[tannerj]

It's difficult for me to say. After I wrote the first comment, I remembered hearing long ago that the reason softball pitchers typically don't have arm trouble is that the under handed motion is a natural motion, while overhanded is very unnatural. With baseball you typically don't want to do anything that causes extra tension on the elbow (i.e. curve balls) at a young age. So, I only threw fastballs and change-ups until I was in middle school. You actually can cause a lot of ball movement with altering grip pressure. (but that's off topic.) I'd recommend talking to an orthopedic specialist if you have access. I had a bad case of tendonitis in my early teens and I remember seeing an otho doctor who had dealt with a lot of sports injuries. Also, reach out to a local college coach and ask. As always, be careful with advice off the internet, people are idiots. I know that from middle school on, we had very structured "bullpens" that would increase in pitch count as we got closer to the season starting up and that helped a lot. Unfortunately, it's been a long time and my memory is fuzzy. I also know that it's not one-to-one with softball. I found this pdf for Babe Ruth pitching rules[0]. If nothing else, I wouldn't exceed what they say.

[0]http://files.leagueathletics.com/Text/Documents/5200/27001.p...