Hi @aaw96
i am far from being an expert, plus new to this forum. i am just reading a lot here these days, as i am in midst a bad cycle at the moment.
but concerning your question:
it went down almost the same way for me! i basicly had a minor wakeboard accident over 10 years ago. result: nice whiplash. on the same day later at night i have felt this weird kind of pain (pain 7-8 CH scale) first time in my life... since then i do have experienced the same tension/blockade issues like you and for a long time i stayed pretty much undiagnosed because i was sure the CH pain was originating from the neck and shoulder blade area. And / or as well from nerve inflammation, or irritation. Which is possible. Maybe it was like that and it changed. Nobody can tell i guess. There is very little knowledge about all this, but based on what most people & doctors know, they will tell you CH are not caused by trauma. Some will tell you that they know so little, that you might be right, that you felt that kind of pain first time after the accident, but if you got CH symptoms and the CH meds/ treatments work for you, then you do have a CH (as well). So actually i support your theory of injury/ pain triggering it, or somehow being interconnected with it, but in the end it makes no difference.
