When to open up.

When should i open my shoulders. Just before my from foot plants or right when it does. Looking to get more velocity and will adjust a little if accuracy is terrible.

your shoulders should definitely still be closed at footplant, even well after foot plant. see these pictures.

throwinched is right. Rotate late. Hips finish rotating after foot plant. Shoulders rotate after hips.

And the more time you can have between maximum hip rotation and maximum shoulder rotation the better.

This is the most important concept in pitching, the most important factor in generating velocity.

I think that’s a very misleading way of putting it. It’s good to stretch far, but you need to do it quickly.

There is research that sugests the stretch-shortening cycle works best without inappropriate delays. So, technically, there is a proper timing. But most young pitchers don’t delay shoulder rotation enough so striving to delay shoulder rotation as long as possible might actually be an ok teach.

I’m not saying do it “slowly” or having a delay, I am talking more about having greater time between maximum, not start of, angular velocity of the hips and maximum, not start of, angular velocity of the shoulders.

From "Sequential Body Motion and Shoulder Joint Torque Between Baseball Pitchers of Various Levels, Arnel Aguinaldo, Children’s Hospital San Diego:

“Professional pitchers rotate their torsos much later in the pitch cycle (34+/-5%) compared to lower level pitchers.”

From "Kinematic and Kinetic Comparison of Baseball Pitching Among Various Levels of Development, Fleisig, Escamilla, etc, Journal of Biomechanics, Volume 32:

Average % pitch to maximum pelvis angular velocity:
Youth - 37%
Professional - 34%

Average % pitch to maximum upper torso angular velocity:
Youth - 49%
Professional - 52%

While the youth exhibits a 12% time difference between hips and shoulders, the professional pitcher exhibits an 18% time difference.

I think RBish has correctly interpreted Arnel’s recent paper. If anyone is interested in reading the complete research article, I can send along a .pdf file of it from my archives. (Anyone who is interested…I would need an e-mail address for you–I cannot post .pdf files here, nor can I attach them to PMs).

By the way, for those of you who may be unaware of it, Arnel Aguinaldo got his start in motion analysis for athletes by collaborating with Tom House and the NPA. He quickly adopted the NPA’s model for analyzing pitchers and has been working closely with House ever since. Back in 2003 my son actually got his first 3D high speed motion analysis from Arnel at the Children’s Hosp lab…that was pretty cool! The pitching mound was set up in the middle of a large hospital lab (complete with a couple of human skeletons dangling from poles) and he pitched to a catcher down the length of a hallway that adjoined the lab space. By that time, the docs who had offices along that particular hallway were well aware that they shouldn’t walk out of their offices without fair warning.

Shortly after 2003, House and the NPA installed a Vicon system of their own in the NPA’s facility; however, Arnel is still on the NPA advisory board.