I used to have the nasty habit of cracking my neck if it ever felt tight, and around that time I started having chronic headaches. These go on all day - sometimes they go away for a minute or so, but then they're back.
I'm doing a paper on headaches and their causes. Does anyone know if cracking your neck can trigger headaches, and could anyone point me towards a source? I need to be able to quote a doctor or chiropractor for the paper I'm writing.

It would be great for my research and personal curiousity.

Thank you!