When I was a teen, I broke my ankle in over twenty places and am missing some bones. There are times when it gets cranky and in that respect is like a sprained ankle.
If I have to keep weight off of it:
My first choice is swimming because of the great cardio work out. If my ankle is especially sore, then I'll use a buoy and lock my anles together.
If you can get your hands on a kayak, that's an awesome work out with no legs.
I'll use a bench and weights, working hard and long. I work on core by crossing my ankles off the bench, then doing flys, triceps and bench presses. I do it cardio style. Then I'll flip to my stomach and work my back muscles, trying to make it as cardio as possible.
Push ups, on the floor, on a ball, you name it, it's good.
Those are my top three. I have tons more if you tell me the things you like to do.
“Life is not a journey to the grave with intentions of arriving safely in a pretty well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out and loudly proclaiming ... WOW! What a ride!”