George S. Ledyard
Kevin, I completely fail to see the point of talking what could or could not be done on a machine."Aiki" in terms of technique is about two alive energy systems. Take "grounding" for instance. You can put a bear hug on someone and lift him up. If he knows how to ground out, he can shift his energy such that he will feel vastly heavier to the person lifting. If you had him on a scale, his weight wouldn't have changed but effectively, in terms of the interaction between the two people, his weight would feel as if it did.
The point of the machine was simply counter-example to the notion that unbendable arm is 'not a trick'. I think that it is a trick unless presented with disclaimers, as people are led to think that they are applying their whole weight to the bending, or an otherwise massive amount of force. In reality, they are essentially helping to keep the arm extended with their shoulder and limiting themselves when pulling on the elbow.
I had no problem with the exercise when it was presented to me, because my teacher said outright something like - this isn't as amazing a feat as it may seem, it's just an exercise to show you to extend your arm properly.
I don't really feel qualified to say how useful it ultimately is as an Aikido drill. I just thought the jargon being used to describe it sounded excessive.