ahh well i have been going to my chiropractor for a couple of weeks now for the same thing, it means you back is slightly out of alignment, and our muscles have been compensating for it until now, where the smallest thing will set it off (like walking set mine off) into a lot of pain cause the alignment might be pinching some nerves or something like that. so i say go to the chiropractor and he will alignment our back until it stop hurting.