how to restraint

Hi all,

I have a simple question. I want to apply a force on a plasticchair. but i cant find a way to restrain its legs. because theselegs are not fixed. and also they are not hinged or anything.

if i am going to give them refference with geometry it did notwork.

i dont find any way how to restrain it so that when i apply a forceat the top of the table. it produces a real effect such as thetable legs stretced from their position to out ward position.

hope you can understand my question...........

please help me............SolidworksSimulation