Posted by: dae () on Fri Sep 3 13:28:38 2010

> Hi All
>
> The Discussion Board has now been active for over 10 years. During that time we have debated about every aspect of swing mechanics. Since this site was the first to present a "Rotational Swing Model," almost every thread was dedicated to challenging the mechanical principles of that model.
>
> When the Board opened in 1999, even the most basic of those rotational principles, "Stationary Axis of Rotation" was strongly opposed. But that was mild compared to what was said regarding the Model's transfer mechanics that converted the body's rotational energy into bat speed -- a "Circular Hand Path (CHP)" & "Torque" (BHT - push/pull of the forearms).
>
> However, what brought forth the most vigorous (or vicious) opposition was THT (Top-Hand-Torque). Although the term was just a 'shorthand' way of referring to a mechanic used by the top hitters to accelerate the bat-head rearward, the very mention of the term seemed to stirred up a very negative reaction.
>
> I the earlier days of trying to explain THT, we did not have video clips of the swing available (like the one below) on site to show the bat-head's (or top-hand's) rearward trajectory. Added to that, most think of the swing as only a forward movement and have trouble visualizing the top-hand applying a rearward force.
>
> <a href="http://www.youtube.com/profile?user=MrBatSpeed#p/u/17/1YBuyUImIbw">PLT & THT Mechanics</a>
>
> After reviewing different Boards the past couple years, I noted that some of those that most vigorously opposed THT now teach its concepts to their students -- of course, giving it a different name for obvious reasons.
>
> Actually, my reason for writing this post was to address another mechanical concept I often found on those Boards. That concept basically states that the power for the swing comes from 'hip rotation' and the shoulders play little, or no, role in transferring that power to the bat.
>
> This site believes that concept is bio-mechanically impossible. The linkage to the bat (the arms) is connected at the shoulders -- not the hips. The main contribution of 'hip rotation' is to induce a stronger 'shoulder rotation'. --- I would like to hear anyone's thoughts that believe energy from 'hip rotation' can effect the bat's acceleration while the shoulders are held static.
>
> Jack Mankin


I haven't been on this board for awhile because my daughter is playing college ball and I don't coach anymore. But we used to show our players what moved the bathead and what didn't by first (1) getting into a stance, striding normally into an imaginary pitch, then violently turning the hips "into the ball" while keeping the front shoulder in place and the hands back. They could see for themselves that the bat-head didn't move. Then (2) we'd do the same thing, but along with violent turning of the hips, we'd slam the hands straight forward. Bat-head still didn't move (in any useful way). Finally we'd simply "coil and turn"........do the inward turn/shrug, then rotate the front shoulder into the ball. Here came the bat-head in unison with the hips.

Whatever the exact anotomical sequence, focusing on the front shoulder, coiling and "turning [the front shoulder] into the ball" worked well as a cue for our kids, 'unifying' shoulder and hip rotation.