Aikido is usually described as an art made up of joint locks and throws so you should be wondering what the weapons are about. You’ll probably also be surprised to learn that weapons, especially the sword, are at the very heart of Aikido practice.

Despite the fact that Aikido is gendai budo, a modern art, the integration of weapon and body art is a very traditional one, there was simply little place for an unarmed art in a society like that of feudal Japan where “even lower-class people such as farmers, merchants and artisans all treasure a rusty short sword” and where civil war was endemic. There was, therefore, no distinction between armed and empty hand technique within many systems as a bushi was “never without swords at their side, even for a moment.” Only in moments of extreme desperation or rare occasions when an opponent needed to be taken alive would unarmed techniques be required and learning two sets of techniques would be impractical. The kata that were used to teach these techniques therefore taught both the use of weapons and the empty hand.

Although Aikido today concentrates on the empty hand, it is normal at Zanshin Kai for sensei to demonstrate kata with a weapon as in Aikido the weapon serves as guide to correct technique. In fact basic Aikido training revolves around wrist grabs, which simulate an attempt by an opponent to defend themselves against an attack with a weapon. Making the correct cuts to vulnerable points on uke’s body while maintaining the proper distance to use the sword effectively, that is so that the top inch or two of the sword does the cutting which prevents it becoming stuck in the body, ensures the technique is done correctly. So Aikido kata are as much weapon as empty-handed kata.
Use of the sword in particular in Aikido also ensures that correct body mechanics are used. At the start of Aikido training there is a tendency for new students to want to use their muscular strength to perform techniques; study of the sword encourages the use and development of the hips and also of good posture, which leads to more efficient and more powerful technique than is possible with the upper body.
Also in Aikido we have various weapons kata, some of which - particularly the Jo kata - can be done paired. This teaches the student to accurately judge distance, improves timing, builds confidence and also teaches the student to move. Performing the thirty-one count kata at full speed is possibly one of the most demanding training exercises in Aikido.
So as I’ve shown although Aikido is usually practiced as an empty handed art, it is impossible to separate the weapon art from the body art, the armed from the unarmed.

Alex Lawrence Nikyu no Zanshin Kai.