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.