significantly in the jump training group, as did the maximum sprinting velocity. The improvement of leg output power over a short time was considered to make a large contribution to maximum sprinting performance. The information presented is considered beneficial for improving physical education class and sports performance.
The present study was conducted to clarify causal structures among sprint performance indices and body movements during sprinting in elementary school boys. Three hundred and eighty three boys in the 1st to 6th grades performed a 50-m sprint, and the step length index, the step rate index (in which effects of differences in body height were eliminated) and body movements at ground contact were measured at the 35-m point from the sprint start. Path analysis was applied to the measured parameters at each stage for low (1st and 2nd), middle (3rd and 4th) and upper (5th and 6th) grades. From the results, the following trends were suggested: 1) There appeared to be a causal structure among indices of sprint performance and body movements. 2) For boys in all grades, the knee flexion and forward inclination of the thigh in the recovery leg were important for increasing the step length index, whereas backward inclination of the thigh in the recovery leg and forward inclination of the lower thigh in the support leg were important for increasing the step rate index. 3) For boys in the lower grade, forward inclination of the body had a greater positive effect on the height of the step length index than in other grades. 4) In the middle grade, knee flexion of the recovery leg had a greater positive effect on the height of the step length index than in other grades. 5) In the upper grade, forward swing of the thigh in the recovery leg had a greater positive effect on the height of the step rate index, although inclination of the lower thigh in the support leg was higher than in other grades.
Comprehensive sports clubs are designed for residents of urban communities comprising socially independent, unrelated individuals. Therefore, such clubs would not be viable in rural districts where strong relationships among residents still exist. The purpose of this research was to consider the kind of comprehensive sports club that might be viable in the context of a rural community, by analyzing the relationship between the lifestyle and sports practices of the local residents. Taking Oguni Town as a concrete example, the social structure of the district was analyzed along with the relationships between life structure and sports practices. For the former analysis, interviews with representatives of the local residents (N=3) were used, and for the latter a questionnaire survey (N=252) was employed. Analysis of the social structure of the district revealed a tendency for privacy and fluidity, similar to the situation in an urban area. Conversely, the basic lifestyle of a ‘village’ - or, its rootedness-preserved the life structure of the community. Characteristics of the ‘village’ included a tendency to form local groups through the activities of intermediate groups. From this analysis of the relationship between life structure and sports practice, it can be concluded that the life structure of a rural district with strong rootedness has a great influence on the quality of sports practices, i.e. the preservation of group events. These results suggest that a comprehensive sports club in a rural district should not be a functional group focused on individuals but rather adapted to the lifestyle of the ‘village’ community. It should also serve the function of building a network between intermediate groups.
Japanese married women only began participating widely in sports after the Tokyo Olympic Games in 1964. It is often said that participation in sports by housewives symbolized their liberation from isolated domestic life, thereby promoting gender equality. This thesis examines the development of housewives' sports activities and the characteristics of the sports institution, taking “Mums' Volleyball” as the main example, and concludes that those housewives undertook their role without themselves realizing that they were contributing to national economic growth, thereby exaggerating the sexual division of labor. The perpetuation of “housewifeliness” signifies repeated states in which housewives were liberated from their daily household routine, and then were empowered to fulfill their roles as home-makers even more effectively by the sports activities in which they participated. Thus the perpetuation of “housewifeliness” could be expressed as a circular diagram illustrating repeated liberation from “housewifeliness” and its prepetuation. With the development of their sports activities, the image of housewives changed from “isolated” to “cheerful”, and then to “autonomous”, and thus the circle could be considered a spiral diagram. In order to examine the concept of perpetuation of “housewifeliness”, how married women came to be regarded as “housewives” will be outlined, then the reasons why the housewives' sports movement occurred in the 1970s will be discussed. Finally, analysis of the institutional characteristics of “Mum's Volleyball”, such as ideology, rules, facilities for training, etc., will explain how “housewifeliness” was perpetuated. “Mums' Volleyball” was an informal name, and “Housewives' Volleyball” was the official one. Although since the 1970s, the word “housewife” has almost never been used because of its gender inference, it has been used in many cases with reference to sports activities by married women. As the word “housewife”, however, symbolized a good wife and mother, sports activities were accepted and acknowledged by their husbands and their families and, ultimately by society. The housewives who perpetuated “housewifeliness” contributed to the country's economic growth by ensuring that their husbands were always in top condition for work. In the meantime, they were required to have organizational skills, for example, skills for managing their teams, sports associations, and various tournaments in which they participated. Thus the housewives' sports activities could be said to have two faces: one was to free housewives from home-bound chores, encouraging them to have social empowerment, and the other was to accelerate their sexual division of labor as home-makers.
This study investigated the applicability of item response theory to motor skill tests. In particular, we focused on the evaluation of children's motor skills using three Rasch models. Motor skill tests included the number of successes in a given trial, the number of successes in a given time, and a subjective rating regarding the form of the motor skill. We used Andrich's Binomial Trials Model, Rasch's Poisson Counts Model, and Masters' Partial Credit Model, respectively, to derive a synthesized motor skill ability using the item response theory from two or more motor skill test scores. A synthesized motor skill ability was computed by combining these three models and applying them to children's motor skill test items. The sample consisted of 205 kindergarten-aged children, and 8 motor skill items were tested, including (1) side jump, (2) jumping over a 30-cm high rope with hands on a board, (3) kicking and aiming a ball, (4) catching a ball, (5) rolling and aiming a ball, (6) forward roll, (7) side roll, and (8) jumping and turning 90 degrees until a complete 360-degree turn is completed. The following results were obtained: 1) The correlational structure among motor skill test items for this sample had high homogeneity and was one-dimensional. High correlations were found between two sets of Difficulty Parameters, which were computed from two randomly divided subgroups. Obtained Difficulty Parameters were not affected by the sample used. 2) Significant correlations were found between synthesized ability parameters and age, standing height, and body weight, indicating that the motor skill ability parameters measured a latent motor skill, which developed with advancing age. 3) A high correlation was found between synthesized motor skill ability and the Principal Component Scores computed by Principal Component Analysis. However, ability parameters showed lower correlations between motor skill test items and age and physique than Principal Component Scores. In contrast, high correlations between motor skill ability parameters and motor skill test items were found. Finally, the likelihoods for obtaining a synthesized motor skill parameter and an expected score for each test item were obtained, and an explanation for using these two values was provided.
The purpose of this study was to analyze three-dimensionally two groups of baseball strikers, i.e. high and low swing speed groups, and to compare the kinematics of their upper limb motion. Sixteen skilled male strikers were videotaped with two synchronized high-speed video cameras operating at 200 Hz. One trial in which the maximum bat head speed was achieved was selected for each subject and digitized to obtain three-dimensional coordinates of the segment end-points and the bat using a DLT technique. Subjects were divided into High (n=8) and Low (n=8) groups according to the bat head speed. The angles compared between the two groups were abduction-adduction, horizontal abduction-adduction, flexion-extension and internal-external rotation for both shoulders, flexion-extension for both elbows, supination-pronation for both forearms, radius-ulnar flexion, and dorsi-palmar flexion for both hands. The sequential data were normalized with the time from the point when the speed of the grip was over 3 m/s to the ball impact, and then averaged. 1 Angles of elbow extension, forearm supination of the top arm, and ulnar flexion of both hands were much changed. However, the angles of both shoulder joints, bottom elbow and bottom forearm showed little change. 2. The High group showed significantly larger shoulder adduction and horizontal adduction of a bottom arm than the Low group in 0–10% time and 50–70% time (p<0.05). The High group showed significantly smaller top elbow extension than the Low group in 40–70% time and 90–100% time (p<0.05). 3. The High group showed significantly smaller top hand supination than the Low group in 100% time. In the time, the High group showed significantly larger bottom forearm pronation than the Low group in 50–70% time (p<0.05). The High group showed significantly larger dorsiflexion of the bottom hand than the Low group in 20–30% time (p<0.05).
The purpose of this study was to verify the effectiveness of modified basketball games based on on-the-ball decision-making and off-the-ball movement. Two types of numerically modified basketball games, “3 on 2” and “3 on 3”, were played by two 6th grade elementary PE classes. Twenty-four students participated in the 3 on 2 games, and 28 students in the 3 on 3 games. All games were videotaped, and the Game Performance Assessment Instrument (GPAI) was used for data analysis. This instrument allows counting of the frequency of on-the-ball decision-making and off-the-ball support movement, and assists in judging the performance of students in situations such as shooting, passing, ball-keeping, and supporting, as to whether or not these are appropriate. The main findings are summarized as follows: 1. The number of students who experienced on-the-ball decision-making and off-the-ball support situations, and the average frequencies of these experiences, were higher in the 3 on 2 games than in the 3 on 3 games. 2. In the 3 on 2 games, the numbers of students who performed appropriate passing, ball-keeping, and support were significantly higher than in the 3 on 3 games (p<001). 3. The rates of appropriate shooting, passing, ball-keeping, and support were significantly higher in the 3 on 2 than in the 3 on 3 games (p<01). The 3 on 2 basketball game was shown to be very effective, allowing upper elementary grade students to learn appropriate on-the-ball decision-making and off-the-ball support movement, in comparison with the 3 on 3 game.
The purpose of this study was to clarify: 1) the background that led C. Diem to attempt the reconciliation between Deutsche Turnerschaft (DT) and the sports federations (Deutsche Sportbehörde für Leichtathletik and Deutscher Fusßallbund), 2) the way in which Diem proposed to control each field of activity, 3) how Diem considered his standpoint in this attempt, and 4) die Turner's reaction to Diem's attempt. The findings were as follows: 1) When Diem played a leading role in the activities of Jungdeutschlandbund and the organizing committee of the Berlin Olympics, in which the DT and the sports federations were requested to cooperate, he insisted on a reconciliation between the two. 2) Diem attempted to reconcile the DT with the sports federations by insisting on specialized control of each field of activity. 3) As the leader of the Deutsche Sportbehörde für Leichtathletik and the leader of the Berlin Olympics organizing committee, Diem insisted on specialized control. He promoted reinforcing the mind and body of Germans as the common aim of the DT and the sports federations. This was the common aim of the organizations that participated in Jungdeutschlandbund. In this aim, Diem found a point of accord between the DT and the sports federations. 4) F. Goetz stated that the control rights for each field of activity could not be entrusted to other organizations, and rejected Diem's reconciliation plan. The articles about this topic that had been published in der Deutsche Turnzeitung and der Monatschrift für das Turnwesen, also reflect the intransigence of Goetz. However, when Diem described the reconciliation plan in the book published in 1914, not only did die Turner adopt an intransigent attitude like Goetz, but also die Turner agreed with Diem, who stated that the control of each field of activity should be regulated.
The purpose of the present study was to clarify the factors involved in deceleration in the last phase of a 100 m sprint by comparing the kinetics of the lower limb joints between the maximal running velocity phase (Max) and the deceleration phase (Dec). Five male collegiate sprinters, running 60 m and 100 m at maximal effort, were videotaped with high-speed cameras (250 fps) and the ground reaction force (1000 Hz) was measured at the 50-m and 85-m points. The kinematics and kinetics of the lower limb joints were then calculated. The results were as follows: 1) The deceleration of running velocity was due to a decrease of stride frequency. 2) In the Dec, braking impulse increased, but propulsion impulse decreased significantly. 3) Significant decreases were found in joint torque and negative power exerted by ankle plantar flexors. 4) Hip negative work exerted by hip joint torque in the late support phase tended to decrease, and it is thought that this decrease affected the delay of hip-flex movement during the early recovery phase. These results reveal that the function of the ankle has a direct influence on deceleration, and suggest that the negative work exerted by hip joint torque during the support phase may help to maintain hip-flex movement during the early recovery phase in the final phase of the 100-m sprint.
Recently, “Nijiku” sports motion theory has been proposed and is being widely disseminated for many types of sports events including association football (soccer). It appears that this theory has some scientific basis for improving performance in sports. However, as the theory did not follow the necessary procedures, to date, its scientific validity has never been examined. This paper was designed to precisely examine the scientific validity of the “Nijiku” sports motion theory in relation to soccer from the viewpoint of science philosophy and biomechanics. Falsifiability is an important concept in science. However, only a few objective data—the ground reaction force of the supporting leg during soccer kicking and the peculiar motion referred to as “unfasten knee” motion—were demonstrated in the related literature with incorrect interpretation, and there were no falsifiable data to prove the existence of “Nijiku” during sports actions. Thus, it has been considered that the “Nijiku” sports motion theory runs contrary to the principle of science. Moreover, there are many misleading descriptions, particularly with regard to the effect of gravity. As a result, it can be considered that the “Nijiku” sports motion theory is classified as a “pseudoscience” labeled inaccurately or misleadingly portrayed as science. Scientific counterarguments to stimulate debate on these matters by the proponent and/or supporters are expected.