Arm angle question

I remember when i was growing up I always threw sidearm. But then when I was about 7 I switched to 3/4. But now when i throw 3/4 I get a tight pain in my shoulder. But then when i throw side armed I don’t feel it. If I stay 3/4 will i permanently damage my shoulder. Should I switch back to side armed to avoid injury or did I change early enough to avoid injury.

You do tilt your shoulders right? Your not like throwing 3/4 with your shoulders parallel with the ground right?

Do you ever get your elbow above the level of your shoulders using 3/4 arm slot? You may be improperly raising your arm slot from sidearm to 3/4.

Check out this picture of Clemens with 2 different arm slot/angle. Notice that his shoulder level are at different angles in relation to the ground.

Now look what happens when his shoulder level/tilt is the same. The arm is in the same exactly angle/slot.

If you take a photo of yourself at release no matter what arm slot/angle, your arm should be at the same position in relation to your shoulder level.