Hi there ... like the others, I had a knee replacement 15 years ago. For some unknown reason it never seemed quite "right" .... always hurt, poor range of motion, etc. My doctor sent me to more PT and after that didn't work, he did a Revision. That worked beautifully. I again did PT and after the PT they would put a TENS Machine on it, and I did everything I could at home to help it. It's now about 13 years later and my knee is as good as my left one. Maybe, like the other poster suggested .... start to walk, slowly at first, and then speeding up, or go to a gym and do a treadmill .... again slowly at first. Good luck. Barb