Aikido's Koshinage

Below is an excerpt from a long post at Ellis Amdur's KogenBudo blog. It examines the source and history of a signature Aikido technique, Koshinage. The common wisdom that it came from Daito Ryu may not be correct.

The full post may be read here.

There are two inter-related questions regarding the history of the development of aikido: 

• Does aikido owe anything to Yagyu Shingan-ryu, a classical martial tradition that Ueshiba Morihei studied before entering Daito-ryu? 
• How much did Ueshiba Morihei take from Daito-ryu in creating his art?

Part I: Ueshiba’s Koshinage

Is the koshinage of Ueshiba Morihei his creation, is it rooted in Daito-ryu,  or did he assimilate it from one of the other martial arts he previously studied?
Ueshiba’s koshinage is unique, at least in comparison to most ‘hip throws,’ as nage aligns his hips to the front of uke’s abdomen forming a ‘cross.’ (In Japanese this configuration is referred to using the Japanese kanji juji (十) for the number ten.)

The throw is effected by nage rotating his hips while shifting his weight from the leg closest to uke to the leg furthest away, combined with the use of gravity. The result is uke moves across nage’s loins and lower back, much like a seesaw on its fulcrum, with uke being thrown out and away from nage.
Saito Morihiro, who trained with Ueshiba longer than any other direct student, reinforces these points: “Step forward and position your right foot between your partner’s feet. Extend your left arm diagonally upward with feeling of pointing at the top corner of the wall and bring your partner’s stomach onto the small of your back in such a way that your two bodies form a cross.” (1) 
The overall effect of this technique is a hip throw that exploits the action of uke and gravity, resulting in little energy expenditure by nage, something Saito confirms,  reminiscing, “The founder once said jokingly that there were no better technique than koshinage and that he never got tired, even if he practiced it from morning to night.” (2)

Additionally, Saito explained that Ueshiba favored the koshinage of aikido over hip throws found in judo and other similar techniques, because koshinage as performed by Ueshiba affords nage the ability to move in any direction to address another attacker at any point of the technique.

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Identifying the Potential Source of Ueshiba’s Koshinage

During an interview, Ueshiba listed the martial arts he studied as, “Tenjin Shinyo-ryu from Tokusaburo Tozawa, then Kito-ryu, Yagyu-ryu, Aioi-ryu, and Shinkage-ryu, all of them jujutsu forms.” (5)  (NOTE: He describes his training in Daito-ryu elsewhere in this interview).

Ellis Amdur in Hidden in Plain Sight, Tracing the Roots of Ueshiba’s Power, clarifies Ueshiba’s statement regarding his jujutsu training. Based upon Amdur’s analysis of historical records, the progression of Ueshiba’s training  began with Tenjin Shinyo-ryu, which Amdur believes was followed by ‘old school’ judo that Ueshiba, like many, identified as Kito-ryu to differentiate the training from modern judo (which focuses on competition, something anathema to Ueshiba). Next, while in the Japanese military, Ueshiba studied Yagyu Shingan-ryu taijutsu. Amdur notes the reference by Ueshiba to Aioi-ryu appears to refer to a period of the development his own martial art, a transitional period between Daito-ryu and aikido, and Shinkage-ryu is probably a reference  to a menkyo given to Ueshiba by Takeda Sokaku for symbolic reasons. (6)
If Ueshiba’s koshinage is derived from one of the arts studied, then it would have to be found in one or more of the following jujutsu schools: Tenjin Shinyo-ryu, Kodokan judo, Yagyu Shingan-ryu taijutsu, or Daito-ryu.