Here is what the news cast about tandem bikes/parkinsons patients was about.Part of the study test the effect's of exercise on parkinson's symptoms.[stationary bike].Best results occur when one can pedal 80 rpm's for a period of time.Most cannot.When a tandem bike is used,this is called forced exercise.The idea behind it is if we force them to pedal at a higher rate,this rate will allow them to have biochemical changes that are necessary for improvements in motor functions.There's also a possibilty that there's an increase in dopamine or there's a possibilty that there's an increase in neuro growth factors.The benefits only last as long as the patient sticks to the exercise regime.Currently my wife rides a stationary bike for an hour each morning at 40 rpm's.If anything,it would increase her heart rate[and mine] and would make her even more active.My wife can no longer go for long walks or ride her bike.What I am considering is buying a tandem bike and having someone convert into a stationary bike.I will keep everyone abreast of my findings.