Despite those facts, the technique is an exceptional example technique for training and illustrative purposes. It has proven to be ideal for demonstrating each of the 6 Tuite Principles (in the most readily and clearly recognized manner).
My own experience has shown that this technique is the most incorrectly performed tuite technique (that people assume that they're performing it correctly).
This technique is used as a response to a chest-level “push”. The tori's initial response should be to push-back (when the tori's hand intercepts the uke's pushing hand). This is taught to be done in a manner that when the tori's hand comes into contact with the uke's hand, it will occur palm to palm (finger's up, in a manner similar to when doing a “paddy-cake” type of action).
This initial piece of the practice motion/routine is alternated (Right/Left hand pushing/catching), until the student is comfortable with the involved motions (regardless of the side being pushed upon or by).
In the next stage of this learning/practice routine, we have the tori, begin stepping forward (with the stepping foot, angled slightly outward) this will be the same foot, as the tori's hand that is pushing-back.
Once the students are comfortable with these motions, we have the tori then modify the motion of the hand that is pushing-back (against the uke's hand). After making contact against the uke's pushing-hand, the tori will rotate their own hand (that is in contact with the uke's pushing-hand). The tori's thumb, should be pointed downward (and preferably, it isn't wrapped around the uke's fingers). It is preferable, that the student not “grab” the uke's fingers (using the their thumb in that manner).
Once the student's (and the instructors) are comfortable with their performance of these portions of the application, we begin having them include their other/free hand (that isn't doing the pushing-back yet). The student's will now have both hands raising (at the same time) to participate in the “catching” (of the uke's “push”).
When the tori raises the hand which does the “push-back/catch”), they will also raise their other hand. This hand will be placed against the radial-side (thumb-side), of the uke's wrist (of the “pushing” hand). The mistake made most often by the tori, is that they will grab the uke's wrist. This is to be avoided, as it will most often cause a failure of the technique, if/when done in such a manner.
Both of the tori's hands will move forward (in unison) as the uke's hand, is “pushed-back” (to the uke's shoulder) and is then Lowered to the uke's waist.
Tori's emphasis (with the “grab” portion) of the technique, should be on acquiring the “bind”, in the uke's wrist joint (as is found and utilized with the wrist manipulation exercise).
While the tori continues with the “push-back”, the tori's body-weight will commonly shift to their forward leg. The tori's hand/arm (that is performing the pushing-back) will then rotate (which will cause the uke's “pinky” finger to move towards the top of their own wrist). This rotation will pivot off of the fulcrum established by tori's secondary hand (which has been placed along the side of the uke's wrist).
The tori's arm (of the hand that is grasping the uke's finger's) will then rotate (further bending the uke's finger's rearward, at an angle across the uke's wrist). While this is being done, the tori will place their elbow against the uke's upper-arm (at a “mid-arm” location, between the elbow and the shoulder of the uke.
This “contact”, when done in practice is performed lightly (in use, it would equate to a strike, using the elbow). The tori's elbow/forearm is then slid down the uke's arm, to their mid-forearm, in conjunction with the tori rotating their forearm (as is done with an inside forearm strike/block).
*For practice purposes, we allow the tori to “bend” their wrist to limit the rotation of their own forearm (in order to control this motion, if this were not allowed to occur, the uke's finger's would be dislocated, and/or broken).
This resultant “wrist-rotation” will be combined with the tori rotating (their whole body) towards the technique. This allows the tori to utilize their body weight/body motion, in conjunction with the technique's application.
The action of the tori's forearm (motioning both inward and downward while in contact with the uke's arm) will prevent the uke, from either motioning that forearm “forward” (as if to strike the tori, in their “mid-section” with an upward elbow strike), or allow them to motion the elbow outward (to relieve the pressure that's being put on the wrist of the grabbed hand).
The reaction (that the tori is seeking to occur (on the part of the uke) is a sudden “knee-buckle”. It isn't actually necessary to continue the practice of the technique any further (at this level of training). If the technique had been performed at full-speed/power, the typical reaction (by the uke) would be their chest racing towards the floor.
For the purpose of “class-time” practice, we only seek to see a “knee-buckle”reaction to occur (by the uke). If/when that reaction is created, then (we know) that the tori had the ability to of initiated a full take-down (placing the uke upon the floor).
What should be noted by the student (when practicing this technique), is to note the uke's reaction to the technique's application. If the uke (only) bends forward (at the waist) when the tori applies the technique, they're performing it incorrectly. The primary reaction that we seek, is the uke's knee's to"buckle". They may bend forward afterword (or as well), but if the knee's don't buckle, they're not applying the technique correctly.
Once this technique has been taught to, and learned by the students, it is frequently used as a “reference” technique (for instruction of various principles and reactions). Many introductory (and advanced) motions and responses can be (easily) demonstrated, and exampled when using this technique as a reference (for the uke's responses).
I have seen this particular technique utilized in numerous demonstrations (and videos, on the web) by various systems and schools. To my knowledge, none of them practice it in the slow, controlled manner that we do, of the individuals that have come to our school (be it from within our system, or another), and have attempted it's application slowly, have (all) failed in the ability to elicit a proper response.
This is not to say that our method is better (though we do feel that it is, LOL), only that it is different. We believe it offers the best (learning) opportunity of practice (for students). As is shown with all of the technique's, the (simple) increasing of speed of application/execution, will make (even) a (totally) sloppy technique “work”(?) this is evidenced by the numerous examples that are displayed upon the internet.
Because of the created situation, (simply) creating some manner of a reaction is not that difficult. But, our goal is to educate the student, so that they understand the technique, as well as the how and why that it works, not just that they are able to create a response. The goal, is to create the desired response, otherwise it's just a cute "trick".