Posted by: George () on Thu Apr 5 18:58:50 2001

>>> My son,17, has been struggling with hitting line drives this year. At first I thought it was the heavier -3 bat required in HS. He's developed a good rotational swing but is hitting mostly hard grounders. Yesterday I asked him to use only shoulder rotation and arms and he was able to hit line drive after line drive. I'm aware that he lost power but I was amazed at how much bat head control he gained. When we included his hip rotation again I saw the problems return. What's hppening? timing? rolling wrists? over swinging? <<<
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> Hi George
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> Your son’s problem seems to exemplify the concern I have with batters using a light weight bat. The lighter bats allow the batter to attain good bat speed while using less efficient mechanics. Or in other words, they can use the smaller muscle groups in the hands and arms to accelerate the bat-head. -- Suppose you were to swing a 4 or 5 oz piece of plastic pipe. You could gain all the speed you would need just using the wrist of one hand and flipping it through. That would only use the back-side with a small amount of shoulder rotation.
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> The same is basically true with using a very light bat. Good speed can be gained by turning and extending the arms. The energy mainly comes from the back-side and the extending of the back arm. The lead-side and arm can sort of go along for the ride. But this type of mechanic just can not produce the energy needed to overcome the inertia offered by a heavier bat.
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> So, when your son swung the bat by just using shoulder rotation, he probably used the lead and back-side more evenly. But, when the hips were introduced, old muscle memories were brought back into play. With most mechanics taught today, popping the hips also means thrusting the back-arm forward with little thought of the lead-arm.
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> Jack Mankin
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>Thanks for your insights into this problem. A thought arose around hip rotation that might sound a little unusual. Imagine a string with a weight tied to its end or a sling with a rock in it. As the sling is twirled(rotated) and the rock accelerates the string end with the rock begins to rise up. As the speed of the rotation increases so does the centrifugal force which in turn causes the rock to lift upward almost at a 90 degree angel to the arm doing the twirling. Jack - can this also happen to the bat head when hip/shoulder rotation is maximized? What I'm getting at is, can my son's bat head speed be lifting it up a little by the time it contacts the ball thus impacting the top portion of the ball which is causing the hard grounders? Is this too strange to imagine? Again thanks for the help.