a few have been simple slips on ice or from not paying attention (and tripping)…
Personally, I don't even count that kind of thing as a running injury. It's a bad luck (or, in my case, bad coordination) injury.
could it be that what they mean by “overuse” is that as you tire your stride changes??
Even if this were the case, in most cases it wouldn't be overuse, it would still be improper use. Not taking the time to properly build up your fitness to the level needed to do what you need to do. It's not that you're overdoing things, it's that you're trying to do things the wrong way by building up too quickly.
I keep thinking about the people who's posts I read (on other sites) who talk about running marathons with 20-30 miles per week and then wonder while they are hurt during the marathon… gee, ya think doing your whole WEEK in about five hours might have something to do with it???
Ahh, yes. I don't think I need to state where I stand on that. This is a perfect example of what I'm talking about with improper use. A person who gets injured trying to do that is going to call it an overuse injury but is the overuse on the single day the cause of the problem or the undertraining, combined with the idea that “I can do in one single morning what I've trained myself to do over the span of 7 days” the cause?