Tenkan (literally: “convert/divert”) is the simple yet devastating trick behind most aikidō techniques. Essentially a step-pivot, tenkan efficiently and gracefully converts the opponent’s linear motion into circular motion, disrupting their balance to drive takedowns, like kote-gaeshi and irimi-nage. Tenkan can also be used to quickly get behind an opponent, to set up kokyūhō, shihō-nage, the irimi pin, and other techniques. While tenkan is not a normal part of Goshin-Jutsu, the moves we have borrowed from aikidō work best within their original framework. To tenkan:
- Step out into a sanchin dachi, “pre-loading” your lead leg to prevent twisting it at the end. This can be a small step.
- Using your lead leg as a fixed pivot, rotate your rear leg behind you, and enter a front stance. The amount you should rotate is a point of contention within the aikidō community:
- Yoshinkan stylists believe that a tenkan should turn 95°; since that is the minimum rotation needed to produce the desired effect, so anything else is wasted motion.
- Aikikai stylists believe that a tenkan should turn 180°; since that is the maximum you can stably rotate, it optimizes the technique’s power.
[video of tenkan, back and forth, fast and slow, from the front and the side. ]