Hi, Soccertese. Not sure how to interpret what you said in relation to what I said. What harm do you mean? I've had the joint problem for many years & have given various members of the medical community many opportunities to help me with it, with the end result being: no improvement, nada, zip. How do you know when you've found the best doctor? I've kind of given up on them & moved on. I see no harm in biking or other exercise as long as it doesn't aggravate or cause a problem. That's why I'm looking for a way to resolve the problem I seem to have with the recumbent bike. When using an upright bike, I don't seem to have the problem. Exercise seems to be the one thing that can help anyone, including those with PD, without the harmful side effects of meds or DBS, so why not?