Ukemi is much more than tumbling. It is a whole set of skills of working in harmony with nage - no matter what they do. At higher levels it ceases to be a case of "nage does X technique therefore I do Y ukemi..." and instead a 'conversation' takes place and ukemi arises naturally. Developing a high level of ukemi actually makes us into better ukes - show me a great aikidoka and I'll bet they have a good understanding of the art of ukemi.
At Kotai level practice uke's job is simply to make a physical connection to nage through a wrist grab, to hang on for the ride and try to get their feet in place for the proper ukemi. However, as you progress to juntai level ukemi and beyond, you must be able to co-ordinate your mind and body through these movements to develop your aiki skills of following and protecting your body.
Fortunately our co-ordination exercises at the start of class (toitsu-taiso) and Aikido exercises (aiki-taiso) prepare us for this when done mindfully. We learn through these exercises how to co-ordinate the seika tanden (centre of gravity) of the body with the seichusen (centre line) with our eyes and most importantly with our minds through a variety of physical postures and movements. So how does this translate to receiving technique with ukemi?
Image Westbrook and Ratti, "Aikido and the Dynamic Sphere"
One of the very first techniques we learn in the dojo is katatekosadori kokyunage - the embryonic and high level stages of iriminage - it appears continually through the syllabus in the first striking technique (shomenuchi) and is something of a core technique of our art. The ukemi for it can be used for almost any technique in our syllabus, is less demanding physically than other ukemi and is a core method of self protection in many circumstances. So its a good choice in focusing on ukemi development.
Kotai - Static
At kotai level (static-level) we keep our centreline straight up and down sit down on our bum, knee first and go into a backward roll (not all the way over though). We grab cross handed and are brought in a circle around, down, up and finally down. The down part of this movement at the end is where we take the ushiro-ukemi (sit-down backward roll) and is often the toughest movement to translate to higher level practice, though this need not be so. (Why we grab and keep grabbing is the subject of a forthcoming post.)
Juntai - Flowing (nage leading, uke following)
At juntai or 'following-level' uke needs to respond to flowing energy and static level ukemi puts us in incorrect ma-ai (the wrong place at the wrong time) thus we are liable to be too slow and may end up running into nage's palm heel, their elbow or hip. There are three reason for this:
1) The body fights the incoming energy by resisting it rather than following it. This is fine if you are big and tough but is not going to help you develop or understand aiki
2/ The body responds to the incoming energy by launching up onto tippy toes to stop all forward motion, thus putting yourself in a posture where you cannot move easily
3/ Uke is still doing kotai level technique.
The remedy is simply when receiving juntai level technique (where nage is leading under movement) uke needs to follow completely with mind and body. Your eyes, your hand and tanden all need to follow this. Thus at the end of iris nage rather than standing tall, fighting nage or just stopping allow your eyes, your tanden and your hand to follow nage. If you focus on this the ukemi takes care of itself, the knees naturally buckle, the hips and tanden point up and you are halfway into your backward before you know it.
Ryutai and beyond
This preparation at juntai level is also preparing your body for ryutai (freestyle) movement, kutai (Universe or circle level) and finally kontai (Soul level). At kutai level nage movements consist of strong Ki extension with small movements that look almost like strikes, which only an adequately prepared uke can deal with effectively.
Some outtakes from the Aikido Yuishinkai Syllabus DVD.
(Watch the ukemi and look for co-ordination at work.)
adapted from (Ryutai - The elusive Freestyle Aikido practice )
The other half of the catalogue is as the second person in every kata - the uke. As uke you learn predefined responses to technique that are teaching you Aikido principles and preparing your body for higher level technique. In the ancient arts of Japan (Koryu arts) the role of uke was often performed by the teacher. Why? It is the hardest role to master. To provide the correct energy of the attack, to adjust your energy for nage's understanding and to receive from nage safely is as hard to master as the art itself. The great thing is that everything you learn as uke helps you as nage, at juntai level uke learns to follow nage.
This skill of sensitivity is what turns the potential for good Aikido into good Aikido.
Alas many never make the transition and forever muscle technique. Why? The challenge when moving from juntai to ryutai level is transcending 'making a technique work' and instead 'allowing it to work' through the energy provided by uke.
We learn the skill of allowing technique to work when practicing being uke at juntai level and learning to follow. Now as nage at ryutai we must provide some bait for uke and follow their attack. Drawing them closer we lead them, follow their response (repeat as necessary for long techniques) then apply focused ki at critical moments, following uke's reaction. Technique ceases to be something done to another person and becomes a 'conversation' where uke and nage swap and ride each others' energy.
Art of Ukemi >