My right shoulder.

The first summer I played baseball was the year I was 7, turning 8 in the fall, so that would make it 1985. The summer of 2015 is coming up; if I'd played every single summer of my life, that would mean I'd have already played 30 summers.

If memory serves, I had one year in high school where I didn't play, and I think two of the summers in which I was at Waterloo were baseball-free; just before teaching (2000) was another, my first year in grad school ('04), and that's about it. Every other summer I've played either softball or baseball -- plus essentially year-round the past two years.

My shoulder hurts when I throw now.

It started last summer; when I would play catch before a game, I just couldn't get loose. My first few throws, my shoulder would feel tight, as per normal, but usually when you get things going, that goes away. But there were a few times where, despite warming up for 5-10 minutes -- normally plenty of time to get warmed up and feel good -- it just wouldn't comply.

Nowadays, it's unusual if my shoulder feels good as a game starts, rather than the other way around. It's a pain and tightness in the front of the joint that won't go away. For normal, everyday activities, I'm fine, so it's no big deal most of the time.

But, I gotta wonder if 30-ish years of a lot of throwing aren't taking their toll. I've always prided myself on having a pretty good throwing arm, but maybe there are only so many bullets in this gun.