Wow Jordy, this happened to me, a few years ago I was doing Yoga, and when I got up I couldn't turn my head too much, when I awoke the next morning, I was in agony. I went to the hospital, had xrays, the whole bit, they told me that I had a congenital birth defect in my neck, a seventh cervical rib that had detached and turned in, and in certain positions would cause it to flip forward and put pressure on a nerve. They sent me to a neuro clinic, who then told me I had curvature of the spine starting as well, and need months of therapy, and surgery to remove the rib, well, I am still here, sans surgery, have had it bother me once or twice, so I am with ya!