Judo Tournament Research Articles

A critical update to earlier research findings about the historical roots of gonosen-no-kata – “Forms of post-attack initiative counter throws”

The purpose of the present paper is to provide a critical update to previously published findings about the historical background of gonosen-no-kata (“Forms of Post-Attack Initiative Counter Throws”), a non-officially accepted kata of Kodokan judo that achieved some popularity in select European countries. We applied historical methods and source criticism to newly acquired evidence in this way offering a careful critical analysis of this kata’s origin, history and background. Expanding our earlier finding, i.e. the kata’s first verifiable European appearance in London, 1926, from 1927 onward it was spread throughout Europe by a number of judo teachers of Japanese origin. However, the results of this paper now also lead us to firmly refute the caution we had expressed earlier that gonosen-no-kata might well not be of Japanese origin. Indeed, the kata shows up for the first time in November 1915 when it is on display as part of the program surrounding the 20th Waseda University Judo Tournament in Tokyo where it was shown by a pair of judoka, named Nagae and Endo. From then on, the kata was regularly publically demonstrated in Japan at judo contests during the Taisho era (1912-1926) whenever a team from Waseda University participated. Among its most significant early proponents in Japan were Waseda students Endo Moriya, Ninomiya Sotaro, and Yasuoka Toraki. Waseda University’s former chief-instructors Miyakawa Ikkan (1885-1944) and Takahashi Kazuyoshi (1885-1942), and dedicated student(s), such as Endo Moriya (1896-1950) remain the most likely candidates involved in the creation and development of gonosen-no-kata.

Efficacy of Health Surveillance and Polymerase Chain Reaction Testing in Judo During the COVID-19 Pandemic.

Background The COVID-19 pandemic necessitated infection control for all sporting activities. More careful infection control measures are required in judo, where close contact with opponents cannot be avoided. The Medical Science Committee of the All Japan Judo Federation (AJJF) established infection control guidelines for daily practice and competitions. Infection control measures were also implemented at the national tournament organized by the AJJF. Objective and methods This study aimed to examine the effectiveness of pre-tournament health surveys and PCR testing in guidelines for judo tournaments. Participants had to complete a health survey one to two weeks before the tournament. Initially, PCR testing was performed on all athletes; however, the final policy was to conduct PCR testing only on athletes with an infected person (risk team testing method). The effectiveness of these methods was also examined. Results In 16 competitions between October 2020 and March 2023, 6980 contestants were registered, and PCR testing was performed on 3672 athletes; 29 (0.79%) had a positive PCR test. Only two contestants were unable to attend the tournament because of the health survey. No competition-related cluster outbreaks were observed. From May 2022, the competition was held under the guideline that only teams at risk of infection were tested and could only compete when they tested negative. No teams were tested according to this guideline. In the competitions organized within this guideline, only one person could not compete because of the information provided in the health survey. No clusters were observed in any of the competitions. The incidence of COVID-19 infection in the first week after the convention was 20 (0.60%) in testing only at-risk teams and 21 (0.57%) in testing all competitors, which was not significantly different.(p=0.62) Conclusion During the COVID-19 epidemic, health surveillance was necessary to prevent the registration of competitors at risk of infection prior to tournaments. If teams at risk of infection could be identified, PCR testing of all athletes might not be mandatory, and competitions could be organized safely. The Judoinfectious disease control guidelines we have developed might be used for other contact sports in the future when other infectious diseases are prevalent.

Epidemiology of Injuries during Judo Tournaments.

To determine the injury incidence proportion, distribution of injuries by anatomical location; injury type; injury severity, time loss; mechanism and situations of injuries; and the relative risk of injuries by gender, age, and weight categories during judo tournaments. Study Design. It is a systematic review. Data Sources. A systematic review of the literature was conducted via searches in PubMed, EMBASE, Web of Science, CINAHL, SPORTDiscus, Google Scholar, and PEDro. Eligibility Criteria. All original studies on the incidence of injuries during judo tournaments were included. Twenty-five studies were included out of the 1979 studies. Using the modified AXIS tool score for quality assessment, seven were rated as having good quality, nine were rated as having fair quality, and four were rated as having poor quality. The injury incidence proportion during tournaments ranged from 2.5% to 72.5% for injuries requiring medical evaluation and 1.1% to 4.1% for injuries causing time loss (i.e., inability to continue game participation). The most commonly reported injury location was the head, followed by the hand, knee, elbow, and shoulder. The most frequent types of injury were sprains, followed by contusions, skin lacerations, strains, and fractures. In judo tournaments, injuries were more often sustained during standing fights (tachi-waza) than in ground fights (ne-waza). The tournament injury incidence proportion ranged from 2.5% to 72.5% for injuries requiring medical attention and 1.1% to 4.1% for injuries causing time loss. The head was the most frequently injured body part, and sprain was the most frequent injury type. However, current reports on injuries during judo tournaments are heterogeneous and inconsistent, limiting our understanding of in-match injury risks. Future studies should utilize the guidelines of the International Olympic Committee consensus meeting statement on the methodological approach to injury reporting. We recommend a judo-specific extension of this statement to fit the unique features of judo sports practice.

Injury Symmetry in Judo

Background: Each combat sport carries different risks of injury due to the specifics of the sport (including the weight categories and sex) and the fighting techniques used according to different sports regulations. The purpose of this study is to examine injury symmetry in judo. Methods: Injuries recorded in 195 people (93 women, 102 men) suffered during top-level judo tournaments were verified. Using the European Judo Union medical questionnaire, information on injuries was obtained from each injured athlete. Results: Based on the analysis of the results, it can be concluded that injuries are almost evenly distributed on the left and right sides of the body in both men and women. In women, there were 129 injuries to the left side (41.2%), 134 injuries to the right (42.8%), and 50 (16.0%) to the middle part of the body. Conclusions: injuries in judo are evenly distributed and slightly more common on the right side. Injuries occur at a greater rate during defending maneuvers than attacking maneuvers in judo. Identification and monitoring of who (tori or uke) and which side of the body sustains an injury are crucial and important in injury prevention. This knowledge makes it possible to modify existing sports regulations by eliminating behaviors (e.g., certain types of defense) to improve the safety of athletes participating in top-level competitions and the training process in terms of ensuring safety in both attack and defense.

Impact of time-of-day on judo-specific performance

In judo tournaments, matches for each weight category are held on the same day and athletes competing at the finals have to compete at different times of the day. This study aimed to investigate the effect of time-of-day on judo specific performance and the changes in physiological load following judo specific performance. Fourteen male judo athletes (age 19.1±1.4 years) voluntarily participated in the study. At the 1st visit, anthropometrical measurements and familiarization procedures were conducted and the athletes’ chronotype was determined. Athletes performed the Special Judo Fitness Test (SJFT) during 2nd and 3rd visits. Athletes randomly performed two consecutive SJFTs with 15 min intervals at 10:00h, which is the official start time of matches, and at 18:00h which is the time when the finals start. During SJFT applications, athletes heart rate (HR), blood lactate (bLA), body temperature and rate of perceived exertion (RPE) were monitored. The changes in total throw numbers (F1, 13= 1.32, p=0.27) and SJFT index (F1, 13= 0.30, p=0.59) were not different between morning and evening. There were similar changes in bLA (F4, 52=0.66, p=0.63), RPE (F1, 13=1.42, p=0.26) and body temperature (F1.4, 18.0=1.18, p=0.31) which were measured before and after the tests. However, HR measured in the evening were higher compared to morning measurement at all measurement times (F1, 13=10.28, p=0.01), but there was no difference in SJFT throws (F3.8, 48.8=0.49, p=0.74). In conclusion, different times of the day did not affect judo specific performance as well as physiological variables in judo athletes.

일제강점기 한국유도의 민족사상을 통한 업적에 관해

This study examined and discussed the historical significance of the developmental aspects of the Kodokan Judo in the process of inflow of Kodokan Judo by forced suppression after the establishment of YMCA Judo in 1906 in Korea with an objective perspective and drew conclusions. The establishment of Judo Korea was officially established on November 22, 1917 by the forced suppression of the Chosun Judo Department in the YMCA Hwangseong Christian Youth Association in 1906. This group was a group by political means of the Chosun Governor-General and the Japanese imperialists.,On the other hand, the Judo part of the Joseon Dynasty formed a momentum for the commercial spirit in the Judo part of the YMCA Hwangseong Christian Youth Association for the sake of national revival. In other words, with the claim of Lee Sang-jae, a teacher of Vietnam, who is training 100 people in the terrible times of the Japanese colonial rule, the national leaders did not spare all physical support to inspire the business spirit through Judo first, and the indifference of the drama in the emerging military schools became the starting point for the independence movement. In addition, the first Judo tournament was held on October 19, 1929, with five organizations participating, but the last tournament was abolished by Japan on October 12, 1935, as the 7th meeting. However, Lee Sun-gil won the championship and runner-up in 1930s and 1940s, and Seok Jin-kyung not only won the solo exhibition of the Judo Championship in July 1933, but also the Chosun Judo re-defeated Japan and gave a national spirit of business as a country. Thus, it will be possible to present the historical value that achieved the grandeur through the national thought of Judo in Korea during the Japanese colonial period and the academic plan of Judo history education.

Stress Responses to One-Day Athletic Tournament in Sport Coaches: A Pilot Study.

Simple SummaryJudo coaches respond to stress during one-day tournaments, as evidenced by significant changes in hormonal status. The cumulative effect of stressful stimuli was noticeable especially at the end of the day. The results of the present study indicate the usefulness of using tools and a way to study stress among coaches. A similar research protocol can be used to assess stress responses to single-day stimuli associated with other social and occupational roles in healthy middle-aged men.Background: Watching athletic tournaments induces emotional and physiological responses in sports fans and coaches. The aim of the study was to investigate hormonal and cardiovascular responses in judo coaches observing the fights of their athletes during one-day, high-level tournaments. Material and methods: We studied the biological responses of a group of seventeen judo club coaches between the ages of 39 and 57 years to a one-day judo tournament attended by the adult male and/or female athletes that they coached. At the time of the tournaments and also in neutral conditions, the coaches’ capillary blood and saliva samples were collected concurrently two times a day, both at 7:30 a.m. and after completion of the tournament (at about 8:00 p.m.). Cardiovascular parameters were also determined at the same times of day. Sleep quality (SQ) was assessed on a 6-point scale both on the night preceding the tournament and in neutral conditions. Cortisol (C) and testosterone (T) levels were determined from serum and saliva samples. The results for both days at different times of day were compared. Results: Statistical calculations showed higher concentrations of cortisol and a greater reduction of testosterone levels in serum and saliva at the end of the day during the tournament compared with those on a neutral day. Morning and evening cardiovascular indices were higher during the tournament. Conclusion: The study showed that during one-day tournaments, judo coaches were exposed to stress that induced intermittent hormonal changes in blood and saliva and activated the autonomic nervous system.

The Efficacy of Health Surveys and Polymerase Chain Reaction Tests Prior to Judo Tournaments During the COVID-19 Pandemic.

BackgroundAs of October 2021, sports activities require preventive measures against coronavirus disease 2019 (COVID-19) infection. Judo, a close-contact sport, demands careful prevention with great consideration to the risk of infection. The All Japan Judo Federation Medical Science Committee (AJJF) designed COVID-19 prevention protocols from a medical perspective and developed policies for safe regular practices and tournaments.Objective and MethodsWe aim to examine the efficacy of health surveys and polymerase chain reaction (PCR) tests prior to judo tournaments, as mandated by the tournament policy. Infection prevention managers were installed prior to tournaments. Two weeks prior to each tournament, these managers drafted health inventory forms for athletes and related parties to check for COVID-19-associated symptoms. Although PCR testing prior to tournaments was not required by policy, the AJJF conducted them (directly and by mail) prior to six tournaments from October 2020 to September 2021 for athletes whose health inventory forms listed no symptoms.ResultsOne of the athletes was not tested and was unable to participate in a tournament due to the symptoms indicated in their health inventory form. Testing began in October 2020 and was conducted until September 2021 for 2,073 athletes over the duration of six tournaments. The SARS-CoV-2 virus was detected in 11 (0.29%) athletes. In tournaments held until April 2021, SARS-CoV-2 was detected in only one of the 1,173 (0.08%) athletes tested. However, prior to tournaments held from July 2021 onward, when variants became prevalent, SARS-CoV-2 was detected in 10 (1.1%) of the 900 athletes tested (p < 0.05). No clusters were reported in association with any tournament.ConclusionWe believe that drafting health inventory forms two weeks prior to judo tournaments was essential and kept the participants alert. However, as variants emerged, some participants who were positive could not be detected through their inventory forms; this demonstrates the need for caution when relying on health inventory forms alone.

BIOMEDICAL INDICATORS OF PRE-COMPETITIVE STRESS IN FEMALE AND MALE JUDO PLAYERS

The aim of the present paper is to monitor changes of selected mental and physiological stress indicators in both female and male sportsmen in the subsequent days prior to an International Judo Tournament in Poland and on the competition day. The study included 9 men and 9 women, participants of the training camp that ended with a tournament. Every morning, on the three consecutive days preceding the competition (day -3, -2, -1) and on the competition day (day 0) capillary blood was sampled to determine serum cortisol (C) and testosterone (T) levels, then the subjects assessed their night sleep quality (SQ) with the use of a 5-point Likert scale, and perceived anxiety using the State-Trait Anxiety Inventory questionnaire by Spielberger (STAI - Polish version). SQ insignificantly deteriorated, and C and anxiety levels increased with the time to event. The inter-group analysis for the entire period showed higher scores in average anxiety and higher average level of C in women than men. The relative changes in these biomarkers could indicate higher pre-competitive stress in women, however without taking into account the sports class of the opponents individually for each of the groups one cannot imply gender-specific susceptibility to stress as a general principle.

Effect of official judo matches on handgrip strength and perceptual responses.

This study aimed to verify the effect of judo matches on handgrip strength and perceptual responses during an official tournament in medalists and nonmedalists. Thirty-four male judo athletes participated in an official judo tournament. Before the first match and immediately after each match, maximum isometric handgrip strength and rate of perceived exertion overall and in specific areas were assessed. Analysis of variance for repeated measures was used to compare variables before the first match and after each match, and t-test was used to compare medalists and nonmedalists with the level of significance set at 5%. Also, effect size (ES) analysis was used. The results showed decrease in handgrip strength in both hands from the third match (P<0.05). The rate of perceived exertion (RPE) increased from the first match and remained high over the subsequent matches (P<0.001). A very large effect for nonmedalist group (ES=3.44) and large effect for medalist group (ES=1.94) was found in the third match compared to prematch. Forearm and fingers were the body regions most cited by athletes in both groups. We concluded that an official judo competition induced significant drop in handgrip strength from the third match and increased the RPE from first match. Medalists seem to have better recovery after the third match compared to nonmedalists.

Injury Profile and Risk Factors in a Young High Competitive Population of Judo Athletes

High competitive level judo practice from a very young age, may lead to an increasing risk of injury. The aim of this study is to identify injury risk factors in a young high-level judo population to develop future specific strategies for injury prevention. An individual questionnaire was applied by physicians to cadet and junior athletes that competed in international judo tournaments in 2014. Statistical inferential analysis was performed to identify the major injury risk factors and injury patterns in these ages.

Does Blue Uniform Color Enhance Winning Probability in Judo Contests?

The color of an athlete's uniform may have an effect on psychological functioning and consequently bias the chances of winning contests in sport competition. Several studies reported a winning bias for judo athletes wearing a blue outfit relative to those wearing a white outfit. However, we argue there is no winning bias and that previous studies were confounded and based on small and specific data sets. We tested whether blue biases winning in judo using a very extensive judo data set (45,874 contests from all international judo tournaments between 2008 and 2014). In judo, the first called athlete for the fight used to wear the blue judogi but this was changed to the white judogi in 2011. This switch enabled us to compare the win bias before and after this change to isolate the effect of the color of the judogi. We found a significant win bias for the first called athlete, but this effect was not significantly related to the color of the judogi. The lack of a significant win effect of judogi color suggests that blue does not bias winning in judo, and that the blue-white pairing ensures an equal level of play. Our study shows the importance of thoroughly considering alternative explanations and using extensive datasets in color research in sports and psychology.

On Heterogeneity, Weight Categories and Home Advantage in Professional Judo

Judo is a combat sport with seven different weight categories. In this paper, we examined data from 1,902 men’s and 1,400 women’s fights at the eight most prestigious judo tournaments during the period 2010-2013. Using a single fight as the unit of observation, we found that the probability for the favorite to win against the underdog in the men’s half-light weight category is significantly lower than in most other categories. Moreover, in fights in which only European and/or Asian judokas participate, we found that the men’s half-light weight category is significantly more balanced than all other men's categories. For women, there is no consistent evidence that any one weight category is more balanced than any of the others. Our results indicate that in choosing the members of a national team, it is to some extent reasonable for national coaches to select a lower ranked judoka in the men's half-light weight category over a higher ranked judoka in several other weight categories. We also found that the home advantage increases the probability of winning a single fight for both genders. This result implies that it might be worthwhile for national judo associations to bid to host international tournaments in order to improve the world rankings of their domestic judokas.

On Winning Probabilities, Weight Categories, and Home Advantage in Professional Judo

Judo is a combat sport with seven different weight categories. In this article, we examined data from 1,902 men’s and 1,400 women’s fights at the eight most prestigious judo tournaments during the period 2010-2013. Using a single fight as the unit of observation, we found that the probability for the favorite to win against the underdog in the men’s half-lightweight category is significantly lower than in most other categories. Moreover, in fights in which only European and/or Asian judokas participate, we found that the men’s half-lightweight category is significantly more balanced than all other men’s categories. For women, there is no consistent evidence that any one weight category is more balanced than any of the others. Our results indicate that in choosing the members of a national team, it is to some extent reasonable for national coaches to select a lower ranked judoka in the men’s half-lightweight category over a higher ranked judoka in several other weight categories. We also found that the home advantage increases the probability of winning a single fight for both genders. This result implies that it might be worthwhile for national judo associations to bid to host international tournaments in order to improve the world rankings of their domestic judokas.

Analysis of the final fights of the judo tournament at Rio 2016 Olympic Games

Analysis of the final fights of the judo tournament at Rio 2016 Olympic Games

Intensity of perceived stress prior to a judo tournament among male and female contestants. A preliminary study

Intensity of perceived stress prior to a judo tournament among male and female contestants. A preliminary study

One of the consideration concerning testing induction of the IJF new rules.-An object of study in the Teizo Kawamura cup judo tournament for high-school students.-

One of the consideration concerning testing induction of the IJF new rules.<BR>-An object of study in the Teizo Kawamura cup judo tournament for high-school students.-

Techniques frequently used during London Olympic judo tournaments: a biomechanical approach

Feedback between training and competition should be considered in athletic training. The aim of the study was contemporary coaching tendencies in women’s and men’s judo with particular focus on a biomechanical classification of throws and grappling actions. 359 throws and 77 grappling techniques scored by male and female athletes in Olympic Judo Tournaments (London 2012) have been analyzed. Independence of traits (gender and weight category by technique classes) was verified via c2 test. Comparison between frequency of each subsequent technique class and rest/inconclusive counts was made in 2×2 contingency tables. The significance level was set at p£0.05. Throwing technique frequencies grouped in the seven biomechanical classes were dependent on gender. A significant difference was found between frequencies of variable arm of physical lever technique scored by males (27.09%) and females (16.67%) as compared to the rest/inconclusively techniques counts. Significant differences between men who competed in extra lightweight and heavy weight concerned the frequency of the techniques used with maximum arm or variable arm of physical lever and a couple of forces applied by trunk and legs. In females, a tendency to higher frequency of techniques that used couple of forces applied by arm or arms and leg was observed in extra lightweight compared to the heavy weight. Because the technique preferred in the fight depends on a gender and weight category of a judoka, the relationships found in this study, which can be justified by the biomechanics of throws, should be taken into consideration in technical and tactical coaching of the contestants. A method used in this study can be recommended for future research concerning coaching tendencies.

Analysis of fighting actions of judo competitors on the basis of the men’s tournament during the 2008 Olympic Games in Beijing

Summary Introduction. The aim of this work was to provide a characteristics of the judo combat and present factors that may influence the result of a sports combat. On the basis of the tournament’s result analysis, the combat specifics of the world’s top athletes were determined and may be used to orient and streamline a training process. Material and methods. The study materials were the combat lists from the men’s judo tournament in Beijing as published on the official website of the Olympic Games. The indirect observation method was applied, using computerised and available information concerning each combat. Basic statistical methods were used to process the data: arithmetic means and percentage compilation. Results. During the men’s tournament, there was a total of 303 combats in all 7 weight categories. Altogether, there were 228 competitors participating. No country gained a clear advantage in the medal classification. A significant part of combats (66.67%) ended by nage-waza (throwing), of which the te-waza (hand) (27.06%) and ashi-waza (foot and leg) (23.43%) techniques most often decided about the victory. The katame-waza (grappling) techniques ended 15.51% of all combats. Out of all 47 combats that ended in a horizontal position, 37 ended by osaekomi-waza (holding). Conclusions. 1. Most combats of the men’s tournament ended before time and the score awarded most often by referees was ippon. 2. The victories were most often awarded in consequence of the nage-waza (throwing) techniques rather than the katame–waza (grappling) techniques. 3. The te-waza (hand) throwing group techniques proved to be dominating.

No effect of blue on winning contests in judo

A study by Rowe et al. reported a winning bias for judo athletes wearing a blue outfit relative to those wearing a white one during the 2004 Olympics. It was suggested that blue is associated with a higher likelihood of winning through differential effects of colour on opponent visibility and/or an intimidating effect on the opponent. However, we argue that there is no colour effect on winning in judo. We show that alternative factors, namely allocation biases, asymmetries in prior experience and differences in recovery time are possible confounding factors in the analysis of Rowe et al. After controlling for these factors, we found no difference in blue and white wins. We further analysed contest outcomes of 71 other major judo tournaments and also found no winning bias. Our findings have implications for sports policy makers: they suggest that a white-blue outfit pairing ensures an equal level of play.