I've suffered with backpain for almost a decade, a new foam mattress (Ikea) replacing a spring mattress seems to have helped a lot. It's a supportive foam with a memory foam top; firmer than the sprung mattress.

The only downside is, err, it doesn't bounce when you want to bounce, if y' catch my drift.

It feels quite different, definitely warmer (not a problem in UK), took a few days to get used to.