Stan, this is so good and so well articulated I could not really hope to improve upon the content. Whilst it is pointed at Judo it is entirely relevant to Aikido, since all pushes in combat are in fact faster and therefore strikes.
“Preparatory moves are meant to disturb the CG and to move it outside the region of the base of support, thus making the opponent unstable. These moves are achieved by the application of what is technically called a torque on the opponent’s body. Torque itself is not a force but is a measure of the effectiveness of a force to produce some sort of rotation on the body, thus disturbing the CG and ultimately causing instability, or breaking of the balance.”
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