Brown,
Sorry to reply with a question -- but what kind of biking? When seated, one loads the spine. Active biking POUNDS the spine. Perhaps you are thinking about stationary biking?
Steve, I can't back this up with studies, but some people don't do well with the treadmill over the long term. For some percentage (small, I guess!?), it can lead to severe cramping and charlie horses. I am not sure why, but perhaps Rachel or others might be able to help us understand this from an exercise science perspective.
I'm no doc, but I say walk around your neighborhood (in safe conditions) and travel the variable terrain with good sneakers. The minor changes in grade are good for working all kinds of "small" muscles in your legs, trunk and back. I'll take walking/hiking any day over equipment. And you get fresh air, sunshine and nature -- there's no replacement for that!
Whatever the case, now is the time to take a break. You won't fall apart...and walking is an excellent choice of therapy AND exercise!!!
