Most of you already know this, but folders are great, and I'd like to submit data point #3,080.
Four weeks and 4 days ago, I underwent an OATS procedure for torn cartilage in my right knee. Two weeks ago, I started physical therapy, and today, I took my first "real" ride, aboard my Dahon Mariner D7.
Actually, I did ride it three days ago up and down the street, but I was still having some weird clicking and pain, but since then, every day has brought enough improvement that today I was able to ride for about 20 mins easily and without pain.
Although I'm still under doctor's orders to wear a brace that's locked fully extended when bearing my weight, I can unlock the brace and bend my leg when seated, and even put muscle power through the joint. The difficulty is that I still have some pain, and the brace does restrict movement somewhat even when unlocked, but this is where the Dahon comes in perfectly.
Thanks to it's low top tube, I can mount the bike with an easy step through rather than throwing my leg up and over; the low gearing allows me to spin with very light light leg pressure; the upright, stable riding position allows me to make sure I'm on my good leg when starting and dismounting easily.
So that's it; if you're recovering from knee surgery, there's no bike more accommodating of excellent recovery than a folder!
Ride safely, friends!