Posted by: Jimmy () on Sun Jan 20 09:08:26 2008

> >>> Hi Jack,
>
> You state...""Therefore, in the “no-stride” approach, if there is no actual forward movement of mass, is there any forward momentum developed to power the swing?""
>
> I'm sorry Jack, but even in a "no stride" load there is a shifting or transfer of weight from one foot to another. Just because the front foot doesn't leave the ground doesn't mean that there is no weight shift.
>
> Any time that a mass is moving, that mass has momentum. A hitters body weight moving in a direction definitely produces momentum. <<<
>
> Hi Jimmy
>
> You state; “I'm sorry Jack, but even in a "no stride" load there is a shifting or transfer of weight from one foot to another.”
>
> Your reply points out the reason that I felt this subject needed further light shed on it. The video shows that during the swing, the responsibility for supporting Bonds’ weight did shift from his back foot to his front as you stated. However, during that time, his body rotated about a fixed axis, meaning his body mass attained zero forward velocity. -- Since p=mv, zero linear momentum was generated from what you describe as “weight shift.”
>
> Jack Mankin

Jack,

You are right when you notice the forward movement coming to a stop, but the force of the forward movement and momentum has transfered into the firm front leg. That feel of the force being applied into the front leg is one of the contributing forces that produces batspeed.

There is not one action or force that produces batspeed in a high level swing. It is a series of well timed actions and movements that produce many different forces including momentum. Yes the momentum stops at a point in the swing, but the force that the momentum provided is one of the contributing forces to the swing.

Your thoughts?

Jimmy