Hello, I'm a 25-year-old woman, and I had a back injury when I was 22 (I have no idea how or why I hurt my back, by the way - it just exploded with pain one day for no reason). Anyway, yesterday, after carrying a heavy footstool up a flight of stairs, my back started hurting - in the same spot as when I first injured it, the lumbar region - and then my left foot went numb all over the top and down to the big toe! It's still numb today, so I suppose it's been that way for over 24 hours now.
That's never happened before, not even when I've carried heavy things and made my back hurt from the old injury. So my question really is twofold: is there any condition that can make your back/spine weak (and therefore more prone to injury even when not engaging in all those indicators like lifting, sports, excessive bending etc); and is this foot numbness indicative of trapped-nerve problems in my back? Thanks in advance for any enlightenment you can bring to me!