|Country of origin||Japan|
|Famous practitioners||Tsunejiro Tomita, Theodore Roosevelt, Shiro Saigo, Mitsuo Maeda, Kyuzo Mifune, Keiko Fukuda, Masahiko Kimura, Gene LeBell, Gokor Chivichyan, Fedor Emelianenko, Anton Geesink, Yasuhiro Yamashita, Erik Paulson, Neil Adams, Hidehiko Yoshida, Yoshihiro Akiyama, Dong Hyun Kim, David Douillet, Kosei Inoue, Teddy Riner, AnnMaria De Mars, Jimmy Pedro, Vladimir Putin, Ronda Rousey, Donnie Yen, Anderson Silva, Gegard Mousasi, Bas Rutten, Norman Parke, Kayla Harrison|
|Parenthood||Various koryū Jujutsu schools, principally Tenjin Shin'yō-ryū and Kito-ryū|
|Descendant arts||Brazilian jiu-jitsu, Kosen judo, Sambo, Nippon Kempo|
|Olympic sport||Since 1964 (men) and 1992 (women)|
|Official website||International Judo Federation (IJF)
Judo (柔道 jūdō?, meaning "gentle way") is a modern martial art, combat and Olympic sport created in Japan in 1882 by Jigoro Kano (嘉納治五郎). Its most prominent feature is its competitive element, where the objective is to either throw or takedown an opponent to the ground, immobilize or otherwise subdue an opponent with a pin, or force an opponent to submit with a joint lock or a choke. Strikes and thrusts by hands and feet as well as weapons defenses are a part of judo, but only in pre-arranged forms (kata, 形) and are not allowed in judo competition or free practice (randori, 乱取り). A judo practitioner is called a judoka.
The philosophy and subsequent pedagogy developed for judo became the model for other modern Japanese martial arts that developed from koryū (古流?, traditional schools). The worldwide spread of judo has led to the development of a number of offshoots such as Sambo and Brazilian jiu-jitsu.
- 1 History and philosophy
- 2 Judo waza (techniques)
- 3 Pedagogy
- 4 Competitive judo
- 5 In mixed martial arts
- 6 Related arts and derivatives
- 7 Safety
- 8 Judoka (practitioner)
- 9 Judogi (uniform)
- 10 Organizations
- 11 Rank and grading
- 12 See also
- 13 Footnotes
- 14 Bibliography
- 15 External links
- 16 Research articles
History and philosophy
Early life of the founder
The early history of judo is inseparable from its founder, Japanese polymath and educator Jigoro Kano (嘉納 治五郎 Kanō Jigorō?, 1860–1938), born Shinnosuke Kano (嘉納 新之助 Kanō Shinnosuke?). Kano was born into a relatively affluent family. His father, Jirosaku, was the second son of the head priest of the Shinto Hiyoshi shrine in Shiga Prefecture. He married Sadako Kano, daughter of the owner of Kiku-Masamune sake brewing company and was adopted by the family, changing his name to Kano, and ultimately became an official in the Bakufu government.
Jigoro Kano had an academic upbringing and, from the age of seven, he studied English, Japanese calligraphy (書道 shodō?) and the Four Confucian Texts (四書 Shisho?) under a number of tutors. When he was fourteen, Kano began boarding at an English-medium school, Ikuei-Gijuku in Shiba, Tokyo. The culture of bullying endemic at this school was the catalyst that caused Kano to seek out a Jujutsu (柔術 Jūjutsu?) dojo (道場 dōjō?, training place) at which to train.
Early attempts to find a jujutsu teacher who was willing to take him on met with little success. With the fall of the Tokugawa shogunate in the Meiji Restoration of 1868, jujutsu had become unfashionable in an increasingly westernised Japan. Many of those who had once taught the art had been forced out of teaching or become so disillusioned with it that they had simply given up. Nakai Umenari, an acquaintance of Kanō's father and a former soldier, agreed to show him kata, but not to teach him. The caretaker of his father's second house, Katagiri Ryuji, also knew jujutsu, but would not teach it as he believed it was no longer of practical use. Another frequent visitor to Kanō's father's house, Imai Genshiro of Kyūshin-ryū (扱心流?) school of jujutsu, also refused. Several years passed before he finally found a willing teacher.
In 1877, as a student at the Tokyo-Kaisei school (soon to become part of the newly founded Tokyo Imperial University), Kano learned that many jujutsu teachers had been forced to pursue alternative careers, frequently opening Seikotsu-in (整骨院?, traditional osteopathy practices). After inquiring at a number of these, Kano was referred to Fukuda Hachinosuke (c.1828–1880), a teacher of the Tenjin Shin'yō-ryū (天神真楊流?) of jujutsu, who had a small nine mat dojo where he taught five students. Fukuda is said to have emphasized technique over formal exercise, sowing the seeds of Kano's emphasis on randori (乱取り randori?, free practice) in judo.
On Fukuda's death in 1880, Kano, who had become his keenest and most able student in both randori and kata (形 kata?, pre-arranged forms), was given the densho (伝書?, scrolls) of the Fukuda dojo. Kano chose to continue his studies at another Tenjin Shin'yō-ryū school, that of Iso Masatomo (c.1820–1881). Iso placed more emphasis on the practice of kata, and entrusted randori instruction to assistants, increasingly to Kano. Iso died in June 1881 and Kano went on to study at the dojo of Iikubo Tsunetoshi (1835–1889) of Kitō-ryū (起倒流?). Like Fukuda, Iikubo placed much emphasis on randori, with Kitō-ryū having a greater focus on nage-waza (投げ技?, throwing techniques).
Founding of the Kodokan
In February 1882, Kano founded a school and dojo at the Eisho-ji (永昌寺?), a Buddhist temple in what was then the Shitaya ward of Tokyo (now the Higashi Ueno district of Taitō ward). Iikubo, Kano's Kitō-ryū instructor, attended the dojo three days a week to help teach and, although two years would pass before the temple would be called by the name Kodokan (講道館 Kōdōkan?, "place for expounding the way"), and Kano had not yet received his Menkyo (免許?, certificate of mastery) in Kitō-ryū, this is now regarded as the Kodokan founding.
The Eisho-ji dojo was a relatively small affair, consisting of a twelve mat training area. Kano took in resident and non-resident students, the first two being Tsunejiro Tomita and Shiro Saigo. In August, the following year, the pair were granted shodan (初段?, first rank) grades, the first that had been awarded in any martial art.
Judo versus Jujutsu
Central to Kano's vision for judo were the principles of seiryoku zen'yō (精力善用?, maximum efficiency, minimum effort) and jita kyōei (自他共栄?, mutual welfare and benefit). He illustrated the application of seiryoku zen'yō with the concept of jū yoku gō o seisu (柔よく剛を制す?, softness controls hardness):
In short, resisting a more powerful opponent will result in your defeat, whilst adjusting to and evading your opponent's attack will cause him to lose his balance, his power will be reduced, and you will defeat him. This can apply whatever the relative values of power, thus making it possible for weaker opponents to beat significantly stronger ones. This is the theory of ju yoku go o seisu.
Kano realised that seiryoku zen'yō, initially conceived as a Jujutsu concept, had a wider philosophical application. Coupled with the Confucianist-influenced jita kyōei, the wider application shaped the development of judo from a martial art (武術 bujutsu?) to a martial way (武道 budō?). Kano rejected techniques that did not conform to these principles and emphasised the importance of efficiency in the execution of techniques. He was convinced that practice of Jujutsu while conforming to these ideals was a route to self-improvement and the betterment of society in general. He was, however, acutely conscious of the Japanese public's negative perception of Jujutsu:
At the time a few bujitsu (martial arts) experts still existed but bujitsu was almost abandoned by the nation at large. Even if I wanted to teach jujitsu most people had now stopped thinking about it. So I thought it better to teach under a different name principally because my objectives were much wider than jujitsu.
Kano believed that "Jūjutsu" was insufficient to describe his art: although Jutsu (術?) means "art" or "means", it implies a method consisting of a collection of physical techniques. Accordingly, he changed the second character to dō (道?), meaning way, road or path, which implies a more philosophical context than jutsu and has a common origin with the Chinese concept of tao. Thus Kano renamed it judo (柔道 Jūdō?).
Judo waza (techniques)
There are three basic categories of waza (技?, techniques) in judo: nage-waza (投げ技?, throwing techniques), katame-waza (固技?, grappling techniques) and atemi-waza (当て身技?, striking techniques). Judo is most known for nage-waza and katame-waza.
Judo practitioners typically devote a portion of each practice session to ukemi (受け身?, break-falls), in order that nage-waza can be practiced without significant risk of injury. Several distinct types of ukemi exist, including ushiro ukemi (後ろ受身?, rear breakfalls); yoko ukemi (横受け身?, side breakfalls); mae ukemi (前受け身?, front breakfalls); and zenpo kaiten ukemi (前方回転受身?, rolling breakfalls)
Nage waza (throwing techniques)
Nage waza include all techniques in which tori attempts to throw or trip uke, usually with the aim of placing uke on his back. Each technique has three distinct stages:
- Kuzushi (崩し?), the initial balance break;
- Tsukuri (作り?), the act of turning in and fitting into the throw;
- Kake (掛け?), the execution and completion of the throw.
Traditionally, nage waza are further categorised into tachi-waza (立ち技?, standing techniques), throws that are performed with tori maintaining an upright position, and sutemi-waza (捨身技?, sacrifice techniques), throws in which tori sacrifices his upright position in order to throw uke.
Tachi-waza are further subdivided into te-waza (手技?, hand techniques), in which tori predominantly uses his arms to throw uke; koshi-waza (腰技?, hip techniques) throws that predominantly use a lifting motion from the hips; and ashi-waza (足技?, foot and leg techniques), throws in which tori predominantly utilises his legs.
foot and leg techniques
rear sacrifice techniques
side sacrifice techniques
Katame-waza (grappling techniques)
Katame-waza is further categorised into osaekomi-waza (押込技?, holding techniques), in which tori traps and pins uke on his back on the floor; shime-waza (絞技?, strangulation techniques), in which tori attempts to force a submission by choking or strangling uke; and kansetsu-waza (関節技?, joint techniques), in which tori attempts to submit uke by painful manipulation of his joints.
In competitive judo, Kansetsu-waza is currently limited to elbow joint manipulation. Manipulation and locking of other joints can be found in various kata, such as Katame-no-kata and Kodokan goshin jutsu.
holding or pinning techniques
Joint techniques (locks)
Atemi-waza (striking techniques)
Atemi-waza are techniques in which tori disables uke with a strike to a vital point. Atemi-waza are not permitted outside of kata.
Randori (free practice)
Judo pedagogy emphasizes randori (乱取り?, literally "taking chaos", but meaning "free practice"). This term covers a variety of forms of practice, and the intensity at which it is carried out varies depending on intent and the level of expertise of the participants. At one extreme, is a compliant style of randori, known as Yakusoku geiko (約束稽古?, prearranged practice), in which neither participant offers resistance to their partner's attempts to throw. A related concept is that of Sute geiko (捨稽古?, throw-away practice), in which an experienced judoka allows himself to be thrown by his less-experienced partner. At the opposite extreme from yakusoku geiko is the hard style of randori that seeks to emulate the style of judo seen in competition. While hard randori is the cornerstone of judo, over-emphasis of the competitive aspect is seen as undesirable by traditionalists if the intent of the randori is to "win" rather than to learn.
Randori is usually limited to either tachi waza (standing techniques) or ne waza (ground work) and, when one partner is thrown in tachi waza randori, practice is resumed with both partners on their feet.
Kata (形 kata?, Forms) are pre-arranged patterns of techniques and in judo, with the exception of the Seiryoku-Zen'yō Kokumin-Taiiku, they are all practised with a partner. Their purposes include illustrating the basic principles of judo, demonstrating the correct execution of a technique, teaching the philosophical tenets upon which judo is based, allowing for the practice of techniques that are not allowed in randori, and to preserve ancient techniques that are historically important but are no longer used in contemporary judo.
There are ten kata that are recognized by the Kodokan today:
- Randori-no-kata (乱取りの形?, Free practice forms), comprising two kata:
- Nage-no-kata (投の形?, Forms of throwing) Fifteen throws, practiced both left- and right-handed, three each from the five categories of nage waza: te waza, koshi waza, ashi waza, ma sutemi waza and yoko sutemi waza.
- Katame-no-kata (固の形?, Forms of grappling or holding). Fifteen techniques in three sets of five, illustrating the three categories of katame waza: osaekomi waza, shime waza and kansetsu waza.
- Kime-no-kata (極の形?, Forms of decisiveness). Twenty techniques, illustrating the principles of defence in a combat situation, performed from kneeling and standing positions. Attacks are made unarmed and armed with a dagger and a sword. This kata utilises atemi waza, striking techniques, that are forbidden in randori.
- Kōdōkan goshinjutsu (講道館護身術?, Kodokan skills of self-defence). The most recent recognised kata, comprising twenty-one techniques of defence against attack from an unarmed assailant and one armed with a knife, stick and pistol. This kata incorporates various jujutsu techniques such as wrist locks and atemi waza.
- Jū-no-kata (柔の形?, Forms of gentleness & flexibility). Fifteen techniques, arranged in three sets of five, demonstrating the principle of Jū and its correct use in offence and defence.
- Gō-no-kata (剛の形?, Forms of force). One of the oldest kata, comprising ten forms that illustrate the efficient use of force and resistance. Now rarely practiced.
- Itsutsu-no-kata (五の形?, The five forms). An advanced kata, illustrating the principle of seiryoku zen'yō and the movements of the universe. Recent research has shown that this kata, unlike what often has been claimed, was not created by Kano, but similar to Koshiki-no-kata, it was merely imported into judo after Kano slightly amended it. The kata predates the creation of Kodokan and comes from Tenjin Shinyō-ryū.
- Koshiki-no-kata (古式の形?, Traditional forms). Derived from Kitō-ryū Jujutsu, this kata was originally intended to be performed wearing armour. Kano chose to preserve it as it embodied the principles of judo.
- Seiryoku Zen'yō Kokumin Taiiku (精力善用国家体育?, Maximum-efficiency national physical education). A series of exercises designed to develop the physique for judo.
- Joshi-goshinhō (女性護身法?, Methods of self-defence for women). An exercise completed in 1943, and of which the development was ordered by Jiro Nango, the second Kodokan president.
In addition, there are a number of commonly practiced kata that are not recognised by the Kodokan. Some of the more common kata include:
- Go-no-sen-no-kata (後の先の形?) A kata of counter techniques developed at Waseda University in Tokyo, popularised in the West by Mikonosuke Kawaishi.
- Nage-waza-ura-no-kata (投げ技裏の形?) Another kata of counter techniques, created by Kyuzo Mifune.
- Kaeshi-no-kata (返の形?, Forms of return) Yet another kata of counters, attributed to Yukio Tani
History of competitive judo
Contest (試合 shiai or jiai with rendaku?) is a vitally important aspect of judo. Early examples include the Kodokan Monthly Tournament (月次試合 Tsukinami jiai?) and the biannual Red and White Tournament (紅白試合 Kohaku jiai?), both of which started in 1884 and continue to the present day.
In 1899, Kano was asked to chair a committee of the Dai Nippon Butoku Kai to draw up the first formal set of contest rules for jujutsu. These rules were intended to cover contests between different various traditional schools of jujutsu as well as practitioners of Kodokan judo. Contests were 15 minutes long and were judged on the basis of nage waza and katame waza, excluding atemi waza. Wins were by two ippons, awarded in every four-main different path of winning alternatives, by "Throwing", where the opponent's back strikes flat onto the mat with sufficient force, by "Pinning" them on their back for a "sufficient" amount of time, or by Submission, which could be achieved via "Shime-waza" or "Kansetsu-waza", in which the opponent was forced to give himself or herself up or summon a referee's or corner-judge's stoppage. Finger, toe and ankle locks were prohibited. In 1900, these rules were adopted by the Kodokan with amendments made to prohibit all joint locks for kyu grades and added wrist locks to the prohibited kansetsu-waza for dan grades. It was also stated that the ratio of tachi-waza to ne-waza should be between 70% to 80% for kyu grades and 60% to 70% for dan grades.
In 1916, additional rulings were brought in to further limit kansetsu waza with the prohibition of ashi garami and neck locks, as well as do jime. These were further added to in 1925, in response to Kosen judo (高專柔道 Kōsen jūdō?), which concentrated on ne waza at the expense of tachi waza. The new rules banned all remaining joint locks except those applied to the elbow and prohibited the dragging down of an opponent to enter ne waza.
The All-Japan Judo Championships (全日本柔道選手権大会 Zennihon jūdō senshuken taikai?) were first held in 1930 and have been held every year, with the exception of the wartime period between 1941 and 1948, and continue to be the highest profile tournament in Japan.
Judo's international profile was boosted by the introduction of the World Judo Championships in 1956. The championships were initially a fairly small affair, with 31 athletes attending from 21 countries in the first year. Competitors were exclusively male until the introduction of the Women's Championships in 1980, which took place on alternate years to the Men's Championships. The championships were combined in 1987 to create an event that takes place annually, except for the years in which Olympic games are held. Participation has steadily increased such that, in the most recent championships in 2011, 871 competitors from 132 countries took part.
The first time judo was seen in the Olympic Games was in an informal demonstration hosted by Kano at the 1932 Games. However, Kano was ambivalent about judo's potential inclusion as an Olympic sport:
I have been asked by people of various sections as to the wisdom and possibility of judo being introduced with other games and sports at the Olympic Games. My view on the matter, at present, is rather passive. If it be the desire of other member countries, I have no objection. But I do not feel inclined to take any initiative. For one thing, judo in reality is not a mere sport or game. I regard it as a principle of life, art and science. In fact, it is a means for personal cultural attainment. Only one of the forms of judo training, so-called randori or free practice can be classed as a form of sport. Certainly, to some extent, the same may be said of boxing and fencing, but today they are practiced and conducted as sports. Then the Olympic Games are so strongly flavored with nationalism that it is possible to be influenced by it and to develop "Contest Judo", a retrograde form as ju-jitsu was before the Kodokan was founded. Judo should be free as art and science from any external influences, political, national, racial, and financial or any other organized interest. And all things connected with it should be directed to its ultimate object, the "Benefit of Humanity". Human sacrifice is a matter of ancient history.
Nevertheless, judo became an Olympic sport for men in the 1964 Games in Tokyo. The Olympic Committee initially dropped judo for the 1968 Olympics, meeting protests. Dutchman Anton Geesink won the first Olympic gold medal in the open division of judo by defeating Akio Kaminaga of Japan. The women's event was introduced at the Olympics in 1988 as a demonstration event, and an official medal event in 1992. Paralympic judo has been a Paralympic sport (for the visually impaired) since 1988; it is also one of the sports at the Special Olympics.
Current international contest rules
The traditional rules of judo are intended to provide a basis under which to test skill in judo, while avoiding significant risk of injury to the competitors. Additionally, the rules are also intended to enforce proper reigi (礼儀?, etiquette).
Penalties may be given for: passivity or preventing progress in the match; for safety infringements for example by using prohibited techniques, or for behavior that is deemed to be against the spirit of judo. Fighting must be stopped if a participant is outside the designated area on the mat.
There are currently seven weight divisions, subject to change by governing bodies, and may be modified based on the age of the competitors:
|Men||Under 60 kg||60–66 kg||66–73 kg||73–81 kg||81–90 kg||90–100 kg||Over 100 kg|
|Women||Under 48 kg||48–52 kg||52–57 kg||57–63 kg||63–70 kg||70–78 kg||Over 78 kg|
A throw that places the opponent on his back with impetus and control scores an ippon (一本?), winning the contest. A lesser throw, where the opponent is thrown onto his back, but with insufficient force to merit an ippon, scores a waza-ari (技あり?). Two scores of waza-ari equal an ippon (技あり合わせて一本 waza-ari awasete ippon?). A throw that places the opponent onto his side scores a yuko (有効?). No amount of yukos equal a waza-ari, they are only considered in the event of an otherwise tied contest.
Ippon is scored in ne-waza for pinning an opponent on his back with a recognised osaekomi-waza for 20 seconds or by forcing a submission through shime-waza or kansetsu-waza. A submission is signalled by tapping the mat or the opponent at least twice with the hand or foot, or by saying maitta (まいった?, I surrender). A pin lasting for less than 20 seconds, but more than 15 seconds scores waza-ari and one lasting less than 15 seconds but more than 10 seconds scores a yuko.
If the scores are identical at the end of the match, the contest is resolved by the Golden Score rule. Golden Score is a sudden death situation where the clock is reset to match-time, and the first contestant to achieve any score wins. If there is no score during this period, then the winner is decided by Hantei (判定?), the majority opinion of the referee and the two corner judges.
There have been changes to the scoring. In January 2013, the Hantei was removed and the "Golden Score" no longer has a time limit. The match would continue until a judoka scored through a technique or if the opponent is penalised (Shido).
Minor rules infractions are penalised with a shido (指導?, literally "guidance"). This is treated as a warning and anything up to three shidos make no contribution to the overall score. A fourth shido or serious rules violation yields a hansoku make (反則負け?, literally "foul-play defeat"), resulting in disqualification of the penalised competitor.
Formerly, there were two additional levels of penalty between shido and hansoku make: chui (注意?, literally "caution"), equivalent to a yuko and keikoku (警告?, literally "warning") equivalent to waza-ari.
Representation of scores
Judo scoreboards show the number of waza-ari and yuko scores scored by each player. (A score of koka was also displayed until its use was abandoned in 2009.) Often an ippon is not represented on the scoreboard, because upon award of an ippon the match is immediately terminated. Some computerized scoreboards will briefly indicate that an ippon has been scored.
Scoreboards normally also show the number of penalties imposed on each player, and sometimes the number of medical visits for each. (Only two "medical" attentions are allowed for each competitor during a match—most often for minor bleeds.)
Electronic scoreboards also usually include timers for measuring both competition time and osaekomi time.
In mixed martial arts
Several judo practitioners have made an impact in mixed martial arts. Notable judo trained MMA fighters include Olympic medalists Hidehiko Yoshida (Gold, 1992), Naoya Ogawa (Silver, 1992), Pawel Nastula (Gold, 1996), Makoto Takimoto (Gold, 2000), Satoshi Ishii (Gold, 2008) and Ronda Rousey (Bronze, 2008), former Russian national judo championship Bronze medalist Fedor Emelianenko, Karo Parisyan, Antonio Silva, Rick Hawn, Hector Lombard, Yoshihiro Akiyama and Dong-Sik Yoon.
Judo has been one of the primary martial arts displayed in Mixed Martial Arts (MMA) competitions since MMA’s inception.
The first official MMA fight, the Ultimate Fighting Championship (UFC), was held in 1993. It was advertised as a “no holds barred” fight. At the time, the public perception was that a larger/stronger human could dominate a smaller/weaker human. The fighters came from various martial arts or sports fighting backgrounds, including judo, karate, jiu-jitsu, boxing, wrestling, tae kwon do and kickboxing. They fought until the opponent was knocked out, tapped out (stopping the fight by tapping their hand), or the referee stopped the fight. The winner of the first Ultimate Fighting Championship was a small Brazilian, Royce Gracie, who used judo/Jujitsu submissions to defeat opponents twice his size 
Many MMA fights are ended by submission holds most of which derive from judo. “Chokeholds are common in Jujitsu, judo and submission grappling, and most trainers discuss how fighter need to experience these techniques in order to learn how to resist them” 
“Judo resembles MMA's grappling aspects, particularly when both fighters are on the ground. MMA fans would easily recognize judo's submissions -- a fighter might "tap out," or concede the fight, when caught in a chokehold or an armbar” 
Brazilian jiu-jitsu is derived from Judo, which was brought to Brazil by Esai Maeda, but with reduced emphasis on throws and increased emphasis on groundwork and submissions compared to modern Judo.
The Japanese found judo superior to Japanese Jujitsu due to proof in competition where it involved both stand up and grappling techniques. After a match-up between older styles of ju-jitsu and judo at the Tokyo police headquarters, judo was named the national martial art in Japan. It was the official art used by law enforcement in the late 1800s, and continues to be popular to this day. During World War II, many U.S. soldiers were exposed to the art of judo and brought it back to America with them. The first issue of Black Belt magazine in America (1961) featured a sketch of a judo throw and was a special judo issue” 
Ronda Rousey, a female MMA champion, won a bronze medal in judo at the 2008 Olympics. “Rousey eventually got an offer to try MMA and had her first professional fight in 2011. She has since defeated all but two of her opponents with a judo arm lock and is now a champion in the combat sport”.
Related arts and derivatives
Kano Jigoro's Kodokan judo is the most popular and well-known style of judo, but is not the only one. The terms judo and jujutsu were quite interchangeable in the early years, so some of these forms of judo are still known as jujutsu or jiu-jitsu either for that reason, or simply to differentiate them from mainstream judo. From Kano's original style of judo, several related forms have evolved—some now widely considered to be distinct arts:
- Brazilian jiu-jitsu: In 1914, Mitsuyo Maeda introduced judo to Brazil. Maeda taught judo to Carlos Gracie (1902–1994) and others in Brazil. The Gracie family named their development of judo 'Gracie jiu-jitsu'. This style emphasized the newaza aspects of judo and retains many of the kansetsu waza that were subsequently prohibited in competitive judo. Brazilian jiu-jitsu was popularized worldwide following its success in high profile mixed martial arts tournaments in the 1990s.
- Kosen judo (高專柔道?): Sometimes erroneously described as a separate style of judo, Kosen judo is a competition rules set of Kodokan judo that was popularized in the early 20th century for use in Japanese Special High Schools Championships held at Kyoto Imperial University. The word "Kosen" is an acronym of Koto Senmon Gakko (高等専門学校?, literally "Higher Professional School"). Kosen judo's focus on newaza has drawn comparisons with Brazilian jiu-jitsu.
- Russian judo: This distinctive style of judo was influenced by Sambo. It is represented by well-known coaches such as Alexander Retuinskih and Igor Yakimov, and mixed martial arts fighters such as Fedor Emelianenko and Karo Parisyan. In turn, Russian judo has influenced mainstream judo, with techniques such as the flying armbar being accepted into Kodokan judo.
- Sambo (especially Sport Sambo): Vasili Oshchepkov was the first European judo black belt under Kano. Oshchepkov went on to contribute his knowledge of judo as one of the three founders of Sambo, which also integrated various international and Soviet bloc wrestling styles and other combative techniques. Oshchepkov died during the political purges of 1937. In their History of Sambo, Brett Jacques and Scott Anderson wrote that in Russia "judo and SOMBO were considered to be the same thing"—albeit with a different uniform and some differences in the rules.
Kano's vision for judo was one of a martial way that could be practiced realistically. Randori (free practice) was a central part of judo pedagogy and shiai (competition) a crucial test of a judoka's understanding of judo. Safety necessitated some basic innovations that shaped judo's development. Atemi waza (striking techniques) were entirely limited to kata (prearranged forms) early in judo's history. Kansetsu waza (joint manipulation techniques) were limited to techniques that focused on the elbow joint. Various throwing techniques that were judged to be too dangerous to practice safely were also prohibited in shiai. To maximise safety in nage waza (throwing techniques), judoka trained in ukemi (break falls) and practiced on tatami (rice straw mats).
Kansetsu and shime waza
The application of joint manipulation and strangulation/choking techniques is generally safe under controlled conditions typical of judo dojo and in competition. It is usual for there to be age restrictions on the practice and application of these types of techniques, but the exact nature of these restrictions will vary from country to country and from organization to organization.
Safety in the practice of throwing techniques depends on the skill level of both tori and uke. Inexpertly applied throws have the potential to injure both tori and uke, for instance when tori compensates for poor technique by powering through the throw. Similarly, poor ukemi can result in injury, particularly from more powerful throws that uke lacks the skill to breakfall from. For these reasons, throws are normally taught in order of difficulty for both tori and uke. This is exemplified in the Gokyo (五教?, literally "five teachings"), a traditional grouping of throws arranged in order of difficulty of ukemi. Those grouped in Dai ikkyo (第一教?, literally "first teaching") are relatively simple to breakfall from whereas those grouped in dai gokyo (第五教?, literally "fifth teaching") are difficult to breakfall from.
A practitioner of judo is known as a Judoka (柔道家 jūdōka?, judo practitioner), though traditionally only those of 4th dan or higher were called "Judoka". The suffix -ka (家?), when added to a noun, means a person with expertise or special knowledge on that subject. Other practitioners below the rank of 4th dan used to be called kenkyu-sei (研究生?, trainees). The modern meaning of "Judoka" in English refers to a judo practitioner of any level of expertise.
A judo teacher is called sensei (先生?). The word sensei comes from sen or saki (before) and sei (life) – i.e. one who has preceded you. In Western dojo, it is common to call any instructor of dan grade sensei. Traditionally, that title was reserved for instructors of 4th dan and above.
Judo practitioners traditionally wear white uniforms called keikogi (稽古着, keikogi) practice clothing or judogi (柔道着 jūdōgi?, judo clothing). sometimes abbreviated in the west as "gi". It comprises a heavy cotton kimono-like jacket called an uwagi (上衣?, jacket), similar to traditional hanten (半纏?, workers jackets) fastened by an obi (帯 obi?, belt), coloured to indicate rank, and cotton draw-string zubon (ズボン?, trousers). Early examples of keikogi had short sleeves and trouser legs and the modern long-sleeved judogi was adopted in 1906.
The modern use of the blue judogi for high level competition was first suggested by Anton Geesink at the 1986 Maastricht IJF DC Meeting. For competition, a blue judogi is worn by one of the two competitors for ease of distinction by judges, referees, and spectators. In Japan, both judoka use a white judogi and the traditional red obi (based on the colors of the Japanese flag) is affixed to the belt of one competitor. Outside Japan, a colored obi may also be used for convenience in minor competitions, the blue judogi only being mandatory at the regional or higher levels, depending on organization. Japanese practitioners and traditionalists tend to look down on the use of blue because of the fact that judo is considered a pure sport, and replacing the pure white judogi for the impure blue, is an offense.
For events organized under the auspices of the International judo Federation (IJF), judogi have to bear the IJF Official Logo Mark Label. This label demonstrates that the judogi has passed a number of quality control tests to ensure it conforms to construction regulations ensuring it is not too stiff, flexible, rigid or slippery to allow the opponent to grip or to perform techniques.
Main article: List of judo organizations
The international governing body for judo is the International Judo Federation (IJF), founded in 1951. Members of the IJF include the African Judo Union (AJU), the Pan-American Judo Confederation (PJC), the Judo Union of Asia (JUA), the European Judo Union (EJU) and the Oceania Judo Union (OJU), each comprising a number of national judo associations. The IJF is responsible for organising international competition and hosts the World Judo Championships and is involved in running the Olympic Judo events.
Rank and grading
Judo is a hierarchical art, where seniority of judoka is designated by what is known as the kyu (級 kyū?) -dan (段 dan?) ranking system. This system was developed by Jigoro Kano based on the ranking system in the board game Go. Beginning students progress through kyu grades towards dan grades.
A judoka's position within the kyu-dan ranking system is displayed by the color of their belt. Beginning students typically wear a white belt, progressing through descending kyu ranks until they are deemed to have achieved a level of competence sufficient to be a dan grade, at which point they wear the kuro obi (黒帯?, black belt). The kyu-dan ranking system has since been widely adopted by modern martial arts.
The highest grade ever awarded jūdan (tenth degree black belt) has no formal requirements and is decided by the president of the Kodokan, currently Kano Jigoro's grandson Yukimitsu Kano. As of 2011, fifteen Japanese men have been promoted to this rank by the Kodokan, three of whom are still alive; the IJF and Western national federations have promoted another seven who are not recognized (at that level of rank) by the Kodokan. On July 28, 2011, the promotion board of USA Judo awarded Keiko Fukuda the rank of 10th dan, who is the first woman to be promoted to judo's highest level, albeit not a Kodokan-recognized rank.
Although dan ranks tend to be consistent between national organizations there is more variation in the kyū grades, with some countries having more kyū grades. Although initially kyū grade belt colours were uniformly white, today a variety of colours are used. The first black belts to denote a Dan rank in the 1880s, initially the wide obi was used; as practitioners trained in kimono, only white and black obi were used. It was not until the early 1900s, after the introduction of the judogi, that an expanded colored belt system of awarding rank was created.
- Judo by country
- Judo techniques, partial list of judo techniques
- List of celebrity judoka
- List of judoka
- Inman (2005) p. 10
- The first Olympic competition to award medals to women judoka was in 1992; in 1988, women competed as a demonstration sport. Inman (2005) p. 11
- Kano (2008) pp. 46–47
- Kano (2008) p. 1; Hoare (2009) p. 43
- Kano (2008) p. 2
- Hoare (2009) p. 44
- Fukuda (2004) p. 145
- Kano (2008) pp. 3–4; Hoare (2009) pp. 45–47; Fukuda (2004) pp. 145–152. Keiko Fukuda 9th Dan (born 1913) is the grand-daughter of Fukuda Hachinosuke, and is the last surviving direct student of Kano: Davis, Simon, "Be Strong, Be Gentle, Be Beautiful - Keiko Fukuda", United States Judo Federation, retrieved March 12, 2011
- Kano (2008) p. 6; Hoare (2009) p. 47
- Kano (2008) pp. 9–10
- Kano (2008) p. 11
- Kano (2005) p. 23
- Hoare (2009) pp. 52–53. For location of Eisho-ji temple, see:
"Way to Eisho-Ji Temple", Kodokan, retrieved March 14, 2011
- Kano (2008) p. 20
- Lowry (2006) p. 49
- Kano (2005) pp. 39–40
- For Kano's opinions on the wider applicability of jita kyōei to life see for example, Kano (2008) p. 107
- Hoare (2009) p. 56
- Judo had been used before then, as in the case of a Jujutsu school that called itself Chokushin-ryū Jūdō (直信流柔道?, Sometimes rendered as Jikishin-ryū Jūdō), but its use was rare.
- Daigo (2005) p. 8
- Numerous texts exist that describe the waza of judo in detail. Daigo (2005); Inokuma and Sato (1987); Kano (1994); Mifune (2004); and Ohlenkamp (2006) are some of the better examples
- Kano (1994) pp. 45–54
- Ishikawa and Draeger (1999) p. 179
- Kano (1994) pp. 42–43; Mifune (2004) pp. 41–43
- Kano (1994) p. 44; Mifune (2004) p. 44
- Takahashi (2005) pp. 39–43
- Daigo (2005) p. 10
- For full coverage of katame waza techniques extant in current judo competition rules see Adams (1991), Kashiwazaki (1992) and Kashiwazaki (1997)
- Koizumi, Gunji. "Ne-waza (Groundwork) and Atemi-waza (blows) in Judo". Judo. Budokwai Judo Quarterly Bulletin. Retrieved 11 September 2012.
- Adams (1991)
- Otaki & Draeger (1983) pp. 398–405; Kano (1982) pp. 192–203
- Daigo (2005) p. 9; Harrison (1952) pp. 162–168
- Ishikawa and Draeger (1999) p. 84
- Kano (1994) p. 142;Ishikawa and Draeger (1999) p. 84
- For a review of the ten official Kodokan kata, see Jones and Hanon (2010)
- Kano (1994) pp. 148–159; Otaki and Draeger, pp. 73–109, 139–266
- Kano (1994) pp. 160–172; Otaki and Draeger, pp. 110–138, 267–405
- Kano (1994) pp. 173–191
- Kano (1994) pp. 192–203
- Kano (1994) pp. 204–219; Fukuda (2004) pp. 1–144
- De Crée and Jones (2009a, 2009b, 2009c)
- Kano (1994) pp. 220–223
- De Crée (2012) pp. 56–94
- De Crée (2012) pp. 56–107
- Kano (1994) pp. 224–238
- Kano (1994) pp. 239–251
- De Crée and Jones (2011a, 2011b, 2011c)
- Fromm and Soames (1982) pp. 71–72, 109
- Mifune (2004) pp. 211–220
- Fromm and Soames (1982) pp. 71–72, 108–109
- Hoare (2005) pp. 4–7
- Hoare (2009) p. 109
- The Contribution of judo to Education by Kano Jigoro (judoinfo.com)
- Koizumi (1947)
- Black Belt Vol. 2, No. 2. Active Interest Media, Inc. Mar 1964. p. 27.
- Takahashi (2005) pp. 18–20
- Downey, G. (2007). "Producing pain: Techniques and technologies in no-Holds-barred fighting. Social Studies of Science, 37(2), 201-226.".
- Dure, B (June 12, 2008). "Do judo stars have MMA chops?". USA Today.
- Cheng, M. (July 10, 2012). "For some judo Olympians, MMA could be 2nd career". Associated Press Worldstream.
- Kashiwazaki (1997) pp. 14–15
- "The History of Sombo – European Judo is really Japanese Sambo?" by Brett Jacques and Scott Anderson   
- Kano, Jigoro. "The Contribution of Judo to Education". Retrieved 10 September 2012.
- Inokuma and Sato (1987) p. 253
- Inokuma and Sato (1987) p. 253; Lowry (2006) pp. 35–61
- Lowry (2006) p. 39
- Hoare (2005) p. 8
- "Introduction of the Blue Judogi". International Judo Federation.
- "Judogi Guidace", International Judo Federation, January 2011, retrieved March 11, 2011
- International Judo Federation, retrieved March 13, 2011
- Ohlenkamp, Neil (March 25, 2007). "The Judo Rank System". JudoInfo.com. Retrieved 2007-10-15.
- Adams, Neil (1991), Armlocks, Judo Masterclass Techniques, London: Ippon Books
- Cachia, Jeffrey (2009), Effective Judo, Sarasota, FL: Elite Publishing
- Daigo, Toshiro (2005), Kodokan Judo Throwing Techniques, Tokyo, Japan: Kodansha International
- De Crée, Carl (2012), The origin, inner essence, biomechanical fundamentals, and current teaching and performance anomalies of Kōdōkan jūdō’s esoteric sixth kata: The Itsutsu-no-kata ―"Forms of five", Rome, Italy: University of Rome
- De Crée, Carl; Jones, Llyr C. (2009a), "Kōdōkan Jūdō's Elusive Tenth Kata: The Gō-no-kata - "Forms of Proper Use of Force" - Part 1", Archives of Budo 5: 55–73
- De Crée, Carl; Jones, Llyr C. (2009b), "Kōdōkan Jūdō's Elusive Tenth Kata: The Gō-no-kata - "Forms of Proper Use of Force" - Part 2", Archives of Budo 5: 74–82
- De Crée, Carl; Jones, Llyr C. (2009c), "Kōdōkan Jūdō's Elusive Tenth Kata: The Gō-no-kata - "Forms of Proper Use of Force" - Part 3", Archives of Budo 5: 83–95
- De Crée, Carl; Jones, Llyr C. (2011a), "Kōdōkan Jūdō's Inauspicious Ninth Kata: The Joshi goshinhō - "Self-defense methods for females" - Part 1", Archives of Budo 7: 105–123
- De Crée, Carl; Jones, Llyr C. (2011b), "Kōdōkan Jūdō's Inauspicious Ninth Kata: The Joshi goshinhō - "Self-defense methods for females" - Part 2", Archives of Budo 7: 125–137
- De Crée, Carl; Jones, Llyr C. (2011c), "Kōdōkan Jūdō's Inauspicious Ninth Kata: The Joshi goshinhō - "Self-defense methods for females" - Part 3", Archives of Budo 7: 137–139
- Fromm, Alan; Soames, Nicolas (1982), Judo - The Gentle Way, London: Routledge & Kegan Paul Ltd
- Fukuda, Keiko (2004), Ju-No-Kata, Berkeley, California: North Atlantic Books
- Harrison, E.J. (1952), Manual of Judo, London: Foulsham
- Hoare, Syd (2005), "Development of judo competition rules", sydhoare.com, retrieved September 16, 2012
- Hoare, Syd (2009), A History of Judo, London: Yamagi Books
- Inman, Roy (2005), The Judo Handbook, UK: Silverdale Books
- Inokuma, Isao; Sato, Noboyuki (1987), Best Judo, Tokyo, Japan: Kodansha International
- Ishikawa, Takahiko; Draeger, Donn F. (1999), Judo Training Methods, Boston, Massachusetts: Tuttle Publishing
- Jones, Llyr C.; Hanon, Michael J. (2010), "The way of kata in Kodokan Judo", Journal of Asian Martial Arts 19: 8–37
- Kano, Jigoro (1994), Kodokan Judo, Tokyo, Japan: Kodansha
- Kano, Jigoro (2005), Naoki, Murata, ed., Mind Over Muscle: Writings from the founder of Judo, Tokyo, Japan: Kodansha
- Kano, Jigoro (2008), Watson, Brian N., ed., Judo Memoirs of Jigoro Kano, Victoria, BC: Trafford Publishing
- Kashiwazaki, Katsuhiko (1992), Shimewaza, Judo Masterclass Techniques, London: Ippon Books
- Kashiwazaki, Katsuhiko (1997), Osaekomi, Judo Masterclass Techniques, London: Ippon Books
- Koizumi, Gunji (April 1947), "1936 Conversation with Jigoro Kano", Budokwai Bulletin
- Lowry, Dave (2006), In the dojo. A guide to the rituals and etiquette of the Japanese martial arts, Boston, MA: Weatherhill
- Mifune, Kyuzo (2004), The Canon of Judo: Classic teachings on principles and techniques, Tokyo, Japan: Kodansha
- Ohlenkamp, Neil (2006), Judo Unleashed: Essential Throwing & Grappling Techniques for Intermediate to Advanced Martial Artists, Maidenhead: McGraw-Hill
- Otaki, Tadao; Draeger, Donn F. (1997), Judo Formal Techniques: Complete guide to Kodokan randori no kata (reprint ed.), Clarendon, Vermont: Tuttle Publishing
- Takahashi, Masao (2005), Mastering Judo, Champaign, Illinois: Human Kinetics
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- Judo at DMOZ
- International Judo Federation (IJF)—The worldwide governing body for judo
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Body composition and fat percentage of Thai judo athletes * 
Callister R. Physiological characteristics of elite judo athletes *