Hi, somebody know how use it without break arm? Or another part of our body...

I have the same and putting the bike on it is not easy.
Usually I lift the bike with a rear paddock stand, put that thing under the center stand and then let the bike down again. Not very practical but that`s the easiest way.

Used something much the same in the past (was a converted car creeper) easiest way I found was to roll bike up a car wheel ramp or similar structure (plank of wood on bricks) knock the center stand down, place under and roll back onto it.