As we see repeatedly with many of the empty-handed arts, a samurai required training in combat grappling should he either find himself weaponless against armed opponents or because he clashed with an enemy and was too close to cut effectively with his sword. Samurai naturally wore armor to battle and this restricted the use of many direct attacks on weak points of the body with the result that few strikes were practiced. With regard to armor, as the manufacture of protective covering improved, as it became stronger and lighter, it allowed greater flexibility. With this development the technique of Senjo Kumiuchi also evolved with combatants enjoying greater freedom of movement. The design and availability of armor in Asian countries is a vital factor in the development of the various arts and not only those in Japan. Not only was the plate armor of the European knights unavailable, it was in any case impractical to wear in the hot, humid climate of Asia (as the knights themselves discovered when crusading in the Holy Land).
Senjo Kumiuchi on the Battlefield
On the battlefield opponents would lock together, grasping each others forearms in order to control any weapon that may have been held. From this position they would struggle to sweep, throw, trip or otherwise unbalance the enemy. Once the enemy was forced to the ground a finishing technique would be employed and another opponent sought. This was, by necessity, a very harsh form of combat. The aim was not to subdue or merely injure, but to kill as quickly and efficiently as possible. The techniques of Senjo Kumiuchi were designed to ensure that the maximum amount of damage could be inflicted, including throws that drove the opponent directly into the ground, preventing him from executing a successful break fall. Compare this to modern day Judo where the throws, many of which have their origins in the battlefield, have been purposely altered to allow competitors to be able to break fall successfully thereby promoting Judo as a safe sport. That isn't to say that against an untrained opponent these throws wouldn't be effective, but it is worth highlighting and considering the differences. Traditionally, the first part of the enemy’s body to come into contact with the ground would have optimally been his head (attempting to break his neck outright). In modern Japanese martial arts, such as Judo and Aikido, the opponent’s body is flipped to a greater extent, allowing him to land across his shoulders or on his back, most of the impact absorbed by the forearm(s) slamming the mat fractionally before the body lands to lessen the impact.
Another successful technique was to dive atop a thrown opponent, forcing the air from the lungs of the unfortunate warrior pinned down to the ground and leaving him severely winded and no doubt with numerous broken ribs. Considering that the aggressor would himself have been wearing armor, thereby increasing his weight, this technique could prove highly effective. Finally, amid the muck and gore, the samurai would either attempt to break the neck of his adversary or draw a dagger that would be plunged into the body of his prone opponent.
To fight in such a manner required great strength and courage. Slipping and sliding, colliding and close enough to smell your opponent's fear and look into his eyes, the battlefield was not for the feint of heart. Such fearsome techniques and the harsh training that went along with their development came to be used less frequently in the years following Japan’s civil war period (that is, from the early seventeenth century on). The techniques of Senjo Kumiuchi changed and evolved and new styles emerged. These styles were collectively called Ju Jutsu.
