It's something that creeps up on you, but after awhile, you suddenly realize that your right shoulder, and just your right shoulder, is always sore. It's kind of a dull aching pain. Sometimes it even happens in the morning when you wake up.
I don't have the most poise in my posture. I slouch a lot. But as I'm getting older (mid-30's) I am paying more attention to aches and pains and posture. It's no fun to sleep it off when the pain starts up again first thing in the morning.
Fortunately, one of my friends has recently started massage training and she happily gives free massages. And in the last session, when I was asked if there was anything I wanted to concentrate on, I said my shoulder. Thinking about it, my right shoulder feels wobbly compared to my left shoulder. I can lift it up or down, but neither position feels very comfortable. Anyway, getting a full body massage is one of the finest things in life. I felt like a very tender piece of filet mignon. And it was after all this focused massage on my right shoulder that I finally figured out what it was.
It was the computer mouse. Because of crappy standard issue chairs and desks at work, I can't sit too high up without bumping my knees against the bottom of the desk. As a result I sit quite low compared to the keyboard. I can't just drop my arm onto the desk to manipulate the mouse. Now, instead of just raising my lower arm to give me freedom of using the mouse, I have learn to lift my entire arm starting at the right shoulder.
During most days, I spend a good part of my day raising my right shoulder to give me freedom of movement to use the mouse. That's why I didn't have a clear sense of an even position for my right shoulder, and my right shoulder gets a real workout. I've done it so often that lifting my right shoulder has become a habitual action – even while I'm sleeping.
Since that realization a week ago, I've been consciously forcing my right shoulder down, and only use the mouse with the lower arm. It's a strange sensation. However, I've eliminate most of the ache. Nevertheless, I am acutely aware of my right shoulder most of the time as I am constantly forcing it down into a more comfortable elevation. My body map of my right shoulder has it high up, so that it feels weird to have it low down – I must "force" it. But slowly I can feel my body map adjusting so that lifting my right shoulder up should feel like an odd and unusual motion.