My lower back feels like its got sand between the gaps of the back bone. Sometimes I can crack it with a nice twist, it'll go away. Its not one of those pains where people go GAH! and look like they got electrocuted. I've had that before, from various injuries, completely different. This just makes me feel like a creaky old man. But at 37, I guess old age comes on cats paws, a little thing here, a little thing there. To combat it, I'm doing some low-impact stretching without cracking the vertebra. It seems to help. I've been sitting to work for the last seventeen years, so I blame that.
If you sit at work and home, like most people, get a good chair. The best you can afford. Get one for work, too. If they won't pay for it, buy it yourself. People spend $2,000 on a bed, and $65 on a chair, and spend twice as much time in the chair. Does not compute.