Importance of Acceleration Thru Impact

[saevel25]

Yes and these same people thought that pointing the clubface were you want the ball to end up and aiming your body were you want the ball to start was the correct way to hit a draw or a fade, which is wrong. Jack Nicholas was wrong, his method work because his body didn't do what his alignment did. He knew how to hit a fade because he spent countless hours hitting a fade. Telling other people how to do it, he doesn't have a clue what they need to feel to hit a fade. His method worked for him, but at impact the club is not were he aimed it, its in-between the target and his body line. If not, then he would hit every tree he ever tried to curve a ball around.

FEEL does not equate to what happens in the real world. Saying you accelerate doesn't mean you accelerate, and it can confuse people. Because they have no clue what accelerating through the ball means. Its like saying, ok i want you to pain this wall, to a person who has never painted before. When you come back you end up with a wall that is uneven and has tons of pain running down it.

Someone might feel like there getting there hands deep, or feel like they are maintaining there lag in the golf swing, when on video they might not. They might have to overexagerate by a lot to develop the correct motion and muscle memory

Butch is a damn good teacher, one of the best, what he does on a individual basis is amazing. But he knows as well as the best teachers is that each individual is different, and they have to search out there own feel to match the position they want. These general concepts of accelerating through the ball, which is physically incorrect as shown by scientific measurements, might only work for a select few to which is matches there feel in the golf swing.

Quote:

I understand the club head physically slows down at the moment of impact. What I and most instructors are saying is you do not quit accelerating at impact stay down on it and chase it all the way through to the target.

You just contradicted yourself. If the club head is SLOWING down, then the clubhead is DEACCELERATING. Acceleration is the rate at which you move over time. If you are gaining speed, your accelerating. If you hit the cruise control on your car, you are not accelerating. If you are slowing down you are DEACCELERATING.

No one is saying quit on a shot, but the notion that you are physically accelerating through the ball is FALSE, and MISLEADING.

All the year's i have watched amateurs, i have never seen them quit on a full shot. They might not make a proper shoulder rotation in the backswing, or might not have good hip rotation. But i have NEVER seen an Amateur quit in a swing with there hands or the clubhead on a full shot. Honestly, most Amateurs have a problem with thinking they need to accelerate so they end up casting the club at the ball, causing a massive power loss. Now for finesse shots, that is a different story, but you don't teach acceleration, if all other things are correct, there is no need to.

For example, when My dad chips the ball by taking a long backswing and deaccelerates way to early. This is not a problem with his acceleration, its a problem that he takes a way to long backswing and compensates for it. So the fix wouldn't be, ACCELERATE, the fix is elsewhere.

[saevel25]

Originally Posted by sacm3bill

Not taking a stance either way on the "accelerate through impact or not" issue, but for those of you saying that you should be getting maximum speed *at* impact and not before or after: How is that *not* a timing problem?

There is timing in golf, but if your getting in the proper position at impact it takes a lot of the timing out, especially if your on plane. You start coming from the inside to much, you really have to have that clubhead outside the hands going back or you will get stuck and have to flip the wrist over more to compensate. Or if you come over the top, you got to hold off on the natural rotation of the forearms to keep the face from shutting down and hooking the ball, or hitting a giant pull.

IF you have a neutral swing pat, 0 degrees towards +2 degrees, and you can deliver a flat left wrist at impact. Then you really shouldn't have problem with timing. Because having a slightly inside out swing path gives you leeway to hit a draw. If you have a zero swing path, you might not know were the heck its going to curve.

the issue is combining all these things at the same time, that's were good instruction and good practice methods help

[iacas]

Gloves off time. :)

Originally Posted by dereckbc

Sorry that does not intimidate me as I have a MSEE, with over 30 years of engineering experience with Professional Licensure so I know a thing or two about physics myself.

Unfortunately you're not demonstrating one bit of that in this discussion.

Originally Posted by dereckbc

As for your comments about instructors is quite condescending. One of the best instructors alive today knows a whole lot more than you or I do and strongly disagrees with you analogy. His name is Butch Harmon and I quote him.

Butch Harmon still thinks path is what determines the starting line of the ball. Sorry, but I don't really care what Butch Harmon has to say, and while I respect his abilities as a communicator, I do not respect his abilities when it comes to physics. The guy thinks the path determines where the ball starts. Case closed in terms of Butch's understanding of physics. Give me a break.

Originally Posted by dereckbc

What Butch is saying is what you hear many time when you watch a tournament from commentators like Johnny Miller when he says: He CHASED AFTER THE BALL. Meaning the player kept his body, hands, and arms accelerating through impact and through to the target.

It doesn't happen. Your body slows down WAY before impact. Your hands are decelerating at impact. It's really simple. The FEEL may not be that, but that's the REALITY of it.

I don't care what Butch says or Johnny Miller. Johnny Miller's understanding of basic physics is arguably worse than Butch Harmon's:

Originally Posted by dereckbc

I can find another dozen top name instructors if you wish like Flick, Ledbetter. Pelz (Pelz is a physicist) , all of which make a lot more money than us teaching PGA pros that will say basically the same thing.

In case it's not obvious already, I don't care what another instructor says. Turns out they're talking about FEELS only. Most instructors don't have advanced degrees in physics. You should look up the work of the ACTUAL scientists who are doing work within the realm of golf. Neal, Zick, Wood, Nesbit, Mackenzie, Tuxen, etc.

Originally Posted by dereckbc

I understand the club head physically slows down at the moment of impact. What I and most instructors are saying is you do not quit accelerating at impact stay down on it and chase it all the way through to the target.

And I'm saying, unequivocally, that it doesn't happen that way in the game's best players. Period. Bar none.

Originally Posted by dereckbc

Try telling Gary Player and Arnold Palmer they do not keep accelerating after impact. Their swings are famous for it because they went after it so hard after impact.

Wrong again. They felt like they did. They didn't.

Jim Furyk has said on many occasions that he doesn't feel any of the looping in his backswing for which he's famous. He's said many times he feels like it just goes straight back. It doesn't. Pros are historically unreliable - as is everyone - at being "real" with their "feel."

Originally Posted by dereckbc

When you do that you have your weight and momentum behind the club adding to its mass to drive through the ball.

Doesn't happen. The clubhead is acting as a free-flying object at impact. Nothing - zip, zero, zilch - of the forces in your hands, etc. are doing a darn thing to help "drive through the ball." The shaft could magically vanish the instant the club started to touch the golf ball and nothing about the flight of the ball would change.

Originally Posted by dereckbc

and no follow though to the target.

Your understanding of physics leaves a lot to be desired.

In no way does "not accelerating" mean "no follow through."

Originally Posted by dereckbc

That is the point I am trying to make you do not quit accelerating at impact. You drive through to the target.

No you don't. :) As I've proven - and as the actual scientists have proven - time and time again.

Originally Posted by saevel25

No one is saying quit on a shot, but the notion that you are physically accelerating through the ball is FALSE, and MISLEADING.

Don't mind dereck. He likes to put words in our mouths, like the "no follow through" drivel above.

Originally Posted by saevel25

the issue is combining all these things at the same time, that's were good instruction and good practice methods help

Yep. A good swing delivers the clubhead to the ball with the maximum speed.

Maximum speed after the ball - i.e. someone who "kept accelerating the clubhead through and after impact" - is wasted energy and thus a poorer swing than what's possible.

[phillyk]

Originally Posted by saevel25

I will concede one thing, you might be one of the very few people who need to think accelerate through impact. But i can tell you this, out of all my years, i have never thought that.

If you look at the kinetic chain graph, Rory's is a bit strange, because he actually has a weird hip ability, were his hips recoil, then fire again. That's why the red line goes negative, it has nothing to do with impact at all, but is very rare in sports the involve body rotation like golf.

The clubhead graph your seeing the clubhead speed oscilate due to impact, if there was no impact that would be a straight parabola, but hitting a 20 gram golf ball does transfer a ton of energy and does slow down the clubhead for a short time.

Then you see that the the other body parts re-speed up. This is not do to muscle want to expend more energy, this is due to the fact that the club is pulling your body into a finish. If you look at the peaks before impact, its Hips-Core-arms-Clubhead, in order of which they peak. But if you look in the order in which they speed up again, just after impact. Its arms-core-hips. This means the clubhead and its motion is so fast it is speeding up the body into a finish. This gives the illusion of accelerating through impact, when your BODY is not accelerating on its own accord, but being influence by a body of mass moving very fast. If you were to cut of the golf shaft at just bellow the grip. there would be no re-speed up of the body, because there would be no mass moving fast that passes the body.

Its physics, a body stays in motion until something effects it. Your body is slowing down at impact, the clubhead is speeding up to a max speed at impact.

for Rory, his hips have lost half there speed, His core lost about a 1/4 of its speed, and his arms have lost nearly half there speed at impact. They have deaccelerated greatly. It would be physically impossible, at that moment in the swing to tell your body, "ACCELERATE". That would mean in less than a 1/10 of a second before impact your telling your hands, core, and hips to increase speed. Its not happening. The only way they would increase speed is due to an outside force, that is momentum of a massive clubhead attached to a golf shaft that is dragging your hands, which drags your arms, which turns your core, and turns your hips. Basically the energy not spent hitting the golf ball is used and sent backwards into the body, giving that slight speed up.

cause if you were to keep accelerating, then the clubhead would have a constant increase in speed through that hole process, it doesn't its slowing down. Because energy travels from the ground up. If the clubhead is slowing down, there is no more energy acting as an accelerator for the clubhead.

1st) I NEVER said I try to think about accelerating through impact.  In fact as I had said before, I agree that physically, with the club head and ball, the club head slows after impact.

2nd) My post was talking about the biology of the muscles that affect the swing.  Albeit I left a ton of them out, but I only mentioned one to make a point. The point that your muscles throughout the swing are contracting and releasing.  In the very small amount of time of the physical component we have been talking about, there is very minimal biological change in the muscles.  The muscles as a whole may be moving slower, but the ones that were contracted before impact are most likely still contracted directly after impact.  Thus, they are still providing energy.  But, shortly thereafter the muscles release and others contract to slow the swing down in the follow through.  Only for a brief moment after impact are the muscles still exerting themselves to move the club head faster, even though it had slowed down.

[14ledo81]

Thanks Erik. I thought you had been a bit quiet these last few months. Threads like this (where you commented about how serious you were about the instruction that happens in your forum) are what got me following TST in the first place.

[kurisu]

Originally Posted by phillyk

1st) I NEVER said I try to think about accelerating through impact.  In fact as I had said before, I agree that physically, with the club head and ball, the club head slows after impact.

2nd) My post was talking about the biology of the muscles that affect the swing.  Albeit I left a ton of them out, but I only mentioned one to make a point. The point that your muscles throughout the swing are contracting and releasing.  In the very small amount of time of the physical component we have been talking about, there is very minimal biological change in the muscles.  The muscles as a whole may be moving slower, but the ones that were contracted before impact are most likely still contracted directly after impact.  Thus, they are still providing energy.  But, shortly thereafter the muscles release and others contract to slow the swing down in the follow through.  Only for a brief moment after impact are the muscles still exerting themselves to move the club head faster, even though it had slowed down.

Good god, stop talking, you're making a fool of yourself.

[phillyk]

Originally Posted by kurisu

Good god, stop talking, you're making a fool of yourself.

If you can read it,

http://bjsm.bmj.com/content/39/11/799.full.pdf+html (Muscle activity during the golf swing)

it's a summary paper of several experiments done to determine muscle activity during the swing.  According to the paper, the main muscles firing during the acceleration phase (on downswing, from club horizontal to impact) and the immediate follow through phase are the same, although the latter does see decreased activation.

It's also a cool paper to read if you care about the muscle activity throughout the swing.

[iacas]

Originally Posted by 14ledo81

Thanks Erik. I thought you had been a bit quiet these last few months. Threads like this (where you commented about how serious you were about the instruction that happens in your forum) are what got me following TST in the first place.

I appreciate that.

I've learned that I really can't get away from some people taking facts personally. I'm sure dereckbc thinks I'm attacking him. I'm a scientist, and facts are facts, and they're not personal. If I'm wrong, I don't care if someone tells me so. If they're right, and I'm wrong, and they can illustrate it, I'll have learned something and grown.

But I can't just let things that are known to be wrong slide. I take very seriously the fact that a lot of golfers have gotten better and learned a lot about the golf swing from visiting this site, and I try very hard NOT to let them learn things that I know to be incorrect, wrong, or misleading. I'm sure I fail more than I'd like, and maybe I'm not as clear as I believe I am all the time, but I appreciate that you said that. Thanks.

Originally Posted by phillyk

If you can read it,

http://bjsm.bmj.com/content/39/11/799.full.pdf+html (Muscle activity during the golf swing)

it's a summary paper of several experiments done to determine muscle activity during the swing.  According to the paper, the main muscles firing during the acceleration phase (on downswing, from club horizontal to impact) and the immediate follow through phase are the same, although the latter does see decreased activation.

In other words, the clubhead reaches maximum speed at impact and decelerates after that. Thanks. We knew that. :)

[Righty to Lefty]

I know that there are alot of people on here who are much smarter than me but I will still interject my opinion from my experience on the forum. It is hard to wrap your mind around something that you have been told is otherwise for a long time.  Just like I took my medicine from iacas about BFL's and he was correct all along. When I hear something new like this I have learned to immediately start trying to search for a reason for it to be true instead of disregarding it as false.  I say that because simply by saying that on a forum he knows that he just has to wait a few minutes and the storm will begin and if he is putting out bad information it won't take long before his site has lost credibility.

Now then I have a question and a scenario that I tried to come up with to explain this to myself:

What about a kid on a swing scenario:

1. If the kid isn't being pushed and is using his natural momentum, his top speed would be right before the lowpoint of the arch right, because after the lowpoint of the arch, deceleration would begin right?

2.  This wouldn't change even if you were being pushed by someone right?  Your arch would just get bigger right?  The acceleration and deceleration phases on each side of the lowpoint would still be the same no matter what right  ?

3. If someone tried to accelerate you PAST the lowpoint, they would not be able to ACCELERATE you, because during the DECELERATION phase they would feel you go from relatively weightless in feel, to very heavy as you moved past the low point?

I'm jus trying to come up with an explanation that us mere mortals can grasp and that was what I came up with!!  The low point equals contact and the person is the clubhead.  I'm I still far off in understanding this?

[logman]

Could I just chip in here with an observation. How does momentum work in the swing then? and does it relate to the rate of acceleration that you can exert on a club. The observation is you know how sometimes you see those guys that go to the gym too much out on the course hitting the ball. And most of the time they have incredible strength but no speed in their swings I liken then to diesel trucks that can carry any amount of weight but still only do 50 mph. on the other hand you see those skinny guys generate huge speed in their swings . are they the japanese motorcycles of the golf world. Yes I know it's a stupid analogy but I'm drunk so it's the best I can do. So what I'm saying is does the rate of acceleration make the swing feel like it's got momentum and decelerating might feel stronger in some swings more than others.

[ChrisGSZ]

I've only skip-read through this thread but what seems to be missing is what we should actually do (i.e. focus on mentally) during the downswing.

1. If we focus on accelerating body parts through impact, then we run the risk of destroying the intricate timing of the kinetic chain. Each body section has to slow down to pass energy on to the next link in the chain - so trying to accelerate something that needs to slow down can only disrupt things

2. If we focus on accelerating the clubhead , then we won't encounter this problem - our body parts are free to accelerate and slow down as they require.

It's worth remembering that the golf swing is a thing of physics, but it's controlled totally by our very un-physics-like brains. A simple mental focus on clubhead acceleration is likley to achie´ve better 'physics' than a mental focus on hips, arms, etc.....

[saevel25]

Quote:

Originally Posted by Righty to Lefty

I know that there are alot of people on here who are much smarter than me but I will still interject my opinion from my experience on the forum. It is hard to wrap your mind around something that you have been told is otherwise for a long time.  Just like I took my medicine from iacas about BFL's and he was correct all along. When I hear something new like this I have learned to immediately start trying to search for a reason for it to be true instead of disregarding it as false.  I say that because simply by saying that on a forum he knows that he just has to wait a few minutes and the storm will begin and if he is putting out bad information it won't take long before his site has lost credibility.

Now then I have a question and a scenario that I tried to come up with to explain this to myself:

What about a kid on a swing scenario:

1. If the kid isn't being pushed and is using his natural momentum, his top speed would be right before the lowpoint of the arch right, because after the lowpoint of the arch, deceleration would begin right?

2.  This wouldn't change even if you were being pushed by someone right?  Your arch would just get bigger right?  The acceleration and deceleration phases on each side of the lowpoint would still be the same no matter what right  ?

3. If someone tried to accelerate you PAST the lowpoint, they would not be able to ACCELERATE you, because during the DECELERATION phase they would feel you go from relatively weightless in feel, to very heavy as you moved past the low point?

I'm jus trying to come up with an explanation that us mere mortals can grasp and that was what I came up with!!  The low point equals contact and the person is the clubhead.  I'm I still far off in understanding this?

1) yes, maximum speed would be the low point

2) if you pulled the kid back and pushed him, the low point would still be the low point

3) Not necessarily, ever watch that episode on Mythbusters were there trying to swing past the top bar, making a 360. So they made a model and strapped some rockets to it. They were able to get the 360, they had an outside force as rockets.

If a kid was on his own, his speed would be govern by potential energy, mass x gravity x height, he would have maximum velocity and kenetic energy at the bottom of the swing, 1/2 x mass x velocity squared. golf swing is alot more complicated due biomechanics, but in the swing problem, that's the basic principle. That's why Rory has to have insane rotation speed compared to Dustin Johnson, he can rotate his body less because he's got half a foot height on Rory.

Dustin, 6.25 x 32.2 x 200 g = 40.25K

Rory, 5.75 x 32.2 x 200 g = 37.03K

Rory has to make up 8% loss in potential energy from height alone. If you look at the top 5 longest drivers, 3 of them are 6'3" or taller, and Rory is the only one under 6'. He's shorter by a lot, its not like he's 5'11". It just goes to show you how good he is at getting his top speed at impact. Before 2011 he wasn't near the top 5, now he's one of the longest hitters on tour.

Quote:

Could I just chip in here with an observation. How does momentum work in the swing then? and does it relate to the rate of acceleration that you can exert on a club. The observation is you know how sometimes you see those guys that go to the gym too much out on the course hitting the ball. And most of the time they have incredible strength but no speed in their swings I liken then to diesel trucks that can carry any amount of weight but still only do 50 mph. on the other hand you see those skinny guys generate huge speed in their swings . are they the japanese motorcycles of the golf world. Yes I know it's a stupid analogy but I'm drunk so it's the best I can do. So what I'm saying is does the rate of acceleration make the swing feel like it's got momentum and decelerating might feel stronger in some swings more than others.

Yes, when you derive the equations for momentum, Mass x velocity, you get rid of acceleration because you use calculus and integrals to derive the momentum equations. Basically you start off with the classic, Force = Mass x Acceleration. But after doing the integral, you get a change in force over time = impulse. Impulse equals change in momentum. Momentum is mass x velocity. So Acceleration is basically derived out.

Its not like a diesel truck, because the mass of the person swinging the club does matter.

No, acceleration has nothing to do with it. Basically how you feel the clubhead is totally based on the swing weight of the club, basically how much weight is towards one end of the club versus the other. Add a few strips of lead tape to the clubhead and you can make it feel like its a lot heavier during the swing than the amount of weight you put on.

Quote:

1. If we focus on accelerating body parts through impact, then we run the risk of destroying the intricate timing of the kinetic chain. Each body section has to slow down to pass energy on to the next link in the chain - so trying to accelerate something that needs to slow down can only disrupt things

YES, they do, if you look at the kinetic chain graph, each part that fires first (Hips, then torso, then arms, then club), each of them peak first and start loosing speed way before impact. Given Rory's acceleration is insanely fast in the downswing, Rory's hips fire at 650-700 degrees per second, over a 0.15 second area.  Your looking at and average of 4350 degrees per second square. That's absurd. But if you look at his hips from maximium rotation into impact, they deaccelerate at 6700 degrees per second squared on average. So he's accelerating greatly his hips, but they are deaccelerating greating because all that energy is then transfered to upward.

But lets say if you were to accelerate through impact, shifting the graph over, lets say you have your arms at max acceleration at impact, instead of the clubhead, your looking at a loss of nearly 14-15% the rotation speed of the clubhead. That would be a substantial loss of power.

[saevel25]

Here's the problem, if you go back to that first video posted about Pelz's instruction on Impact.

He says, you make a relatively short backswing and accelerate through the ball. Yet they show an video of professional, who takes a 3/4 swing for a green side bunker shot. If you took a 3/4 swing from a fairway you would hit the ball way farther than necessary than for a bunker shot. The reason a bunker shot goes shorter.

1) open clubface

2) your hitting behind the ball, and propelling the ball with  SAND. Majority of the energy is being transfered to the sand, and in retrospect the ball never touches the clubface. So instead of hitting down on the ball, hitting the ball first you are propelling the ball out of the bunker, with sand.

The reason the clubhead is moving past the ball, is that in the image bellow you have a few things different than a full swing. Look at impact on the golf swing, hands will be slightly infront of the ball, maybe at the ball at impact, clubhead will be just behind the hands, or at the hands at impact. Post impact, his hands stay very close to the body, not your typical extension. When you do this, the hands will break down, and the swing will take on a flipping action. What Amateurs tend to do before impact. The reason pro's are doing this is to get the club to slide through the sand, and it adds loft to the club, and keeps the club from digging into the sand. We've known for years, and even current professionals say, flipping at the ball is a power loss. So how is it suddenly an acceleration move in a bunker, yet before impact is a power loss move for a full swing?

The reason the clubhead is past the ball, 1) the ball is being carried by sand and doesn't make contact with the clubface. 2) this swing is is changed to were you do not have the same extension, so your lessening the distance the clubhead travels on its arc compared to a fulls wing.

[logman]

Hi saevel, thanks for some of the insights BUT....ha ha. You know the sorts of swings I'm trying to highlight. The heavily muscled guys that take half swings and seem to muscle the ball, surely their acceleration has to be greater because the guys using a half swing....as opposed to a long slow smooth swing of a more loose limbed sort of bloke. I play with one of the latter types, he hits the ball a mile and seems to build his power very gradually, he even uses regular flex in his clubs. On the other hand my swing is shorter and more strength.

[saevel25]

Doesn't matter, maximum speed is at zero acceralation no matter what type of swing you have. I know the guy your talking about, he's in my golf group. He makes alot of body rotation only motion, but what he does do is he accelerates in a short distance, and he uses his hands well to impact the ball at maximum speed. HE IS NOT ACCELERATING THROUGH THE BALL.

I mean, you can if you want, go ahead, your going to loose a ton of ball speed in doing so. There's no way around it, no matter what you do, to get maximum distance you must have acceleration of zero at impact.

[logman]

Hell, though, you'd rather be accelerating than decelerating........HHmmmm ? And another thing, if you've got the mentality that you're going to drive tjhough the ball and into the follow through powerfully then it has an effect on how you hit the ball......even before you hit it. Cmon, you know how well you hit the ball when you give it the big follow through, the Greg Norman follow through, the big Seve walk through...... throw the club towards the caddy(wife) grasping the putter as you stride, balls the size of melons to sink the almost unmissable 8 footer to claim victory on the last hole.......or is that just me?

Geez I love golf!

[NotBillCosby]

If you think about accelerating, then you won't decelerate...   That is the point.  Its easier to control the distance if you are always accelerating.  Especially for chipping and pitching this is important.  All you have to think about is how for to take it back and always accelerate to eliminate guesswork through impact.  For pitching and chipping, what you don't want to do is take it back the same amount and try to guess how much to accelerate the club to get the proper distance.

[saevel25]

The problem with thinking acceleration, its not a good tip for general use. I've seen countless amateurs hit duff chip shots because they think they have to accelerate and they end up loosing there wrist angle and duffing it, or they think acceleration and they lift up and skull it. I've seen amateurs have massive aggressive swings, but all there doing is lashing out loosing all there power early.

It might work for you, but its not good advice for everyone. If you have all the positions right, you don't need to worry about acceleration. Having a flat front wrist at impact with the hands ahead at the ball means you have optimized acceleration, especially if your on the correct swing plane.

Also, Amateurs don't need to worry about acceleration, they have some of the most violent swings i have ever seen. when i go to the tournaments to watch the pro's, i am always amazed at there effortless power. You go watch a driving range at your public golf course, those swings have no acceleration issues, they have a ton of other issues, acceleration isn't one of them.