The transition at 12U from 35 to 40 is a much bigger transition.
Well, it is a different kind of transition. The ball is bigger and the extra 5' does make a difference for the average kid moving from 10s to 12s. Most are still learning to pitch and if they are lucky, have command of two pitches, a fastball and a change. They are learning those pitches which require spin from a twisting wrist, like the screw, curve and rise.
The issue at 14s isn't about pitching speed and balls being hit back up the middle, its about biomechanics and the well being of the musculoskeletal system of a young teen.
At 43', there is more torque on the joints and growth plates in order to get the same break and movement that you get at 40'. The biggest factor here is that, with few exceptions, 13 yr old girls are still growing. That means growth plates (areas of growing tissue located at both ends of long bones that close and fill in with solid bone once the skeletal system stops growing) are susceptible to injury. This is EXACTLY why baseball limits pitches for boys and discourages a reliance on the curve ball. The difference is that girls generally stop growing before boys.
I don't necessarily accept your assertion that merely moving back 3 feet creates "trauma" or results in injury. If you have data showing that increasing distance alone creates injury, I would like to see it.
Sam hit on it with the example of the breaking ball. It takes more spin at a longer distance to get the same result. The rise is the best example. The more spin, coupled with speed, the later the break and more effective the pitch. Change those two factors and you have a rise thrown for a strike vs one out of the zone.
I agree that wear & tear and overuse injuries are a problem. But that is a frequency/mechanics issue not a distance issue.
Actually it's both. Pitching is the combination of biomechanics and physics. More spin means more wrist action, even with proper mechanics (which is an entirely different thread). There is a ball that measures spin, so its pretty easy to test the amount of spin and its impact on movement.
If ASA and Premier decide to move the distance back, they need to support that decision with medical evidence. The onus is on them to prove its safe in order to justify the change, not the other way around
Unfortunately most of what I read here from people in support of the change is why its better for the game, or more accurately, less inconvenience for a handful of people for 3 months during the 2nd year of 14U. This decision needs to be made based on what is in the overall best interests of the health of all the 13 and 14 year old girls that will be impacted. To do anything less than that is to prove what many believe - that winning is the bottom line.
This a sport where we have no guidelines for pitching safety, and an out of touch governing body that has repeatedly put profit and convenience over practical, sound decisions. Once this change has been made there will be no going back. Therefor it is crucial that there is objective deliberation with the benefit of the doubt be given to safety over convenience.
If anyone has any info on what people or committee will be making the recommendations on this deliberation, please post it here.