The injection into my spine caused spread from the lumbar sympathetic block...the slicing of the nerves for my c-section to deliver my daughter, and the bump on my hip (which was really more of a kick...pretty hard when my boyfriend's nephew was rough housing with him). I've had other bumps and stuff that just caused severe pain...but no spread...of course...many of those have been in areas where I already have the CRPS so it's hard for something to spread to where it already is...lol. But I've had bumps on my right leg that haven't caused spread...I'm guessing it has more to do with the severity of the trauma...but then the bump on my hip was HARD but not particularly severe (not like slicing through nerves). So...I don't know...maybe it's just bizarre like so many other things about this condition...