I've been out of commission for the past year plus with a back injury. Finally found a physical therapist I've been seeing for the past month who is helping me build core muscles, and an overall workout to strengthen me from head to toe. It combine's strength training at the gym three times per week, with core training at the gym and at home. Here's the thing. I went for an MRI a few days ago to find out what's really up with my back, and it turns out that I have two bulging discs in my lower back that are putting pressure on my sciatic nerves. He's leaning towards surgery, but I've convinced him that I want to continue rehab to see if I can manage it (and I imagine it would help if I got myself back into shape before surgery anyway, as far as recovery goes). Does anyone here have any suggestions for a low impact exercise that I can add to the series of crunches and leg lifts that can be done at home? It has to be something that can be done in an apartment. Any suggestions I get will be bounced off my therapist, of course, but I'd still like some ideas. Thanks in advance.