In the art of Aikido ukemi, the ability to initiate a movement with a partner and receive the technique which results, is half of the practice, as important as being able to execute the technique involved. But just as there are a number of stylistic interpretations on the technique side of the art, there are a number of ways in which these different styles teach ukemi.

Without discussing specific styles, the practice of technique (waza) can be divided into two methods. Static technique is designed to teach the practitioner how to draw power up through his structure from the earth and deliver it to his partner's center. It is a form of Aiki conditioning in which the uke (the one initiating the attack) and the nage (the one executing the technique) engage in a kind of mock battle in which the uke delivers an attack like a grab with all his might and the nage has to join his power to his partner's and execute a throw or lock without clashing with his partner's power. Nage purposely does not slip the attack or escape from it. He wants the attack to be strong for it is for his benefit that the attack is taking place. So he purposely allows the uke to optimize his strength and then he practices how to relax and blend with the uke's power, redirect it and execute the intended technique.

In static practice, it is appropriate for the uke to "resist" the technique which nage is attempting in so far as he does his grabbing attack with all his power. He doesn't try to change the technique or change his energy to counter uke's movement, he simply does the specified grab as strongly as he can and delivers strong, committed energy to his partner. If the partner's understanding of the technique is insufficient the uke may actually stop his technique. If this happens the nage should approach things thankfully as his partner has given him the gift of strong energy which, in the end will result in his developing stronger technique. Since each partner will take turns as uke and nage, it is important that this spiritual competition not be a matter of ego, one person trying to prevail over the other. This not a matter of winning and losing; each person sincerely delivers his best attack with the intention that it help his partner to be better. He hopes that when it is his turn to execute the technique that his partner will return the favor by giving his best attack. This all takes place with the recognition that since Aikido is an art in which most of the practice is done with a partner, it is only through the growth of the partners that one's growth can take place.

While static practice is usually done with full power, it is tempered to adjust to the level of the partner. A new beginner may use static practice using very low power in order to simply try to learn the movements of a new technique. It wouldn't be appropriate for a senior to grab so hard that he or she would be unable to do the technique (at least not over and over). The partner should adjust his attack to the point at which it is challenging for the partner at whatever his or her level of skill is. They should work to succeed but they must be allowed to succeed. The only thing one learns from having one's technique stopped over and over is that one's partner is more advanced than you are. This will not make one's technique better. When one sees someone attacking a junior in this manner it is not great power of technique one is witnessing, it is the power of a great ego.

Since static technique is about developing strength in one's technique it is appropriate for the uke to use the technique to make him stronger. Establishing a good center to center connection with the partner is important and one uses the technique to make one physically stronger. The uke will "receive the technique" taking as much of the tension of the technique into his own structure as possible. While this might involve physical pain it is a by product, not the ultimate goal of the technique. If the practice is done responsibly it should make the uke stronger and increasingly able to handle uke's power.

Static practice also has the benefit of allowing the nage to look at every detail of his technique. Because he allows the uke to attack strongly he will know instantly if there are any imperfections in his understanding of the technique. Every bit of tension he carries will become evident. Nage can feel any dead spots in his movement, places at which the uke starts to feel stronger. Because static technique is executed more slowly than flowing technique it is possible for the nage to analyze the effective and in effective aspects of his technique in detail, something that is not really possible or even desirable when it comes to flowing technique which is much more about learning intuitively, based on the "feel" of a host of subtle factors. For this reason, static technique is essential for beginners learning the kihon waza (basic techniques) of the art.

Flowing practice introduces several other factors into the uke / nage relationship. Spacing (ma-ai) and timing (de-ai) are not factors in static training but are crucial interrelated elements in flowing practice. Flowing practice can be done slowly, allowing the student to process what he is doing mentally while he is imprinting the motor skill or it can be done at full speed, in which case the goal is to attain the speed which a skilled attacker would have when he initiates an attack.

For the uke, spacing and timing are crucial elements. An attack launched too early (the same as too far away) will not reach the nage, or it will be easily defeated because of the unrealistic distance at which the attack is launched. An attack that is launched too late (the same as too close) has left the uke open to counter attack as he closed the distance to initiate his attack. It is imperative that uke and nage pay close attention to this aspect of the training because it is central to understanding all martial interactions. Without an understanding of spacing and timing there is no underlying reality to the movement being practiced. In this regard it is important that nage force the uke into attacking properly. If uke tries to get too close to nage before committing to his attack, nage should show him his opening (suki) by delivering a strike (atemi) to the uke rather than just wait for the attack. This happens especially often in sword work in which the uke will lift his sword for the attack as he starts moving forward. This is a fundamental error and nage should show him his suki by lifting his tip and allowing uke to run into it. If uke attempts to attack from an unrealistically far distance, nage should not move from his starting place thus showing the uke that his attack wouldn't have reached him. Often with sword, the nage will hold the bokken over his head horizontally to check if uke is really striking at the proper distance.

This is an aspect of ukemi which is far too often ignored or downplayed in many Aikido dojos. Many Aikido teachers focus intensively on the ability of the uke to move and fall and ignore his ability to deliver a strong, focused attack at a speed which could reasonably be expected to strike an opponent who wasn't cooperating. This results in a group of students who might be quite adept at executing techniques at the low level of speed an intensity at which their dojo mates initiate their attacks but who are incapable of maintaining the outward projection of their energy when attacked with what would constitute a real attack in another art.

Ukemi is 50% about being able to deliver that type of quality attack that will challenge the nage and force him to continually raise the level of his technique. It is impossible to reach the highest level of skill without having skilled ukes to train with. The uke should have a strong intention to either grab or strike the nage's center. There are some factors which are not well understood in this regard.

Commitment: The uke is fully committed to an attack but does not purposely over commit. He tries his best to deliver his strongest attack with speed and power without losing his sense of center, without overbalancing himself. In this regard his job is identical to that of nage. He strives to move but stay balanced at all times. If he is unbalanced he strives to correct that and regain his balance. There are some teachers of Aikido who encourage their students to deliver over-committed attacks. While this may make it easier to execute technique it is a detrimental training method as it only prepares the nage to deal with incompetent attacks and it separates the uke and nage roles into two distinct roles with different assumptions. This should not be the case. Ultimately the only difference between the uke and the nage should be who initiated the interaction. All attacks should be as balanced as possible (this is also crucial for delivering a forceful attack).

Tracking: Unless one is training at a slow pace for some reason, the uke should always have intention to strike the partner (or grab his center). If the nage moves, uke should track him if he can. It is essential that the uke NOT do what can be called "picture taking ukemi" in which he takes a mental picture of the target and attacks that target regardless of what the nage does after he initiates his attack. The "entry" in Aikido is largely about leading the Mind of the attacker, causing him to see what we want him to see and not see what we wish him to miss. This can not be done if there is no direct connection between the partners. Attacking a space which has been vacated destroys any alive connection between the partners and represents a "break" between them, something which Aikido practice strives to avoid at all costs. It is impossible to understand the nature of the entry unless the partner is trying his best to strike the center. Training him to not react to a movement which he is able to see and react to is fundamentally dishonest and produces an uke who is worthless as a training partner.

Intention: Aikido may be primarily a spiritual practice but is through the martial context of the training that we receive our feedback. If the training becomes martially dishonest it becomes impossible to know what one understands and what one doesn't. So it is incumbent on the uke to execute each element in his partner role to the best of his ability. A shomen uchi is a strike to the front of the head. It is uke's job when doing this attack to execute the strike and hit his partner in the head if he possibly can. It is the strength of this intention which allows the uke nage relationship to function in terms of aiki not just mechanics. This "intention" is an integral component of the aiki which makes Aikido the art it is.

The other 50% of ukemi is the ability to receive the technique which results from the interaction between the uke and the nage. This is also an area in which there is a range of interpretation. It is the role of uke that we can really experience the aspect of Aikido as a form of "moving meditation". Uke must be fully committed to his role as the attacker yet have the ability to let go of that attack in an instant when it is countered by nage's technique. If nage does his job properly there is no break between the instant at which the attack is countered and when the technique is executed. It is one smooth flow of movement. This is called katsu hayabi in Japanese which can be translated as "instant victory". It means that the nage has uke's center in the instant in which they come together. If nage is truly functioning at this level, uke must be responsive in the instant to every change of energy between himself and the nage.

This doesn't mean that the uke simply takes falls for nage. As we previously stated, the uke is attacking in as balanced a manner as possible and will attempt to correct any balance breaks if possible. But he is not attached to any particular position or alignment. His overriding concern is to maintain his sense of being "centered". Part of uke's training is to develop the knowledge that this "center" is moveable, independent of place or alignment. Uke maintains his sense of center even when he is flying through the air, even when he is upside down, rolling backwards or rolling forwards.

In the martial context ukemi is a function of defense. In older styles of jiu-jutsu in which emphasis on destroying the opponent was an essential part of the art, techniques were apt to be either destructive atemi or locks which were designed to destroy the limb which was locked. ukemi an essential skill in that it focused on escaping from the intended technique before it could be fully executed. Although some schools teach the student to really "receive the energy" of the technique before complying or falling, martially speaking this is a bit late for defensive ukemi. If we train this way in Aikido it is only because the techniques we are doing are designed to be done with little or no injury to the partner. One can take one's ukemi quite late and really feel the power of the technique in a way that would be impossible in a fighting situation. In combat if one "receives the technique" one has already lost. It is important to understand what the different approaches to ukemi are when one is training so that one can decide how to make proper choices for oneself based on what one's goals are.

Ukemi is quite a bit like surfing. As one perceives the energy of the technique one moves with it, never resisting. Just as in surfing, if one doesn't resist the energy one can have quite a bit of freedom to move within the larger movement of the wave (technique) but the instant one gets out of sync with the wave (technique) one is defeated by the overwhelming energy of the wave (technique). If one can ride just in front of the energy of the technique one can get to the point at which it is very difficult for an opponent to apply a lock or throw one harder than one wants to fall. The secret is to never try to stop the wave. The attacker needs to be able to abandon his attack in an instant and execute a fall that would unlock a joint or place him out of range for the atemi he wasn't in a position to counter. Sometimes ukemi would be to control the falls in such a way that no one could throw uke in a way that would injure him (i.e. on his head or shoulder). This does not mean however, that the uke cooperates with the nage, he rides the wave, which is different. A really good uke can move in such a way that he controls the nage without nage even being aware of it. By the time nage goes to throw he finds himself flying across the amt without even knowing how it happened.

If uke attacks in a balanced and committed fashion he doesn't take a fall unless the nage takes his center (kuzushi). Any attempt to execute a technique without kuzushi will result in a suki or opening and in that instant the role of uke and nage switch as uke takes advantage of that opening to execute a kaeshi waza, or reversal. Now uke becomes nage and nage is receiving the technique as uke. On the other hand uke doesn't resist the nage either. If uke resists nage's energy he is essentially putting himself out of sync with nage in a temporal sense. If nage is competent, the instant at which uke begins to resist a technique a new suki has been revealed and a new technique is being created to fill that suki.

Now we don't train this way all of the time. It is inappropriate to train this way when the students are still attempting to learn the basics of technique. As a learning tool we have the artificial designations of uke and nage. This allows us to create distinctions where none truly exist in order to make learning easier. This is a form of what the Buddhists call upaya or expedient means. It means that we make a distinction, which really does not exist, for the purpose of training. In a martial arts context there is no reality here. No one goes into a fight thinking he is uke Except at the beginning of one's Aikido training, one shouldn't think of the uke as being the one who falls down. This causes the uke to attack with the expectation of the attack not working and he anticipates taking the fall or complying with nage's technique. Anticipation is precisely what ukemi is NOT about. The entire Aikido interaction between the two partners is in the present, not the past (hanging on to an attack that isn't working), or in the future (taking a fall before the nage actually does the throw). This is what makes Aikido practice a form of meditation.

So when the uke attacks he is "just attacking". He has 100% intention to strike the partner. In the instant in which nage begins to respond to the attack, uke is already adjusting to the changes in timing and distance, and position created by nage's movement, he has let go of that attack which only existed as an idea in the past. Nage is doing the same thing; both are in the instant allowing the technique to create itself based on how the two come together. Nage doesn't anticipate by choosing a particular technique, rather he allows the appropriate technique to create itself based on how the two partners / opponents come together. If he misses his technique uke will have instantly executed one of his own because it was created for him by nage's mistake.

If one wishes to see where Aikido starts to become something of a mystical practice it is precisely here. If uke is adjusting constantly to nage's energy and nage is adjusting to uke's energy, who controls the interaction? This is the essential koan of Aikido. On some level training is all about solving this koan for oneself. But the essence of this koan is revealed precisely through a deep understanding of the martial application of the principles involved in the uke / nage relationship. Without that understanding Aikido movement is really only a dance which cannot reveal these secrets to anyone.