In its 2012 Policy Statement on Baseball and Softball8, the AAP acknowledges the recent studies challenging the theory that the curveball and slider are stressful to the young elbow, but, on the basis of other studies showing increased injury among those who throw curve balls and sliders at early ages, continues to recommend that introduction of the curve ball be delayed until after age 14, or when
pubertal development has
advanced to the stage when the athlete has started to shave, and that sliders not be thrown until age 16.
We further hypothesized that youth more
advanced in
pubertal development would show increased neural response to peer rejection and acceptance (above and beyond the effects of age) in regions involved in social and affective processing.