Nothing can make you feel old vulnerable more quickly than a seemingly and out-of-the-blue bad back. And if you know the feeling, it's probably little comfort that four out of five adults will at some time share it. Yet, only a small percentage of back problems are truly serious. Eighty per cent of all lower-back pain is simple muscle strain. Even more important: Such pain almost always develops gradually - meaning the moment your back "goes out" is the end result, not the cause. And the cause, more often than not, is years and years of bad back habits. So, what can you do to buck the odds? That's what's coming up in the next few pages - a ten-minute, ten-move formula to prevent a back problem from ever developing. A little daily back attention at home, at work, in workouts can keep your back young for a long, long time. A healthy back stays that way from a supporting cast of strong and flexible muscles. That's why this simple routine zeroes in k...