I have Parkinsons for 19 years both knees and a hip replaced have rods installed in my lower back and need to exercise more. I am locaed in a lovely part of Michigan. Question is do you think I be able to enjoy a Trike? If so what should I be looking for when I purchase one, its tough for me to bend real low and have a slight balance problem. How may gears will are required for a fairly flat terain. Are the seats adjustable in height fore and aft and back angle. Anyone out there that has simialr issue that has riding experience that could advise me.