Incorporar(se) vs. Levantar(se)

Question

I understand that "incorporarse" specifically means to "sit up" while "levantarse" has a much broader meaning.

My question is which of the two is more common or practical to use when telling somebody that is slouching, or laying down, to sit up properly'

Answer 1

{Personal pet peeve}
Please say "lying down," not "laying down," unless you mean that the person is setting an object down.

If a person is lying down in bed, for example, you could use incorporarse to mean "sit up," but if you made someone sit up straight (i.e., not slouch), it means that you "hiciste que se sentara (más) derecha."