What it is- its overuse. Trying to push aside the real issue and blame it on something else. Its not throwing breaking balls. They may contribute, but really only in the overall pitch count. Last year on our hs team there were two kids who had elbow pain. Only one was a pitcher, other was a position player. Heres my point- neither one threw a breaking ball! Every arm is different, mechanics change from pitcher to pitcher. Some may be born with greater ligament strength. Some may condition better. Some may have bad luck. Not sure exactly how every case is but I do know that every kid has his threshold. For some it may be one inning while others it may be a complete game. But, its not hard to put two and two together to realize and understand that overusing an arm is not healthy and is definitely the fault in almost every case of throwing injury!
Sliders are not arm killers. Pitching too much- "ARM KILLERS"