Was talking with an orthopedic surgeon recently about some knee issues my son is having (He plays at Furman) I noted that it sure seems like there are more knee injuries these days. He said there absolutely are and it was just a major topic at a conference he attended.
Some of reasons noted: -players are bigger, stronger, faster so just more torque when planting, changing directions, etc. -a lot of players just so focused on big muscle groups that often exercises that strengthen tendons, ligaments, etc not focused on enough, and players often bad about serious stretching
-Overuse. Football is now year round. Starting in HS, with the whole 7 and 7 summer season now, HS teams workout all summer. Their bodies are just not getting time to rest and heal.(from my sons experience I know this is true) It is a full time job. From the season, to spring practice, to mat drills, to summer workouts he says he never feels like his legs are ever "fresh". For us old timer if you recall we never had football practice until August after spring practice. HS League did not allow it. I think these "open seasons" allowed by HS League is a disservice to kids.
-one sport specialization taxes same body parts, over and over
-Playing surfaces. He says a lot of these new artificial turfs are a vast improvement over the old astro turf as far as not being like playing on cement, but they are "sticky" and if the wrong cleats are worn, the cleats literally work too well, leading to the over torque issue already mentioned.
I would be curious to know if Clemson tracks where the injuries are occurring. Are the more common on the indoor turf or grass practice fields?
The point about overuse with all the 7 on 7 and "camping" etc. is very valid. I've heard the exact same expressed by D1 coaches.
I would also say that kids (in general) start weight training in ernest earlier and then muscle strength gainsoutpace connective tissue strengthening and stretching which as the OP also points out is not emphasized. Most HS strength programs, run by well meaning coaches, only have a limited amount of time with kids and don't have time and/or don't know enough to emphasize anything but the main things... Adding strength and mass.