Sidearm Switch

Question
Hello, I've been playing baseball/softball for 12 years. In the last year I've noticed that my right arm has extensively been hurting or locking up after I throw anything. I am a sidearmer, always threw that way since I was little. Now I am trying to switch to overhead throwing. Which it is really difficult. However I do notice that when I try to throw overhead, my shoulder doesn't hurt. My question is what kind of drills or exercises or even techniques to change from sidearm to overhead?  

Answer
Hey Suzanne,

First of all, you need to find out why your arm hurts at all.  You could mess yourself up for the rest of the season.. It is only May, ya know.. Your arm should not hurt at all.  A week or two of rest could make you solid for the rest of the season. Consider this please.  I don't know of any drills for the switch, but I would not throw directly overhead.  Consider throwing three quarters instead.  This is the natural way of throwing a baseball. Less strain, etc... You will do the least damage if you throw this way..
Let me know how it goes and what you decided to do.. Please be careful and don't over do it.. If your arm gets worse without getting better, then STOP throwing and see a doctor.
Dennis