Usage of contact planes to model a special boundary condition

Hi,

for my linear elastic problem (3d, with a fixed button or top region and some forces on the other side) I want to define another special condition:

The condition is given by a direction as a normal vector of a 2d plane. Now I want to prevent node movement in that direction.

I saw in the examples that I cannot use the essential boundary conditions, because I am blocking an arbitrary direction and not a dimension (x, y, z). The idea is now to use a contact plane instead. Is that a good idea for defining this condition?

Thank you for your help.