I'm going to breach an unspoken rule here and talk about one of the occupational hazards of being a musician, and that is pain associated with over-use syndrome. The reason musicians who suffer from this don't want to talk about it is that we don't really want word getting out that we hurt when we play. It could hurt our employment prospects. If treated carefully, it is very manageable, and it won't affect our ability to perform, but it can still be a difficult subject in a career in which the young and the restless (and the uninjured) are eager to compete.
Being a violinist, I'm most familiar with injuries associated with violin playing. In my mind, it's more common among violinists than other instrumentalists. We tend to be an uptight bunch. I used to have a theory explaining why violinists seemed most affected--and that was directly related to our close proximity to the conductor. I can speak from experience when I say that conductors seem to pick on first violinists more than any other group! It seems that the further back you are from the eyes of the conductor, the more laid-back the personality, hence, less tension. However, cellists seem (to me) more relaxed than violinists as a whole, and they're just as close to the conductor. Is it because they play lower notes? (Does a mellower instrument=a mellower player to go with it?) Or because they have big instruments behind which to hide that they don't seem as wound-up?
Truth is, it's not limited to violinists. I've spoken with horn players suffering from jaw problems, and pianists suffering from back problems, etc. I would like to discuss this issue in more detail with other musicians--find out tricks and techniques to prevent injury, and how to best heal when injured. If anyone has anything to share--helpful articles, books, or seminars addressing it, your personal experiences--I'd love to hear from you.