Wide & shallow

[Todd Dugan]

So I hit down...... a LOT. And I'm trying to figure out exactly WHY. So I determine, with video, that the low point of my hand arc is in-line with my left armpit. But with respect to human biomechanics, I determine that, with the hands connected, the lowest point of the hand swing must be in-line with the shoulder center.......UNLESS, the left arm is "growing". And this is exactly what happens in many forceful swings......the arms become FULLY extended after impact due to the powerful outward pull of the clubhead and right arm straightening. So my left arm was SLIGHTlY bent entering the impact zone, but got stretched-out fully during and just after collision, extending the low point of the hand swing, and thus, the clubhead's low point. SO.....I decide to experiment by pushing my hands as far away from my body as I can throughout the swing.....WIDE. I'm thinking, if my left arm is already stretched out, my hands MUST come up sooner and so the clubhead low point will occur earlier...shallower Attack Angle. PRESTO! Probably went from like -8* to -4* INSTANTLY.

 

[bluebird]

Todd,


Sounds like you are heading in the right direction, it's all covered in Brian's Ideas video. If one would imagine a cross section of cam lobe profile imposed on a golfer's front view, with the center axis the shoulder complex center and the pointed lobe pointed at the right thigh. The arms would lengthen as the coupling point passes the lobe tip, then shorten again as they are ideally locked to the cam path by you. Now when one adds back extension and leg jump, to maintain the cam path, the parametric appears. So the arms shorten and the shoulder is no longer in line, and there is no circular arc.
Hope that helps.

 

[Kevin Shields]

Be careful, or people who think a wide hand path causes throwaway and a loss of clubhead speed might actually begin to understand something. I like your description.

 

[mgranato]

Unfair, Kevin. If you had double digit clubhead speed, maybe you would treat every single MPH as your precious too? All you people who only think great golf is played on the course are soooo condescending.

 

[zaf]

My question is how did you determine AoA without Trackman or equivalent. As Brian has frequently said...Video CANNOT give you AoA.

 

[Todd Dugan]

Todd,


Sounds like you are heading in the right direction, it's all covered in Brian's Ideas video. If one would imagine a cross section of cam lobe profile imposed on a golfer's front view, with the center axis the shoulder complex center and the pointed lobe pointed at the right thigh. The arms would lengthen as the coupling point passes the lobe tip, then shorten again as they are ideally locked to the cam path by you. Now when one adds back extension and leg jump, to maintain the cam path, the parametric appears. So the arms shorten and the shoulder is no longer in line, and there is no circular arc.
Hope that helps.

No, I didn't follow that at all. How 'bout this......the low point of the lower tip of a double pendulum will be in-line with the axis of the upper rod, so long as the lower rod does not pass the upper rod sooner, and because the upper rod is a fixed length?

 

[Todd Dugan]

My question is how did you determine AoA without Trackman or equivalent. As Brian has frequently said...Video CANNOT give you AoA.

Its pretty easy to tell if your hitting down more or less. Comparing two centered impacts with the same club, when one produces a higher launch angle and shallower divot, then the AA is less descending. I threw the numbers out because I have worked with TrackMan, and have a pretty good feel for its measurements. By the way, I could always shallow my Attack Angle by positioning the ball farther forward. But I had to play the ball WAY forward. This technique allowed me to shallow-out with the same ball position.

 

[bluebird]

No, I didn't follow that at all. How 'bout this......the low point of the lower tip of a double pendulum will be in-line with the axis of the upper rod, so long as the lower rod does not pass the upper rod sooner, and because the upper rod is a fixed length?

Todd,

It appears we are looking at two different hub path/swing models. One of the two hub path models will help you with swallowing out the angle of attack, one will not. You pick which one helps you. As far as the length of the upper pendulum, if you bend one or both of your elbows, doesn’t the upper pendulum length get shorter? Another consideration is that all the joints in your body can raise and lower the upper pendulum pretty easily. I struggled with your model for eight long years and it is no stranger to me, just trying to help.

 

[bluebird]

Be careful, or people who think a wide hand path causes throwaway and a loss of clubhead speed might actually begin to understand something. I like your description.

Kevin,

Thanks, use it if you wish, Brian gets the credit, and you were very helpful also.

John

 

[bcoak]

Isn't ther a TGM term for a wide backswing? Remember the thought of trying to straighten the right arm on the BS.

 

[Todd Dugan]

Todd,

It appears we are looking at two different hub path/swing models. One of the two hub path models will help you with swallowing out the angle of attack, one will not. You pick which one helps you. As far as the length of the upper pendulum, if you bend one or both of your elbows, doesn’t the upper pendulum length get shorter? Another consideration is that all the joints in your body can raise and lower the upper pendulum pretty easily. I struggled with your model for eight long years and it is no stranger to me, just trying to help.

I'm open to other models, but the "traditional" double pendulum model is useful for study. It has a fixed axis to the upper rod, fixed rod lengths, and the lower rod does not pass the upper rod before equilibrium (low point). Obviously, the human golfer can disrupt these mechanics in many ways. but if he doesn't, the low point of the "bob" (tip) of the lower rod will be in-line with axis of the upper rod. That is my point.

 

[Billy McKinney]

Isn't ther a TGM term for a wide backswing? Remember the thought of trying to straighten the right arm on the BS.

Extensor action or Right Forearm Takeaway.
GSEM (r)