Doesn't sound as if the problem is bothering you that much. This is what I would be concerned with if I was a CAA examiner (which I am not!).
A word about the x-rays! Don't get too worried about these, they are usually pretty useless in predicting the natural history of back pain, ie you could be suffering severe pains, and have a normal looking x-ray, or you could be asymptomatAc with abnormal films ! Remember the definition of a well American ! One that hasn't had the tests yet ! (In other words, how you are actually feeling is more important than medical/physiological measurements) Good luck, keep swimming.
PS if you have any tips about landing a cessna172 I would be grateful!