I don't think that pedaling backwards will help your stopping power any more than pedaling forwards.
If you divide up your pedal stroke into 4 arcs, you are pushing your foot in one of 4 directions (down, back, up, forward) throughout the revolution when biking normally. When you pedal backwards, you're pedaling in those same 4 directions, only in a different order (back, down, forward, up). It might work for developing some muscle memory for have a solid resistance all the way around the pedal stroke, but that's about the only benefit I can see from doing it.
*edit* Even then, when you are resisting the pedal stroke, the order of force is (up, forward, down, back). This is the same as the order for pedaling forwards, only 180 out of phase. I'm going to say that it won't help stopping at all.
Originally Posted by Dr Irwin Goldstein
Men should never ride bicycles. Riding should be banned and outlawed. It is
the most irrational form of exercise I could ever bring to discussion.
the strength you really need is resisting forward motion. pedaling backwards on the trainer would build momentum and carry you through the pedal stoke the same as going forward. it's worth a try though. let us know how it works.