I get so tired of reading posts that discuss aches and pains and surgery complications and all the meds being taken and "I can't this" or "I can't that"! This is a bicycle discussion forum.
If you're going to ride a bike, there will be soreness and aches and pains in the beginning but it will go away.
If you have "legitimate" back problems - that's allowable. But how many have back problems because of an oversized gut? Get rid of the gut and the back problems will probably go away.
Exercise and weight loss may reduce or eliminate prescribed meds so we can end that discussion.
How do you know you can't ride a road bike or a mountain bike. Bend over and try it.

Now let's get back to the bike discussions.