This is a link to Day 6 Bicycles. They have several advantages for someone with MS or other health issues. First, a Day 6 Bicycle is an upright recumbent, meaning that you have a backrest. Second, you can put both feet on the ground while sitting on the bicycle. Third, you can add an electric motor, which drives the chain, not the wheel hub. That means you can maintain an aerobic workout by pedaling and using the electric motor to provide a little extra power going up hills. I have added the electric motor to my bike, which has made bicycling to work possible. I pedal hard so I get a good workout but I also use the motor to augment my pedaling so I can get to work in 25 minutes rather than an hour.