Well, she said (as well as the doc that did the venogram) that this was chronic and had developed over many years. First, I am a pretty small guy. I have learned to adapt and compensate upper body strength using less that perfect body mechanics especially when I was working as a FF/EMT. Second, I was a scuba instructor for 10 years. That's ten years of breathing through my mouth (using the accessory scalene muscles) and vigorously swimming all day every day. Couple that with a lot of computer use and poor posture. Then, I did some heavy yard work in which I pulled (bad idea) a very heavy trash can behind me. The next day, I pulled a patient up out of bed incorrectly and then after that went to the shooting range and beat the crap out of my shoulder shooting a rifle. 2 days after that is when the symptoms got bad. One doc initially diagnosed me with tendonitis in the scapula region and swelling of the bursa under the collar bone (coincidently right near the brachial plexus).