A big hello to everyone @ LBG (first post from a long-time though infrequent visitor).
The other day I got into a (non-TGM) discussion on the biomechanics of the golf swing. Part of that discussion was the 'plane' of the swing and subsequently the TGM principle) that the clubshaft is on-plane if either:
1. The butt end of the Clubshaft is pointing at the Line;
2. The length of the Clubshaft is parallel to the Line; or
3. The head end of the Clubshaft is pointing at the line.
From a biomechanics point of view we could not 'prove' (or disprove) why this is the case (as opposed to for example the opinion that the shaft is on plane when parallel to the inclined (address) plane throughout the swing). Reading through the relevant sections of TGM just now, I still can't substantiate as to WHY mr. Kelley defined being on-plane as he did.
Can anyone shed light on this? I'd very much like to know the foundation on which the TGM on-plane principle is based (preferably from either a mechanical physics or biomechanical pov).
mtr33 welcome to LBG
I only pretend to know what the heck Im talking about but:
While Homer identified the shaft as a good proxy for checking plane compliance, it is the longitudinal center of gravity , the Sweet Spot Plane that actually travels the Inclined Plane and makes contact with the ball. We dont hit the ball with the clubshaft ,hopefully. Although we have all done it on occasion. The dreaded shank.
Golf being a side on game makes the direction of force less apparent as compared to say .......darts or throwing a ball. But the physics are the same in that; the force must direct, align the c.o.g of the object/club/baseball to the target.
In regard to your question, to adopt a parallel plane method is by definition to aim the force away from the ball. It may look like a parallel plane when viewing a golfer from DTL but it isnt ideally. And any golfer who actually achieves this alignment must compensate for it or suffer the consequences. Complying with this parallel plane all the way down would see him miss the ball by an amount equal to the distance between the two parallel planes.
Another way of looking at this is to see that given any #3 Accumulator angle (the adoption of a left hand grip where the handle runs under the heel of the palm say as opposed to along the lifeline)...........that the left arm isnt on the inclined plane. Either at address or at Top. And so an actual On Plane position at Top would see an Inclined plane run from the ball to the #3 Pressure Point (its the #3 pp that is at the top of the longitudinal centre of gravity, the top end of the plumb bob that defines the sweetspot plane. The sweetspot on the clubface not being a static point but a movable point depending on where the top end of the plumb bob is. Like a balance point, a point without dimension, but I digress)...... But with the left arm above this plane!!!!
The good folks who when discussing theory, look (DTL) at the left arm as defining the inclined plane at Top have it slightly wrong. These folks include some of golfs absolute all time greats and their teachers. Its understandable, its close, it seems as if, but its not correct. However these golfers when actually playing for sure knew what it was to direct the longitudinal center of gravity, the weight in their hands, the sweetspot. And they did so with their left arms above the inclined plane that their sweetspots traveled. For full powered shots anyways, putting with the handle running along the life line would be a different story.
I only pretend to know what the heck Im talking about but:
That's all I'm doing too
Keeping the COG (sweetspot) directed at/in line with the point of impact, so the forces involved are 'aimed' correspondingly, is basically as far as I got. My reasoning was that keeping the sweetspot (shaft for simplicity reasons) in line with the hands & aimed at the baseline made sense, since it directed the forces applied towards the point of impact throughout the swing. It 'making sense' is not really conclusive though, I just couldn't get the mechanical physics part behind it airtight. Some more time in the book(s) required i guess.....
The crux of the reasoning can be found in chapter two. The line of compression.
As mentioned, 'the' plane is not the clubshaft, but the line of force between the hands and sweetspot.
that is a very critical part of TGM to understand.
For the physics of chapter 2 to create maximum compression, plane shifts should be kept to a minimum, because any shift is likely to decrease the force and efficiency of the line of compression (that said, there are more advanced discussions to be had around shifts and power generation, suffice to say from release point through both arms straight, any shift is not efficient).
As far as the body's role, keep in mind that it is the hands that must retain the relationship with the plane line, the body must just comply (see Ted's clip of his wacky pivot 'hit' in the gallery)
In a nutshell, the body must move in a way as to
a) allow the hands to retain the relationship to the plane line and
b) get the right shoulder moving down plane with as much of the body's mass as possible supporting impact while maintaining a stable center
__________________
"Support the On Plane Swinging Force in Balance"
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Actually, earth gravity could make a difference here. It is constantly pulling the club towards the ground and may support a gradual plane shift - or actually a spiral-like plane where an uncompensated single plane stroke is combined with a constant, vertical force.
It would be interesting to sort out whether the educated hands know where the ball is in gravity-less conditions. Surely there must be a golfing astronaut who could find out for us?
Gee - this plane stuff seems really complicated when you dive into the details.
The crux of the reasoning can be found in chapter two. The line of compression.
I thought the LOC was vital throught impact only. In that case, as long as the SS-plane is aimed at the impact point from release to follow though (between 3-4th parallels) proper LOC should follow, no matter the SS-planes orientation before reaching 3rd parallel. Keeping planeshifting to a minimun is obvious, but wether this is the case in any swing depends on the definition of "on plane" in the first place.
That for me is the crux, the fundamenals behind the "chosen" definition of being on plane are still somewhat unclear to me (from a geometric/physics view that is). My feel/instinct 'get it' but the mind is lagging behind.
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