Posted by: Jack Mankin (MrBatspeed@aol.com) on Sun Sep 25 10:43:06 2005

>>> Quick Question Mr. Mankin, as your rotation process is in progress, are the wrists straight or is one pushing and the other pulling. Also just before contact is one pushing and the other pulling. <<<

Hi Karo

Like the hands, the wrists cannot push or pull on their own. The push/pull relationship of the hands and wrist is driven from the action of forearms, which in turn is driven by shoulder rotation and the larger muscles in the back and shoulders.

You may be referring to the acceleration of the bat-head from the cocking and un-cocking action of the wrist. – Batters who cock the bat-head forward (toward the pitcher) may use the un-cocking of the wrist to sweep the bat-head rearward to the launch position. But once the swing and shoulder rotation is fully initiated, the force exerted from the large muscles of the legs and torso overwhelms any contributes of the muscles that control wrist action.

Below is a post from the Archives regarding the role of the wrist in the swing.

Jack Mankin
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Re: Re: Re: Re: Re: Re: Re: Torque

Posted by: Jack Mankin (MrBatspeed@aol.com) on Mon Jan 7 00:56:01 2002

>>> Interesting conversation. Wrist snap, do you teach it? If I heard it once -----, A swing without wrist snap will be slow, with weak contact.

There's another way to visualize wrist snap and the hand path. That being, 'the legs crank the hand path', or the legs power the swing.

Adair's research is mainly in the scientific arena. He does talk about torque via the legs and hips. I cannot tell you the specifics on the swing, although it's basis involves a linear movement and the swing being a series of un-cocking actions. I like Adair's research on timing more than his mechanics (physics work).

It's to easy to jump to conclusions, we can start with a linear hand path and end with rotation. Weight shift without torso action, is futile IMNSHO, or without getting your butt into the swing.

Does Adair believe the swing is taken around the torso? Regardless of what I find rechecking Adair's physics project, when this 'cranking' (torque) takes place is important (or 'if') to the over-all swing. Shawn <<<

Hi Shawn

You have raised some interesting questions. I will give you my opinion on "wrist snap" in this thread. But I would like to combine your statement: " There's another way to visualize wrist snap and the hand path. That being, 'the legs crank the hand path', or the legs power the swing" with the subject of "separation" in a new thread.

In order to understand the role of the wrist in the swing, I think it is necessary to clarify what is powering the "wrist snap." Is the flexing and un-flexing action being powered by the muscle groups in the forearm or is the flexing and un-flexing caused more by the inertia and trajectories of the bat and the wrists serve mainly as hinges?

The muscle groups that control wrist action are a comparatively small group. Considering the bats' mass, it could only add a small percentage of the energy required to generate good bat speed. Also the baseball grip is constrictive to the range of wrist movement. Therefore, the value of what we commonly think of as “wrist snap” in the baseball/softball swing is way overblown. Although I’m sure the following statement will raise hackles on the necks of many of you, but.....before dashing off to the keyboard it may be wise to closely examine some video in frame-by-frame sequence. --- “During the swing, the more the wrists flex and un-flex - the weaker the swing.”

It probably would have been more accurate if I had stated - 'forced' to flex and un-flex. The wrist is forced to flex whenever the hands are extended forward without a corresponding angular displacement of the bat-head. This occurs when a batter extends the bat knob-first while allowing the bat-head to trail behind. -- Here is where the "linear kinetic energy transfer theory" misleads the batter. Thinking that once he has transferred his weight to a firm front leg and extended his hands, energy will be released that will un-cock the wrist and the bat will come flying through. ---(As I demonstrated in the instructional video), it doesn't happen. Only rotational energy transferred by a circular hand-path and torque applied to the bat can generate angular displacement of the bat. -- With a straighter hand-path the batter will need to rely more heavily on torque to bring the bat-head through.

With a more circular hand-path and applying torque earlier in the swing, a great hitter will keep his hands back longer and allow the arcing bat-head to keep better pace with the advancement of the hands. Much of the bat's early angular displacement takes place while the back-forearm is still in a more vertical position where the wrist can rotate instead of being forced to flex. So the wrist of a rotational hitter can stay much straighter during the swing.

With either the linear or rotational swing, what we perceive as “wrist snap” is actually the push-pull action of the arms applying torque to the bat as it approaches contact. --Example: Lead arm reaches full extension and acts as a pivot point for the back arm to push the bat around (torque). Note that during this action the wrist remained fairly straight. Basically the same is true when applying bottom-hand-torque but reversing the role of the hands and arms. In either case it is the push-pull action of the arm that generated angular displacement - not wrist snap.

Jack Mankin