I think one of those swing things that Tony sells is better... gazelle? But really the ultimate thing is to get something one will use.
I recently asked my PT if we could schedule me for the treadmill, just at level and very slow walking. I can't go out and walk around the block; if my back or hip goes out, I have no way to get home. Plus, I feel guilty (I know, I know) about not taking Caleb with me, and that's so much more energy and issues right now.
Well, the PT didn't say, "No." Not in one word. He looked at me and said, just movement is what you can do..just move slowly.

So it's beyond me to do that.
Do it while you can. I think the gazelle, or speed walking is the best, as it doesn't ruin your knees or jar your spine.