Here's the story of how it happened:
A few friends and I went to watch some MMA fights (which were amazing - there was a KO in under 30 seconds for one fight!), and after the fights, we thought it would be a good idea to try get into the cage and get some photos. (The friends I was with were all involved in some type of martial arts/boxing so this sounded like a great idea.) So we go down to cage level and start talking to some of the people who were involved in the fights. Miraculously my friend and I got into the cage and start play sparring.
We were probably in the cage for 45-60 seconds; maybe 90 seconds max. We went from play sparring to grappling on the ground. Eventually we were led out of the cage and the night went on.
The next day I sat in a sailing seminar for 8 hours - with very poor posture. I know - "practice what you preach". Sometimes you just can't get comfortable when you have to sit for long periods of time. I understand that too.
By Sunday afternoon I could barely move my neck in rotation or side bending (mainly to the left). I thought I could tough it out, but by bedtime my neck was throbbing and it was painful to even just lay down on my back.
Monday morning came, and I was able to get a massage, a chiropractic adjustment, and acupuncture - and then I had to work for 6 hours. By Tuesday morning I was 80% better. As the weeks have gone by, I am not 100%, but I'm almost there.
The Lesson of the story:
Don't trust your friend who you're play sparring with to not "make it real". Always be on your guard and make sure you ground through your centre of gravity.
Also - don't wait to get help. Because thinking that you can "tough it out" probably isn't the best idea.
Thank-you alternative medicine!