Hi, I have arthritis in both knees. I have not ridden pedal forward bikes. I have found that having the seat rather high helps a lot. Also, riding a lot has helped me. I ride mainly on flat land, no hills here, and I don't push my pain threshold. I ride once or twice a day. I have an exercise bike too. My Orthopedist says moving the joint helps. I also strengthen my legs by lifting weights. I do sets of twenty straight (unbent) leg lifts with ankle weights. I do them a couple times a week. I do them in three directions. This is supposed to strengthen the muscles around the knee and they act as a shock absorber.

I have had both knees scoped. I think if you have arthritis that it is bad operation. It was for me both times.