...I had one of those 4 wheeled walkers with a seat. I sat down and it started rolling and - just as the folks from physical therapy said would happen - you don't think to grab those brakes. I rolled off the side of the sidewalk and crashed. Well, I don't think I did anything but irritate the knee and the wife but it scared me. The walker is broken, I am a lot more gun shy about moving around and I am back on the pain killers temporarily.