the knees - another accumulator
 

TGM has been fairly content with the 4 accumulators, however, with the increased science behind movement patterns and ground reaction forces....... could the knees be considered an accumulator?

All accumulators create stored energy which is then released: flexion and extension of the knee joint.

All accumulators have pressure points in which they are driven into or against: the feet into the ground!

I had this discussion with an oldschool TGM'er who described the knee antion as part of what drives the pivot, and therefore is part of ACC4. It made sense.. at the time.

ACC4 is more of a rotaty pressure which increases not because the arm is forcing itself on the chest, but because the ribcage/chest/upper torso is driving into the arm.

If the knees flex and extend along a vertical plane, then can assist the rotation but it isn't fully rotation.

So what would make them NOT be considered a Power Accumulator?

Would Brian Gay's impact position (and Ricky Folwer BTW - legs almost fully extended) not show us that he has increased the angle in his knee flex therefore using the ground to accumulate and release energy ?

I think you have a point here. Straightening the right knee does something very similar to the pivot as straightening the right elbow does to the primary & secondary lever assembly. And straightening the left knee does some of the same. Depending on knee action of course.

But the feet are in this regard pure power generators as there is no power generated below the knees to accumulate and release later. They do not release stored energy. They just work the pivot and the levers.

The power accumulators release stored energy. They transmit accumulated energy from the moving pivot and delivers it to the ball. And some of this energy was produced by the knees stretching.

While the power accumulators don't really accumulate power, they are the enablers of accumulated energy being transformed to force & speed through the ball. And to some extent they are power sources themselves.

There's plenty of mentioning of the role of the pivot and the feet in the book. The power generat from the large bodyparts aren't neglected at all.

Hi Slicer,

"Vertical Ground Forces" are a big part of the golf swing, and are taught in many different ways. Homer Kelley once said that he expected the golf swing to continue evolving for all time. That doesn't necessarily mean he expected us to redefine the structure of his work.

IMHO, the Power Package and it's Accumulators and Pressure Points are very well defined, and understood by anyone who studies the work. I don't think the definitions need to be messed with.

On the other hand, what a great add on for instructors who understand it!

I never understood what I was supposed to feel through the ground, and how powerful it could be until YODA showed me the basic MacDonald drills, specifically the one dealing with Left-Right-Left-Right. What an eye opener! There were times of course over my career that I had the "feeling", but until YODA I didn't understand why.

My opinion may not be popular in this new high tech world of teaching, but I want to learn the Machine as Homer Kelley intended, then go from there and form my own opinions. Believe me, I read and try to understand EVERYTHING I can, and I always come back to this basic structure.

Kevin

Kev, I agree. I enjoy sticking to what HK describes and keeping it 'pure'

It does keep things simple.

The purpose of posing this question on this site is so that the true machinists here can give me their feedback as to how they see it. I mean... if accumulators are power sources with associated pressure points, the knees fall into this assumption.

I don't mean to say the yellow book is wrong - just a fun discussion!

I understand my friend, just my opinion on what I agree is an interesting topic for discussion.

Cheers,
Kevin

The Knees are a component of the Pivot . . . I understand how people could think that the knees spine etc. would be an "accumulator" . . . some have described this as the 5th accumulator. However . . . if we are going to talk Machine we must restrict our discussion to the components as defined by Mr. Kelley. See Chapter 6 . . .

The Power Package isolates and DEFINES the function of the HANDS AND ARMS in propelling the clubhead into inpmact. So the knees and spine AIN'T a part of the Power Package . . . but they do have a function in regard of delivering/powering via the #4 pressure point.

Force is applied to the ball through Lever Assemblies. Power is applied to Lever Assemblies through Pressure Points. Power is applied to the Pressure Points by Power Accumulators.

Soooo . . . Mr. Kelley defined the Lever Assemblies/Power Package in such away that DID NOT include the Knees and spine. So they don't get to be called an "accumulator" . . . HOWEVER.. . . that DON'T reduce their IMPORTANCE . . .and BEYOND that . . . it certainly DON'T mean that Mr. Kelley didn't understand their importance and/or how they WORK. See swinging from the feet . . . . this could be "incomplete" from a biomechanics/kenetics point of view . . . BUT . . . let's give Mr. Kelley a huge amount of credit for being waaaaaaaaay ahead of his time. He may not have given us all the details with regards to joint function etc. . . . but he nailed a TON of it from a conceptual stand point. Ground breaking stuff . . .

Very well stated Sir.

Kevin

I give HK a ton of credit for identifying different components and variations where by not saying a particular way is wrong.

So, from an Opinion perspective, why would HK claim the power package was only accumulators and pressure points above the waist?

For discussion sake, we have 3 pressure points in the hands with 2 accumulators. If the hands can have 2, why would the pivot be classified as only 1 power source when there are multiple components and segments to the pivot itself?

The point is not that they are above the waist. The point is that they deliver power to the levers.

Remember that in a swing, the pivot does basically all the work. A firm extensior action doesn't add work. It just enables better energy transfer from the pivot.

According to said above the pivot doesn't power the club solely through pp 4 either. There is a reason that the three other power accumulators are labeled accumulators and not something else, like power generators. While Homer to some extent chose to define his own terms, there are some very clear relationships towards textbook mechanics and mechanical engineering in TGM. And it is hardly a coincidence that he used the term "accumulator".

Very powerful swing stroks can be produced without engaging pp4, and the pivot basically generates all the power. I agree 95% with what 12 piece bucket wrote earlier. But his indication of pp4 as the only channel for transmission of pivot power is something I disagree with - if that's what he meant.

Homer's terminology works pretty well. And it works even better if one spends two minutes thinking about what an accumulator is, and what it does. An accumulator isn't a device that produces work. An accumulator is a device that stores energy and release it when it is called for. Big difference.

Energy generated by the pivot is accumulated as mass-velocity in the pivot. This mass-velocity, this energy is then released to the lever assembly. Through all the pressure points. By means of all the accumulators used. I don't think Homer would have used the term accumulator if he figured that only acc 4 had something to do with accumulation and release of power. Because it would be inconssistent terminology and because it would be wrong. Homer was a smart guy.

In a pure swing the right arm will work as a pure accumulator in the form of extensior action. Just contributing to the integrity of the flying wedges while the pivot with the big muscles does all the work. In a hitting stroke the right elbow will still be an accumulator but it will also do work on it's own. The active thrust. I doubt that any of the other accumulators do any significant amount of work of their own - unless a very special stroke is called for. The hands are basically monitors and passive clamps - and there isn't much pp4 can do alone either. What the four accumulators have in common is the ability to channel energy accumulated in the pivot towards impact.

Remember he defined the power package as the HANDS and ARMS . . the pivot power being transfered via #4 pressure point. He chose to restrict the power package to the hands and arms as defined in chapter 6. However, that doesn't reduce the importance of the pivot (or its individual components) and it doesn't somehow mean that he didn't "get" the pivot.

As far as the pivot stuff is concerned you know that you and I are on the same page . . . but I think Mr. Kelley would be on the same page as well. No question that he understood that "power" is in the pivot via the individual lagging/out-of-line to in-line components . . . but the Power Package he defined as the arms hands and club. But I think it is a mistake to think that Mr. Kelley saw the pivot as "one power source" . . . he understood the components and their relationship to produce the largest radius via the segments going from out of line to in line from the feet up. Was the description incomplete . . . yes . . . but did that mean he didn't get it . . . no.

knee action and how it powers the pivot
 

I tried to change the name of the thread to keep the language as per HK. the knees are not considered an accumulator as per TGM so lets leave it at that. if HK wanted them there, he would have described them as such. I mean.. he had 6 editions, right?
Bernt - did I misread your post? the FACT is that they are above the waist. The point is that they deliver power to the levers.. Great post BTW.. and thanks to Bucket.

As per bucket's description, which matches the way someone else described it, the knees can facilitate power to the pivot, and as such, to pp4. Simple.. Easy.. Makes sense.

Would it be fair to say that the knees are a one of many segments that power the pivot? knees are independent of hips, which are independent of the ribcage/shoulders & chest.

ACC4 is described as the MASTER ACC, so I am wondering if it is the master due to the power source (it would be the start of the kinetic chain) or is it because it's the most inner part of the circle of the swing, and therefore has a major impact on the rest of the power package? (lots of meat in there....)

I'm pretty sure we're on the same page . . . but how would power from the pivot be transfered from the pivot to the power package/lever assemblies in points other than pressure point #4? Would you say there are some points missed in the right arm? if we are restricting our discussion to the power package (arms hands club) as Mr. Kelley defined it?

For the sake of discussion . . . here is the power package and "triangle" defined by Mr. Kelley.

DEFINITION

6-0 GENERAL The Power Package concept isolates and defines the functions of the Hands and Arms in propelling the Clubhead into Impact. The Power Package consists of the Arms and the Club – as discussed herein – and includes the four Power Accumulators, the four Pressure Points, their Loading and the Clubhead Lag. There is no Stroke which does not include a Power Package Assembly and the five-step sequence of their operation – Accumulation, Load, Storage, Delivery and Release.

STRUCTURE

6-A-1 THE TRIANGLE ASSEMBLY The Power Package is basically a Triangle and this form puts it under the Law of the Triangle. The Straight Left Arm forms Side One, the Shoulders form the second Side and a line from the Right Shoulder to Hands forms the Third Side – whether the Right Arm is straight or bent. So the shape of the Triangle can be changed only by changing the length of the Third Side. Also, regarding Structure, study 6-B-1-D and 6-B-3-0-1.

So I reckon to use your term . . . it is above the waist . . .

Here's the stuff on #4 . . . I'd say it's master because the release sequence is always 4,1,2,3 regardless of the procedure used . . . so if 4 is loaded then it has to release or the others can't release.

RADIUS POWER

6-B-4-0 THE FORTH POWER ACCUMULATOR The angle formed by the Left Arm and Left Shoulder forms the Forth Power Accumulator. It is not only an independent Power Accumulator, but its Triggering function as the Checkrein of the Right Elbow is also vastly important and it thus can be the Accumulator of the Accumulators – or Master Accumulator. Also see 2-M-4.

As Accumulator #4 it is Pivot (Body) Power supplying the initial acceleration of the Downstroke to throw the Lever Assemblies toward Impact by the Thrust of the Shoulder Turn. See 7-13. Another major contribution to Impact Power is geometric – it is the first link in the Swing Radius power train between the Club and the Feet.

“Left Arm Power” in any form or amount can still be considered #4 Accumulator Action. Otherwise it actually substitutes for the Pivot to introduce the circular motion required to produce Centrifugal Force

6-B-4-A MAXIMUM POWER is obtained by using maximum On Plane Shoulder Turn Thrust against Pressure Point #4 per 7-19, and maximum Swing Radius (6-B-0).

6-B-4-B ZERO ACCUMULATION is either no Shoulder Turn or the use of Accumulator #1 alone for actuating the Primary Lever Assembly.

6-B-4-C MAXIMUM TRIGGER DELAY is achieved by using either the Standard or Delayed Pivot (to increase the Lag of the Downstroke Shoulder Turn) with a Snap Loading Action (per 7-19-3 and 10-22-C) followed by a Snap Release (10-24-E) with a Pitch Basic Stroke (10-3-B). For Hitters the essential difference is that Loading is per 7-19-1.

I'd like to think so.

I am learning a lot from your posts. :study:

(But I still think I understand ordinary machines better than golfing machines though.)
Structural support and aligments are key here. G.O.L.F: Geometric Oriented Linear Force. It is the linear forces that produces swing speed. The radial forces (the pull from the swing center) only changes the direction. The right side delivers linear forces through pp#1 and pp#3, weather the work is done by the pivot alone (swinging with extencior action) or also by the left arm as in a hitting stroke. Of course pp# 4 delivers linear force too by pushing the primary lever.

Even pp# 2 delivers linear force. Not linear with reference to the primary lever but with reference to the swing center. If the right arm was hanging from the neck it would only be able to deliver radial force. But luckily for us it is attached to the shoulder and is therefore pulling the club with an offset from the swing center. So as long as we're driving that pivot...

I think you nailed it with your quote of DEFINITION and STRUCTURE above.

The left shoulder joint
 

The left shoulder joint is IMO very significant in powering the swing. Its offset to the swing center means that it produces linear force and therefore swing speed by simply pulling the arm. I'm not referring to the shoulder throw enabled by pp#4, but the continous pull from the shoulder throughout the stroke.

There is some serious lag between the left shoulder and the left arm at the top. And also some serious lag pressure in the shoulder joint throughout the downstroke if the alignments allows it. The rigidity of the shoulders has a similar effect as a very sturdy pp# pressure point and totally dictates it to keep up with the pivot. No matter what resistance it faces during release and impact.

The "lag pressure point" in the left shoulder joint enables a throw-out action of the whole lever assembly. And it doesn't require pp#4 assistance to work either. The shoulder joint delivers power from the pivot to the ball. Just like any other power package.

But the left shoulder movement and location is geometrically misfit - too flat and above the inclined plane. So the shoulder needs help. If the left shoulder were left alone to power the club it would possibly pull the club outside the inclined plane. When the swinger rotates pp#3 to the aft of the clubshaft he will promote a downwoard directed force from pp#3 in the down stroke. More downward than the "from behind" pressure in a hitting stroke. This downward force will to a certain extent balance out and redirect the outward tendency produced by the left shoulder. Some of us use hip tilt, sequenced release, plane shift, pressure point rotation and basically any legal trick in the book to conter-balance the outward biased delivery from the left shoulder.

If we were to vote for an accumulator no#5 my vote would probably go to the left shoulder joint. Can't live with it, can't live without it.

Right Shoulder
 

As you stated at the TOP the left shoulder is not in a strong position. It is flat and above the swing plane. The right shoulder is in the strong position. Ready to drive down, out, and around on plane. START DOWN is shoulder acceleration, Right shoulder. The right shoulder accelerates and the left shoulder moves in accordance with the right. Check out 1F
As far as linear versus radial force look at 2K, endless belt. Over the years, I have learned to appreciate the importance of the drawings and pictures in the yellow book. The straight side of the belt is linear. Slow steady pressure. The pulley part is radial. Pure acceleration.

If the left arm was hinged to the pivot at the swing center (as it is in figure 1L) it would only be able to deliver radial force to the primary assembly, i.e. keep the primary lever assembly rotating.

But the left arm is hinged ahead of the swing center and therefore able to pull the primary lever assembly forward and not just around. If you feel any reacton from the club in the left arm, the left arm is tragging the club - not only in circles but also forward. The release of the primary lever assembly is a powered release. It does the same kind of work as the right side, only in a different manner.

The endless belt, ref 2k shows linear travel versus radial travel. That is not at all the same as linear versus radial force.

If the endless belt is moving at constant speed, the club will also have a constant speed during it's linear travel. That means that the club is not subject to any forces at all. But matter changes when it takes the curve. The change of direction is caused by a radial force. This force doesn't increase the speed; it only changes the direction.

If no linear force is applied by the belt on the club, the butt end of the club will slow down and the club face end will speed up. So the velocity energy in the lever is redistributed. (Correspondingly, the hands slow down as the clubhead picks up speed.) But the total mass-velocity of the endless belt-club will remain constant.

If the club speed is increased and not just redistributed, it's due to work from a linear force. (Linear force in the TGM sense; A force that works in the same direction as the club at any moment; in other words a tangential force).

The left shoulder pull does both those things. It can't do one without the other.