I am a youth baseball coach in Minnesota and am wondering what are the effects of youths (9-15) throwing pitches other than a fastball. What is the outcome to the arm/shoulder of a youth throwing a curve or changeup at such an early age?
Post by Glenn Fleisig, Ph.D. on May 17, 2005 14:24:15 GMT -6
The 1999 ASMI study on youth pitchers (Lyman et al, American Journal of Sports Medicine, 2002) looked at not only pitch counts but also pitch types. Here is a summary of that study.
This study was the first scientific proof that youth pitchers who throw breaking pitches (curveballs, sliders) have arm problems more often than youth pitchers who don't.
The theory for why breaking pitches are potentially dangerous for youth pitchers is that the growth plates (soft, growing spots) in the bones in the arm cannot handle high loads without breaking or chipping off.
Furthermore, biomechanical studies of adult pitchers at ASMI have shown that breaking pitches and fastballs have similar joint loads but different arm positions. Our suspicion is that for youth pitchers, loads might be higher in the curveball than fastball, because many of these pitchers might be using improper curveball mechanics. However no study has shown yet shown breaking pitch joint loads in youth pitchers.
ASMI and USA Baseball recommond that youth pitchers don't throw breaking pitches in competition until their growth plates have closed. This happens near the time of puberty as the child approches his full height. We have a saying that a boy shouldn't use curveballs until he's old enough to shave. ;D This sounds silly, but it make sense.
We suggest that they focus on learning good fastball mechanics and then add a change-up. With speed, location, and a change of speed, a youth pitcher can succeed and develop.
The full USA Baseball Guidelines can be found here.
This is an excellent article! I am a Physical Therapist in Oregon and actively involved in Junior Baseball of Oregon (JBO). Our present rules are dangerous at best.... ???We limit pitchers (ages 9-14) to 4 innings per game and 7 per week. Tounaments on weekends do not count... It is not unheard of for teams to play 45-65 games per season. I like the system of implimenting pitch counts per game and season. Does anyone know how this has worked out in Alabama? I would be interested in any information about programs that have implimented these measures and people/organizations to contact.
Post by Glenn Fleisig, Ph.D. on May 27, 2005 7:58:07 GMT -6
I get messages all the time. What I see is a growing trend and understanding about pitch counts instead of inning counts in youth baseball throughout the U.S. Pitch count rules seem to be coming into play at the local league level, rather than at the national organization level. (Little League is looking into the feasibility of pitch count rules.)
Post by Glenn Fleisig, Ph.D. on Jun 6, 2005 14:53:44 GMT -6
ASMI has not conducted any research on the knuckleball. That being said, our recommendations are that a knuckleball is a fine, safe choice to be used as an off-speed pitch. However, the youth pitcher must also work on his fastball as well. A youth pitcher who does not develop a fastball is most likley not going to develop the arm strength and arm speed to progress further.
I'm joining this discussion very late, but I'd like to point out that we also found that pitchers who used the change-up had a decreased risk of arm problems compared to pitchers who did not, so if you want to minimize injury risk while maximizing performance, it is likely best to have kids focus on the fastball and change-up and reserving the curveball until the elow and should have matured skeletally.
Can anyone from the ASMI staff comment on the slider for a high school level pitching staff? I have always been of the school of thought that it was a detrimental pitch from an 'elbow health' standpoint. Thanks.
Post by David Kingsley on Mar 29, 2006 17:31:54 GMT -6
ASMI recently published a study comparing forces and torques at the elbow, and shoulder for the fastball, curveball, change-up, and slider in college pitchers. We found that the change-up was probably the least harmful pitch because it (in general) produced the lowest forces and torques at the elbow and shoulder. When comparing the fastball, curveball, and slider, forces and torques were approximately the same for those three pitch types. The slider produced only one significantly higher value, which was shoulder horizontal adduction torque during the arm acceleration phase. Thus, the slider did not produce any higher forces or torques on the elbow.
Again, these were collegiate pitchers so there maybe some differences when looking at high school pitchers. ASMI will try to perform the same study with youth, high school, and professional pitchers in the future. Further, we use inverse dynamics to calculate joint loads. Although we found that the fastball, curveball, and slider forces and torques were approximately the same, the length, velocity, and force contribution of ligaments, tendons, and other structures maybe different between the pitch types because of our study design. For example, we cannot and it is very hard to accurately measure the actual load on the UCL. I hope that helps.
Glenn S. Fleisig, David S. Kingsley, Jeremy W. Loftice, Kenneth P. Dinnen, Rajiv Ranganathan, Shouchen Dun, Rafael F. Escamilla, and James R. Andrews. Kinetic Comparison Among the Fastball, Curveball, Change-up, and Slider in Collegiate Baseball Pitchers. American Journal of Sports Medicine, 34(3):423-430, 2006.