In the dojo, 90% of Aikido is uke
In our practice of the physical application of the techniques of Aikido, I have found that the skills of an uke are imperative to training. Learning Aikido and doing techniques is not just a individual activity, but demands cooperation between two people. The role of the uke is only to cooperate and move in a way that allows the nage to do a technique. It is not uke's place to teach, challenge, show openings, or overly resist nage's efforts. Nor should the uke simply move through a technique without any action of the nage. If the uke behaves in such a manner, then it hinders the nage's opportunity to learn and can confuse them or even lead them down the wrong path.
Here are some ways in which the uke should NOT behave:
1. The easy uke - Overreacts to atemi, and often jumps into ukemi. If the nage stops in the middle of a technique, the easy uke somehow keeps going through the technique and throws himself.
2. The stiff uke - Just stands there like a statue and waits for you to execute your technique. Stiff-arms nikyo applications and freezes their arm midair in a shomen uchi attack. Some say that this is a way of resisting and gives the nage a chance to test his technique and learn practical technique. However, this is not natural resistance, and is not even practical. Anyone who attacks another person, then stands there like a statue is going to either get poked in the eyeballs kneed in the groin or worse. The stiff uke usually doesn't react to atemi either, even when you stop white-knuckled at the tip of their nose.
3. The loose uke - This person also just stands there, but instead of being like a statue, they become completely relaxed. When you move their arm, their body and shoulder is disconnected making it extremely hard to do techniques like kaiten nage, or ikkyo. The loose uke expects you to be overly aggressive and TAKE their center. However, the problem with this is that now you are making the nage the attacker. Also, when doing techniques that simply shifts the uke's balance, the loose uke will simply move their feet to the place where they should fall, for example, just stepping to the "third leg" area. Again, the intention of the uke is good, to help you learn the technique in a practical way by not being an easy uke, but instead being difficult. A person who attacks and then relaxes and stands there gives no reason to do a technique.
4. The fighting uke - The biggest pain of all. This person always intentionally moves in the opposite direction that you intend to go, but the energy is there even before you move. So, you say OK, and decide to work with him and do some type of oyo henka move, and it works. The problem is that what you did wasn't what the sensei wanted you to practice,
3. The teacher uke - no matter how long this person has been practicing, his way is superior to yours. Often stops nage's techniques to make corrections. The intention is good, but the uke's limited understanding can hinder nage's learning.
The interesting thing is that we never see this type of behavior demonstrated on sensei. But then, perhaps this is why we sometimes hear stories of X Sensei breaking someone's arm.
The effect that this type of uke has on learning is negative. When a technique isn't working, we should think "What am I doing wrong?", but "Why is this happening this way?" This is extremely important especially for beginners to learn correct form and movement. Often times, someone is doing a technique correctly, but is given false information by a difficult uke.
In our practice of the physical application of the techniques of Aikido, the skills of an uke are imperative to training.