Is Terry Laughlin Right?

Awhile ago, Terry asserted that there was an "epidemic" of shoulder injuries among young USS swimmers, which he asserted were all due to stroke defects. Is he right? Lately, I've been polling parents of 12-15 year old girls and I have learned that they all seem to have nagging injuries, particularly shoulder problems: Tendonitis, scapular pain, knee pain, etc. From what I know about the practice schedules, I don't think the injuries are due to overtraining, although some put in yardage or have some pretty hard practices. None of the girls I know do doubles. They all appear to be in puberty, and perhaps the changes in their bodies account for some of this pain. I'm sure some of it is due to bad technique too. I see a lot of lack of sufficient rotation on freestyle for example. But it's very annoying. Everyone is in PT or pain. I worry that some of these girls, including my own, will quit because they are tired of battling pain. Another thought. Elsewhere I read that one program started their girls on RC stuff beginning at age 10 and kids doing these exercises have had fewer shoulder problems. Should this be started at a young age? I know my kid is doing them. I have also heard of this problem mainly among girls. I don't know boys with shoulder problems. But that is likely due to the fact that I know more girls because I have a girl. Thoughts?