My 13 yr old had elbow issues. Went to Ortho Dr. Problem was growth plates in elbow. The way it was explained to me was the growth plates are likes thin sheets of paper. As the elbow matures, the "sheets" fuse together. My son's problem was the tendon/ligaments/muscles were stronger than the "sheets" and pulling the "sheets" apart. He could not pitch (or play catcher) for about 2-3 months. He played first and could hit. Never had another issue since then.