Man, that was reactivity, thank you so much.
The plugin don't help that much for this problem or i didn't understand how. Do you had an idea about it. (but i will use it for other things I've planned later, anyway i'am very impressed by your community)
In fact it more a physic problem than a drawing problem. I had some problems to obtain a rigid and flexible curve.
Actually the segments are too bouncy or are too rigid and i didn't understood how link them properly.
It's my first contact with box2d physic but i keep trying. i'll post my .capx tomorrow if i had better result with the segment links that gonna be more easy to understand.
Anyway thank for your help ^^, if ever you(or some other members) got an idea i'll take it.
PS: I'm French so sometimes i do some mistakes in English. don't be afraid to report them (and don't be afraid by the mistakes themselves <img src="smileys/smiley17.gif" border="0" align="middle" />)