Sometimes in aikido, you can get caught and there is no other place to go except under your attacker’s arm. Practicing turns will help you learn how to do this with the maximum possible efficiency.
This video shows how we do turns in our Tomiki aikido dojo. We don’t want to turn our back to the attack without having the greatest odds in our favor. However, there will be times when it is necessary. When you and the attacker are in the middle of a step, it is reasonably safe to turn your back to them. An attacker can’t put power on you if they are in the middle of a step without throwing themselves off balance. Learning to execute efficient turns can really help in these situations.