There are 7 youth baseball leagues in Japan. A couple of them prohibit throwing breaking ball, except change-up, but the other don't. Recently, some teams in the leagues prohibiting it claim to cease the prohibition, because they are often beaten by the team belonging to the league without prohibition, in some inter-league games.
I would like to know whether or not there are any local rules prohibiting throwing breaking ball (curve, slider, and so on) in youth baseball, like a little league, in U.S.A. I also ask your opinion on throwing breaking balls in youth baseball.
Post by Glenn Fleisig, Ph.D. on Nov 1, 2007 7:13:10 GMT -6
I'm not sure what rules are or aren't in place.
I do know that the latest research points to amount of pitching as much more important that types of pitches for who gets hurt and who doesn't. Dr. Andrews and I talked about it at the 2007 Little League International Congress. Here is our presentation: www.littleleague.org/pitchcount/pitchpresentation.htm
We have a biomechanics study about youth curveballs coming out in an upcoming issue of The American Journal of Sports Medicine. Keep an eye out for that one.
Your new paper on comparison of pitch types for youth baseball pitchers looks like very similar to the results derived from college baseball pitchers, as I expected.
Combined with your kinetic results and epidemilogic results (Lyman, et al. 2002), Dr. Andrews and you concluded that risk from throwing a curveball is inconclusive. I agree.
But, I guess that one of reasons for the greater incidence of throwing injury for curveball is that the external load required to throw a curveball is less or similar to throwing a fastball, but the internal load may be different because of different configuration (directions of forearm and hand) and muscle activities.
Thank you for informing me your recent results and relating paper.
I would like to ask you one more question. The previous studies including above imply that we should not conclude that the curveball does contribute to the cause of elbow injuries. Why do ASMI and USA baseball recommend that learning curveball begin from 14 years old? It is much later than learning fastball and change-up.