September 25, 2007 Softball News Service buzz²[ne.ws]® RSS
Here is the final installment of "Understanding The Science Behind Bat Speed". To help amateur softball athletes better understand the theory behind bat speed, Softball Institute asked Jack Mankin, head of Bat Speed, Inc., who has undertaken considerable research on the topic, to provide, in layman’s terms, a better understanding of the issue. This, his final installment, deals with the issue of "Wrist Action or Torque" - -Editor
Softball Bat Speed: Wrist Action or Torque
by Jack Mankin - Bat speed Inc.
Most coaches think the wrist play an important role in producing power and quickness for the softball/baseball swing. But the muscle groups that flex and un-flex (abduct and addult) the wrist are a comparably small muscle group and could have only a limited impact on the generation of bat speed. Therefore, I would like to offer a different observation I drew from my research of what appears to be the "snapping of the wrist."
For a ball to be hit over 400 feet, the bat head must be accelerated to a speed in excess of 70 MPH in less than 5/30 of a second. About half that speed is developed in the last 1/30 of a second. The large amount of inertia that must be overcome to accelerate the bat head 35 MPH or more in 1/30 of a second requires far more energy than the muscles in the hands, wrists and arms can produce. That kind of energy (about 3 torque HP) must come from the large muscle groups in the legs, back and shoulders.
The question then becomes; how is the energy transferred from the large muscle groups of the body up and on out to the bat head? I'm not going to cover the entire sequence at this time (omitting the initiation mechanics of the swing), but confine my remarks to the mechanics that appear to be wrist action or snapping of the wrist just prior to contact.
To explain the mechanics of how the large muscles are involved in this transfer, I am going to describe the swing mechanics of a Ken Griffey Jr., or hitters of his caliber, just prior to making contact. --- The large muscles in his legs and back have rotated his hips and shoulders to a point where the belly button and chest are now facing the pitcher. His lead shoulder is now starting to rotate back in the direction of the catcher. This means that the lead arm, and thus the bottom hand, are now being pulling back toward the catcher as the bat approaches contact. --- At the same time the rear shoulder (and top hand) are rotating around toward the pitcher.
This "pulling back" of the bottom hand as the top hand is being "driven forward", generates a tremendous amount of TORQUE on the bat. Torque is the result of forces being applied to the bat from opposing directions that causes an object (the bat) to rotate about a point between the two hands.
So, in the swing of a great hitter, what appears to be wrist action is actually the "push - pull" action of the hands generating a large amount of torque. This torque was developed from the large muscle groups and causes the bat head to be greatly accelerated. --- If the batter does not initiate the swing with torque and rotational forces, he will not be able to obtain the position of power required to apply maximum torque to the bat before contact. This is especially true for pitches on the outside part of the plate.
NOTE: Mechanics that would have both hands being thrust forward (both applying forces in relatively the same direction) produces much less torque. --- This type of mechanics just can not generate enough bat speed and power to produce a great hitter.
To upload the entire 4-part collection of Jack's research titled "Understanding the Science Behind Bat Speed" in pdf format log on to: >> Knowledge Center at Softball Institute.
_________________________________________________________________
Softball Institute.ORG is a softball education content provider focused on the finer points of the game of softball. SI publishes Library of Softball, Softball Broadcast Network, and publishes two demographic-specific blogs: National Forum of Girls' Fastpitch Softball and National Senior Softball Forum.
The Illusion of Power
Third in a Series About Bat Speed
The issue of bat speed has long been debated. To help amateur softball athletes better understand the theory behind bat speed, Softball Institute asked Jack Mankin, head of Bat Speed, Inc., who has undertaken considerable research on the topic, to provide, in layman’s terms, a better understanding of the issue. This, his third installment, deals with the issue of "The Illusion of Power" - -Editor
The Illusion of Power
By Jank Mankin - Bat Speed, Inc.
It didn't feel like I swung hard, but the ball seemed to explode off the bat." Most of us has experienced this sensation personally or heard others reflect on their experience. One might wonder, what was mechanically different in that swing and why can't it be repeated.
There is a strange paradox that occurs with the baseball swing. I refer to it as "The illusion of power." --- While warming up in the batter's box or hitting off of the tee, we can feel a sense power in the swing as we load-up and drive the top hand toward the ball. The harder we push on the bat through the contact zone the greater the pressure felt in the palm of the hand, and therefore the greater that sense of power.
The problem is, the "sense of power" we feel in the hands is actually the pressure felt from the resistance (inertia) of the bat to acceleration. The pressure felt is in reality an indicator of the lack of bat head acceleration. If the bat head had truly accelerated the pressure felt in the palm would have been alleviated or at least lessened. With linear mechanics, that sense of power means much of the bat speed is attained after the bat passes the contact zone.
However, if we were practicing our hitting and happened upon the mechanics that would really accelerate the bat (i.e., upper body rotational mechanics), the pressure felt in the palm as the bat passes through the zone would be much less and it wouldn't feel natural or as powerful. --- We would probably make changes to correct it in a hurry.
NOTE: Linear mechanics gives a batter the illusion of power. --- A great hitter experiences the centrifugal pull of a highly accelerated bat head.
Next Installment: Wrist Action or Torque
Softball Institute.ORG - Home of the Finer Points of the Game of Softball
If you're a hitter - baseball, slow pitch, or fastpitch softball, you'll definitely find this to your liking!
I'm a big proponent of appropriate strength & conditioning as a way of increasing GAME TIME performance. This includes generating maximal bat speed. Unfortunately, science says what most of you are doing in the on-deck circle just prior to stepping to the plate is hindering your bat speed and quickness right when you need it most.
What are most of you doing in the on-deck circle? Swinging some type of heavy implement. Why is this wrong? I've summarized below the results of a study done in 1991 by Dr. Coop Derenne of the University of Hawaii-Hilo. Results are ranked fastest to slowest by implement used. Bat velocity was measured by use of a photosensing computer timer. Players were college age; game bat weight was 30 oz:
1) Wooden overloaded bat (34 oz)
2) 27 oz underloaded bat
3) Standard 30 oz game bat
4) 25 oz underloaded batv 5) Power swing (adds 32 oz to bat)
6) 23 oz underloaded batv 7) Donut ring (adds 28 oz to bat)
Notice that the WORST item was the standard heavy batting donut. Also, using UNDERload (light) bats produced better readings than heavier implements. Just swinging your game bat with no weight attached produced better readings than any of the heavier tools!
The question you may be asking is WHY? Why, when you grab two or three bats or another heavy device, swing them vigorously, then grab your game bat (which now feels light as a feather) does this slow you down? You feel so much faster with your game bat after this, don't you?
What happens is simple fatigue of the fast twitch muscles you're depending on to perform at your best. At an imperceptible, neuromuscular level, all of this heavy work just before performing actually tires you out! So, right at the time you need to be your fastest, you've just slowed yourself down. It's sort of like a sprinter running a bunch of sprints or laps minutes before a race. Yes, he's warmed up, but he has also depleted too much of his energy, so he cannot perform at his peak.
Notice that the two best times were with weights that were about 10% above & 10% below the game bat weight. Just enough weight (the 34 oz bat) for you to get warmed up and ready, but light enough to not affect swing mechanics. The underload bat (27 oz) is noticeably lighter, allowing for an effective warm-up and priming the body to swing faster - overSPEED training.
Don't confuse this on-deck performance with a regular workout using heavy implements to develop strength and power. During such a workout, you're not appearing at the plate facing perhaps a 90 mph fastball. Tiring the muscles during a workout is the point.
However, this data underscores the fact that bat speed is most effectively developed by a combination of both heavy and light training. DO NOT NEGLECT OVERSPEED/UNDERLOAD TRAINING! If you only train slow and heavy, mechanics will be negatively affected (a real problem with a refined 'power skill' such as hitting) and you'll perform slow as well.
So put down that heavy device in the on-deck circle and go light! Especially when you're facing serious gas! And slow pitch hitters who are not facing 'gas,'you too need to generate maximal bat speed to drive the ball hard/deep.
Steve Zawrotny, MS, CSCS
405.373.3253
steve@baseballfit.com
FREE REPORT: "Harmful Resistance Exercises Baseball/Softball Players Should Avoid"
VISIT: http://www.BaseballFit.com
Article Source: http://EzineArticles.com/?expert=Steve_Zawrotny
Click on the screen to view video.
This video clip is brought to you by the Softball Broadcast Network. Log on to view dozens of videos from around the nation.
Editors Note: The issue of bat speed has long been debated. To help us better understand the theory behind bat speed, we’ve asked Jack Mankin, head of Bat Speed, Inc., who has undertaken considerable research on the topic, to give us in layman’s terms a better understanding of the issue.In the coming weeks, additional installments from Bat Speed will be posted. Your views on the subject are of course encouraged. --NSSF Editor.
Mechanics that Generate Bat SpeedMany tests have shown that rotational mechanics are far more efficient than linear mechanics in developing bat speed. In order to understand why this is true, it is important to understand the forces acting on the bat.
Other than the effects of gravity, drag (due to airflow) and other minor factors, there are two forces acting on the bat that create bat speed: Circular Hand Path (CHP) - The transfer of the body's rotational momentum that occurs when the hands are taken in a circular path.Torque - Torque is applied at the handle of the bat by the push/pull of the hands/arms/shoulders.Circular Hand Path The bat will undergo angular displacement (i.e., bat speed) when the path of the hands is also undergoing angular displacement (i.e., a circular hand path). In other words, as long as the path of the hands stays in a circular path as the body rotates, the circular hand path will transfer the body's rotational momentum into bat-head acceleration.
In technical terms, we often refer to bat-head acceleration generated from the CHP as the"Pendulum Effect" so as to distinguish it from the "Crack of the Whip" theory. (We'll take a brief digression to better explain this topic.) A pendulum is simply an object that swings freely back and forth in a circular arc (i.e., pendulum clock). However, in the baseball swing, there are two pendulums: 1) the lead-arm swings the hands in a circular arc, and 2) the end of the bat swings around the hands. This is referred to as the Double Pendulum Effect of a CHP.
A double pendulum consists of one pendulum attached to another. (To see an example of the Double Pendulum Effect of a CHP, Linear mechanics is much different in that it does not rely on a circular arc (or Pendulum Effect), as it is based on a theory that when the hands are extended in a straight line, the bat-head will suddenly accelerate to contact like the crack of a whip ("Whip Effect".) However, this theory is flawed since there is no whip effect in the baseball swing (a bat is not flexible like a whip), and consequently, efforts to produce a whip effect has stalled many hitters progress for decades.
A substantial portion of a good hitter's bat speed is derived from the circular path of his hands (think of swinging a ball on the end of a string). As long as we keep our hand in a circular path, the ball will continue to accelerate in a circle. However, if the path of the hand straightens, the ball on the end of the string loses angular velocity and trails behind the hands.
The same rational applies when a hitter is swinging a bat. If the hands are kept in a circular path, the bat will continue to accelerate. But if the hands straighten, the batter loses the circular path and the bat will lose speed. With a straighter hand path, the bat-head trails behind the hands well into the swing. This is often referred to as "knob of the bat first" and results in poor bat speed.
Torque is the result of two forces being applied to an object from opposing directions that cause the object to rotate about a point. Forces in the same direction may cause the object to accelerate, but will not cause the object to rotate about a point (no angular displacement). For example, when loosening a lug nut with a 4-prong tire wrench, you push down with one hand while pulling up with the other (torque). However, if you push down (or pull up) with both hands, you would not cause the nut to rotate (no torque).
Torque is applied in the swing by the push/pull action of the forearms and hands. The bat-head is accelerated from torque when the direction of force applied by the hands is from opposing directions.
To reach maximum bat speed, the batter must apply torque from initiation to contact and keep the hands in a circular path. Average hitters' usually have very little circular hand path in their swing (no pendulum effect) due to the straighter hand-path. As a result, average hitters rely mainly on torque to accelerate the bat-head. (Remember, there are only two forces acting on the bat - a circular hand path and torque. If one of the forces is missing, the batter will have to rely on the other force to move the bat.)
For a batter to attain his maximum potential, his mechanics must make efficient use of both - CHP and torque. Great hitters generate great bat speed because their swing mechanics efficiently apply torque at the handle that compliments the their circular hand path.
--Jack Mankin, Bat Speed, Inc.
Next installment: "Rotation and the Stationery Axis"
 |
|
