Now I am in PT for the knee and the therapist has assigned me stationary biking 5-7 minutes each morning and night. He told me to wear athletic shoes with the best arch support and sole stability I could find and by trial and error to position my foot in the pedals so I don't irritate the plantar fascia or unnecessarily flex my foot. I've been doing it for a week now and so far, so good. My feet are no worse, and my knee is actually better. The bike I use at the therapy center has fairly long pedals and that seems to help support my whole foot too. I'd much rather be outside walking, but I think a good quality stationary bike may be part of my future.