Guillaume Erard wrote:
Since you can achieve these exercises, could you please explain to me how you physically perform them? Let's take the one with people pushing in front of you. Do you concentrate on "the one point" as Tohei says or is it all just a matter or redirecting the force? If the latter, we are therefore talking about a physical trick aren't we?
Think of it like this. Ever tried to lift someone who was unconcious? Hard isn't it? they seem really heavy. In order to lift someone you need to transfer force into their body, this is acheived by the use of your limbs as levers. If their body is tense, then the force you apply will be more easily transferred into them and as such they will be able to be lifted. If they are relaxed it becomes much harder (but not impossible).
Same thing when being pushed. You redirect the force in this instance (as you correctly mentioned) into your one point, and thus it travels through you into the floor. Pushing the floor over is obviously impossible, hence you do not move when pushed.
The important thing is to remain calm, relaxed and to stand up straight and keep a good posture. If your knees are locked then you are like a car without suspension so make sure they aren't, likewise your elbows. Your heels should be resting just above the floor and your weight should be on the balls of your feet. Imagine all the force being applied to you as going straight through you into your belly. If you're doing this correctly you will feel your feet being pressed into the floor when your partner(s) applies force to you.
The hardest part is not letting your mind drift. Keeping it in your one point is easy until someone touches you but when you feel that your mind tends to drift towards the part of your body they are touching.
Other than that there's not much I can tell you by writing it on the internet, best bet is to go to a ki soc dojo near you and ask the instructor.