Alternatives to lunges?

I had reconstructive surgery to my left foot and ankle last year and it's still been a problem. I've been doing a lot of different workouts like Jillian Michaels & some beach body ones but lungs are usually a constant exercise. What could I do instead of a lunge that would give similar results? They are just one thing that cause me a lot of pain and I can't really get a good range of motion because my ankle just can't move the way it should anymore. TIA!