Keen Injury and exercise

So, I fell down the stairs in my house a week ago, and as such have not really been able to exercise. I'm starting to get restless with no form of exercise. Anyone have any ideas of things I can do that won't require me to move my knee around a lot? I have bands, straps, and a few light weights around the house that I could use, just not real sure what there is i can do. I REALLY don't want to back slide and regain the ten pounds I've lost over these few months. Any tips?