Posted by: Jack Mankin (MrBatspeed@aol.com) on Fri Dec 28 17:50:53 2001

Hi All

The board will be ready to accept post in early January.

I have been reading some of the older threads and decided to bring “Developing Bat Speed??” back to the top. Using the shoulders during the swing has been made taboo by far to many coaches. Yet, a powerful shoulder rotation is vital and having a good understanding of how energy is developed in the lower body (and torso) and travels upward/and/outward to generate bat speed is essential to understanding the swing of a great hitter. I think this thread illustrates the problem many coaches have in this area.

Developing Bat Speed ??
Posted by: Jack Mankin (MrBatspeed@aol.com) on Tue Aug 8 23:51:48 2000


Question? --- Nothing that takes place below the armpits - not weight shift - not squashing the bug - not popping the hips - not the kinetic chain - not fast twitch muscles, etc., has any influence on developing bat speed -- Other Than Their Contribution To Shoulder Rotation. --- True or false?

Jack Mankin

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TRUE. Of course being long winded, I can't help but add it Might be more accurate to say "upper torso" instead of shoulder since this is what seems to be driving the handpath circle via proper arm positioning. Personally I find swing thoughts like swinging hard with the shoulders and maintaining the spine angle are helpful in both golf and hitting. It doesn't work for a lot of students though.

Tom Guerry

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Hi Tom

I agree, the "upper torso" would be more accurate, the lead arm can be across much of the chest during rotation. But the shoulders have been maligned by so many batting authorities that I thought I would spotlight them.

Added notes:
 The reason the "upper torso" muscles are contacting is -- to increase the rate of shoulder rotation
 “It doesn't work for a lot of students though.” Great shoulder rotation is of little value to a hitter with inefficient transfer mechanics.

Jack Mankin

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Jack.....i'm not a scientist but i have to strongly disagree with the statement....saying that rotation the hips, for example has value only to the extent that it contributes to shoulder rotation is , in my view bogus and not logical....what you seem to be saying is that as long as shoulder is at maximum rotation, lower body is irrelevant.....i could stand flat-footed with a bat in my hand and turn the shoulder as quickly as possible...i estimate that my "shoulder speed" would be about 90 % of my "shoulder speed" if i woild have inward turn, rotate hips, etc....but would i hit the ball 90 % as far?...of course not, more like 30 %.......it's like one of the fencedrillers said at hitting.com....he thinks that "handspeed" is what counts...but of course, standing flatfooted & no rotation i can "throw " my hands about as "fast" as i can with an inward turn, rotation, etc....so "handspeed" being roughly equal but obviously much less energy is transferred to bat using fence drill mechanics.......................................again, i'm not a scientist and i know i'm probably missing something here....i think what i'm missing has something to do with the efficiency of energy transfer to the bat........jack, i love your site & subscribe to many of your teachings, but i'm afraid you blew it on this one.......please don't kick me off your site......

respectfully, grc

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This statement is the essence of our beloved kinetic chain. Each link in the chain has to happen in its proper sequence. If the chain doesn't continue in sequence through the turning torso, then all that happened before is for naught.

Tom Guerry

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>>>Question? --- Nothing that takes place below the armpits - not weight shift - not squashing the bug - not popping the hips - not the kinetic chain - not fast twitch muscles, etc., has any influence on developing bat speed -- other than their contribution to shoulder rotation. True or false? <<<

False. True enough, bat speed will be generated from rotating the shoulders back and then forward, that is, 'cocking' the bat (hands) back before exploding forward. However, I have to believe that if my body, "from the armpits down" were somehow encased in concrete, I would generate significantly less bat speed.

Greg Norman

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I think the posts in this thread are missing Jack's point. The keywords are "other than their contribution to shoulder rotation." He isn't saying the lower half isn't contributing, quite the contrary.

"However, I have to believe that if my body, "from the armpits down" were somehow encased in concrete, I would generate significantly less bat speed."

Absolutely. Because the lower half could not influence shoulder rotation. This would be true regardless of what energy-transfer theory you subscribe to. I have to assume you really meant from the waist down, since encasing it at the armpits would also stop torso rotation.

Steve T

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grc et al-
This is the way (layperson's way) I conceptualize the kinetic chain, most of which is my interpretation of Paul Nyman's ideas. Please feel free to correct/comment on these concepts. As discussed at setpro regarding pitching (most recently in the one footed whip cracker thread), the kinetic chain delivers power by sequentially transferring momentum from the slower more massive parts of the body to the smaller (faster) mass parts. The ground up development of this power is somewhat similar in hitting and pitching to a point, but then the principles of how energy is transferred from the torso are quite different for these two skills. Jack's work is the first I know of that clarifies these principles of "transfer mechanics" and how they apply to hitting. As Jack points out, the bat is not a limber object like a whip or a towel or an arm, so the way you transfer energy from the torso is very different for a bat on the one hand and the ball on the other, even though both are ballistic motions.

I consider the ground up generation of power similar for both activities. The legs turn the hips. the torso is connected when the hips are at maximum angular velocity, then the hips are decelerated (stopped) sending their energy up into the rotating torso (creating the "up" or thrusting of the hips commonly seen just before contact). This is an action that has been termed "rotational whip” by some. The necessity of a short swing radius dictates that rotation should be around a stationary axis for hitting as opposed to a moving axis for pitching.
In the case of throwing, transfer of energy from the torso is primarily accomplished by whipping the arm/forearm/hand powered by the unloading of the scapulae which moves the shoulder socket in a nice arc.

In the case of hitting, Jack has demonstrated nicely that transfer is via creating a circular hand path and torque by positioning the arms so that the shoulder (torso turn) drives the hands in a circular path while the hands turn the bat about a point between them driven by the arms connection to the shoulders. Energy can not be efficiently whipped through the arms to the bat as is the case with throwing a ball. As the bat swings out, inertia of the system increases, so by conservation of momentum, the shoulder/torso turn slows, but this should not be mistaken (as it often has been) for the intentional slowing of the shoulders in an attempt to whip energy into the arms. The shoulders should be kept rotating while the bat is launched, then the bat overtakes the shoulders and pulls them around on the follow through. The circular hand path and torque need to be maintained until contact for best results.
In summary, both activities require a kinetic chain. In the case of throwing the kinetics are mainly whipping, in hitting, rotational whipping drives the torso, but then energy transfer is via torque and a circular handpath.

Tom Guerry

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Looking forward to our discussions,

Jack Mankin