Leg-locks were banned shortly after an 1899 exhibition match in Kyoto (held before Emperor Taishō) between Kodokan 3rd dan Yuji Hirooka and Fusen-ryū master Mataemon Tanabe. During the match Tanabe performed a throw and subsequently applied a leg-lock, breaking Hirooka's leg.
At the next meeting of the Butoku Kai that year, Kano proposed banning leg-locks from regular jujutsu/judo competitions due to:
- the possibility of injury to the legs
- concerns over the 'interestingness' of leglocks from a physical education perspective
Tanabe objected, noting that other aspects of judo were equally dangerous. However of those present only Kaisuke Masuda (Shinnuki-ryū) supported Tanabe, and thus the ban was decided by majority.
In spite of this, due to petition from Tanabe, one of his favourite leglocks ashi-garami was included in the Kodokan katame-no-kata.
Some years ago I came across an account of a match held in 1899/1900 which was attended by the Emperor. This account was either in the Kodokan’s monthly Judo magazine or it was in the Judo International which was a joint French-Japanese project. The match took the best part of thirty minutes and eventually the Kodokan man succumbed to an ashigarami leg lock. As I recall one of the competitors was Tanabe Mataemon. It was felt at the time that this was a messy match and should not have been held before the Emperor. Rule changes were mooted. I am still looking for that account.
• Tanabe Mataemon Talks About His Fusen-Ryu JuJitsu, translated from the Dai-Nippon Judo-Shi (Great Japan Judo History), 1939
Changes to match rules and the controversial Isogai match
In May, 1899, prior to the fifth Enbu Taikai of the Butoku Kai, an umpire conference was held, chaired by Jigoro Kano. I will pick it up from the memoirs of Mr. Sanzo Maruyama.
At the opening of the event, Chairman Kano said:
"During shiai 'ashi-hishigi' have the potential to damage the nerves of the legs, and I wish to abolish it because it is not very interesting in physical education."
Needless to say, Tanabe rebutted the argument, arguing that:
"Ashi-hishigi have never taken a human life, and there are some dangers in both the Shin-ryū (Kodokan style) and the Ko-ryū. Banning ashi-hishigi is a great blow for the Koryū."
However, when Kano asked the participants, "Those in favour of Tanabe's proposal," only Kaisuke Masuda
of Hiroshima (correction: Shinnuki-ryū) agreed. And since Hoshino Kumon, the head of the Shiten school in Kumamoto, represented Ko-ryū and agreed to the abolition, Tanabe had to concede.
Let us examine a little the ashi-hishigi used by Tanabe. Maruyama describes the injury in the previous bout as "knee joint". Since the historical ashi-hishigi refers to the current Achilles-heel-gatame, naturally, the point of pressure is the Achilles tendon, and it seems that Tanabe used tomoe-nage as an entry into ashi-hishigi (generally, the right foot of the opponent is placed on the right side, and the left foot is held on the left side, and it is sandwiched between both legs). Another entry was to pass the foot outside from the inside of both feet of the uke and to turn it outward, as such it may have been closer to "ashi-garami".
• 外編２−古流と講道館流 - Koryu and Kodokan style (archive: bokuden.or.jp)