Getting Uke's Foot Stuck
At North Shore Aikikai we've been looking at how to take uke's balance in a particular way. I've felt this particular off-balance in lots of techniques but in this class it was talked about and techniques picked to practice it.
There is a way to move uke in a circular motion that gets their foot stuck and they can't help but fall. How you get there may depend on what handles you grab(head, shoulder, arm, etc) but the motion is still the same. Draw uke slightly forward over his toes, then on to the side of his foot and maybe back again.
One of the important points is how you draw uke forward in this case. You don't want to simply pull uke forward or down. You want to draw uke up and forward a bit. This might be accomplished a number of ways but if you are using a hand on a shoulder for instance, you want to stroke the shoulder up and forward a tiny bit. That's enough to move them forward. Then you can start moving them so that they stick the edge of their feet.
One exercise had Matt simply grabbing the shoulder of my gi between two fingers and moving me in a circular motion. With no effort he was able to make me take a roll.
The one thing you have to be aware of is allowing uke to drop down. The second uke's hips go back or uke bends at the waist the possibility of sticking their foot becomes much harder. Why is this? When uke's body is stretched out you don't have the ability to compensate for motion. You can't involve your hips, knees, abdomen to soak up motion. This is why you want to move uke in an upward direction.
The same thing translates to a lot of techniques. I can absorb a lot of nikkyo by making micro adjustments in my posture. I do it subconsciously most of the time. Matt discovered if he did nikkyo from a little further away it locked my frame and I was unable to use my hips, knees, core, to suck up movement.
The effect is interesting. You don't feel off balance until it's too late. The hard part is being sensitive enough as nage to produce that effect in uke.