Jeff - I have experienced the same thing that you are describing - my ND was done in May '06 and last October I mentioned to my dr. that my neck was feeling tighter and "different". He attributed it to scar tissue, etc, and re-iterated the importance of keeping up my neck exercises, which I am pretty good about doing every day. It got worse, however, to the point I was having a burning pain sometimes in the side of my neck. I was sure something was going on. (I posted about this recently, if you look at my other posts) I should mention that I also have cervical spine arthritis, and have also had problems in the past with neck pain. Anyway, long story short, in January I saw all of my drs and had a CT scan since I was so worried, but everything is fine and they all say it's just a combination of the after effects of the ND and my other Neck issues....