Swing plane: TGM vs Hank Haney

[BerntR]

Earlier in this thread, I invited to comments regarding Hank Haney's swing plane concept and the TGM swing plane.

In short, in the Hank Haney swing, the shaft is always lying on a plane that is parallell to impact plane. But from the end and through the down swing the shaft plane points outside the target line. As the club approaches impact the shaft plane approaches the target line.

The responses were critical to Haneys ideas, and stressed the that the swing plane was a flat plane (as opposed to a curved surface) and that it went through pp3 and the sweet spot and impact all throughout the swing. Everything on a flat & inclined plane all the way through. At least that's how I read the responses.

I basically understood (I thought) and agreed with the replies at the time.

But recently it occured to me that gravity - the constant downward acceleration - the little "g" - the stuff that tries accelerate everything with 9.81m/s2 downwards - complicates this issue.

Please take part in a little thought experiment.

Assume first a pure rope handle swing done in a weightless environment. Ideally then, there will be a pure swing plane, where pp3, the sweet spot and the point of impact define the same plane in all positions from impact fix untill release. Obviously, the plane is inclined, but it is a pure plane in the sense that all possible vectors on the plane is either pointing parallell to the impact line , at the impact line or straight away from the impact line.

Now let's introduce our golfer with an unrestricted dosis of g acceleration. He, or she, is standing on a platform that is inert enough to enable a proper pivot, but the platform - and golfer and the club is free falling as the swing is executed. But the ball is sitting on the ground, waiting to be hit.

Obvious, the swing path will spiral downward as the swing progresses - since the golfer is falling down. We probably would have to drop this golfer quite a few yards above the ground in order to give here time to get back to impact before she hit the ground. And - equally obvious - the club would be pointing way above the impact plane (the ball) at the 9 o'clock position in the down swing. While the club path travels along a true swing plane with reference to the platform, it will be curved surface relative to the ball location. The swing path will be spiralling down towards the ball.

Then take this swing down to planet earth - under normal conditions. The feet now resist the g acceleration with an opposing force. So the body doesn't fall.

But this is a clean rope handle procedure. The clubhead will still be pulled towards the ground by gravity. And the golfer will do nothing to prevent the club head from dropping accordingly. The clubhead movement caused by gravity will come in addition to the movement caused by the rope handling procedure executed by the golfer.

The net effect of gravity will vary throughout the swing. At the top or end, the golfer only feels the weight of the club - and pp1, 2 and 3 is exerting a pressure opposing gravity force. At low point, the shaft will pull the club head up - and a part of this shaft pull will completely neutralize gravity. But in the middle of the downswing, where there's plenty of room for hands and clubhead to drop, gravity will have a big influence on clubhead acceleration.

I will not try to say exactly how this gravity accelleration influences the swing plane. It seems rather complicated and maybe it is also a matter of choice by the player. But I believe that gravity combined with a pure rope handling procedure will produce a swing path that is somehow curved.

In my mind, gravity will drop the clubhead relative to the plane that the pp3 is tracing through the down swing. To account for that, it is initially necessary to aim pp3 along a plane that point outside the ball and then let gravity move this pp3 path into correct position at impact.

This is by no means finished thoughts. And I will appreciate a few thorough responses.

Thanks,

Bernt

[starretj]

Gravity has no more effect on the clubhead during the downswing than it does at address or at any other point in the swing. Also, gravity can be symbolized by a vector acting thru the center of mass of the entire club which will be higher than the clubhead. You should be using gravity along with centrifugal force to guide the sweetspot to the low point of your swing.

[BerntR]

Starretj responded: Gravity has no more effect on the clubhead during the downswing than it does at address or at any other point in the swing.

In order for gravity to work the club, the club must be moved at least partly in the same direction that gravity points.

Work is force * travel *cos(the angle between the force vector and the travel direction). At address the angle will be close to 90* and the work gravity does on the club will be close to zero.

At address, the club may be moved left or right, while gravity still points at the ground. There's no way gravity kan work the club in this position. Midway down, the club is moving down, out and forward. Gravity will contribute to the down component. At impact, the down component is small and gravity can do very little to move the club. So the difference is big.

Quote: Also, gravity can be symbolized by a vector acting thru the center of mass of the entire club which will be higher than the clubhead.

But that's not enough. Gravity will move the hands and arms as well.

Quote: You should be using gravity along with centrifugal force to guide the sweetspot to the low point of your swing.

I agree. But bottom line is, long as the golf stroke is done on an inclined plane on planet earth, gravity will "try" to pull the club and the arms off plane during the swing. It will "try" to disturb the geometry and mess with the swing plane. How can it not?

We could be opposing gravity and "forcing" the club to be on a true plane throughout the swing. Sure it's possible. But I am more inclined to believe that we are accounting for this in our swings by directing our power packages' force vectors on a slightly flatter plane. And then we just let gravity lower the swing plane through certain parts of the down swing.

Please disagree and/or elaborate. These are not ready made thoughts.

[EdZ]

An interesting perspective. To the extent that I agree "gravity rides everything", I can see where the theory would evolve. If you were to completely allow gravity to account for the 'downward' component of motion, then yes - you would need more rotation, on a flatter plane to balance out the vectors and end up 'on plane'.