I got a lower lumbar strain (essentially a tear) back in early June, and have not been able to do much since then. When it first happened (from too much biking/golfing), the doc also told me to a few weeks until I Can be active again, I'm finding out that was really 3-4 weeks before I could do normal things without excruciating pain (showering, sitting, standing, walking), but I have not regained full flexibility yet and still have some inflammation right now. It's looking like it will be another 3-4 weeks before I will be back at athletic functioning.

So I guess short of it is that back injuries, even if they seem mild, can take a long time to heal, so don't rush it, or you'll risk permanent chronic injury. For the first few weeks It was horribly painful to sit/stand transition, walk, drive, etc. (Mainly due to inflammation and tightness). Take lots of advil/anti inflammatories and do some stretching (as long as it doesn't hurt), other than that just go for walks and relax and wait for the injury to heal, which could be anywhere from 2-3 weeks to 2-3 months or longer.