ADD YOUR ANTI-SUMMIT II QUESTIONS RIGHT HERE!

[drewyallop]

Golf instruction orthodoxy holds that "the swing must start from the ground up". What scientific evidence is there that this is not the optimum way to start a swing?

 

[spmurph]

Is there going to be a thread similar to the one for AS I where we can ask questions to be presented to the panel?

 

[SteveT]

Brian... why can't we just send our questions to you by PM ...?

 

[wulsy]

Questions for the Summit

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I found the video interesting but not from a toss out point of view, more from the other IMO much more important issue he mentioned: the stabilisation on the chair not coming from the legs/feet.

This got me thinking about a phenominal strike I had last week with a wedge, normally my weak point. My ball was at the edge of a water hazard and I had to stand on the plastic cover of the water hazard which was muddy and very slippy to play the ball. Being the fool that I am, I decided to play it despite the risk of injury. I really just concentrated on not slipping while playing the shot and had the most automated release, sweetspot hit you can imagine and picked it clean away with no divot to 6 feet from the cancan. Beautiful.

So my point? A question for the scientists, Brian:

Should the INTENTION be to AVOID shear forces on the ground or to CREATE them?

 

[ZAP]

I have wondered about shaft deflections and how they would affect the golfers ability to hit the ball solid if a shaft was either too stiff or too soft for them. I ask this because my wife hit my irons (6.5 Project X) better than her own which have senior flex graphite. Just seems odd to me.

 

[spmurph]

Originally submitted by Darisuz is another thread but I also have interest.

The question is: does maintaining the tush line symbolizes biomechanically the optimal pelvis area motion ?

 

[Brian Manzella]

Is there going to be a thread similar to the one for AS I where we can ask questions to be presented to the panel?

THIS IS IT!!!!

Brian... why can't we just send our questions to you by PM ...?

You can.

But I'd rather them here.

But if you want to send an anonymous one, PM is fine.

 

[SteveT]

How does "out-toss" affect shaft loading at the start of the downswing?

Here are three graphs of typical downswing shaft loading profiles as determined from TrueTemper ShaftLab testing data:

The scientific study backing up these shaft loading curves is in Science and Golf II (1994), p. 259-64: The Dynamic Performance of the Golf Shaft During the Downswing - J.H. Butler and D.C. Winfield

Thank you....

 

[dbl]

Can TM measure face closing after ball has left, perhaps 1 inch after? Before also?

 

[mjstrong]

I'd love to know (perhaps for Paul Wood) how much the club face opens/closes during the impact interval on certain off-centre hits (1/4" toe hit for an iron and wood, for example).

 

[SteveT]

Toss-out is an applied force by the arms and hands. When is that force most effective, before or after the hips have shifted and rotated into the downswing, i.e. should the toss-out lead the body, or should the body lead the toss-out in the downswing?

Thank you .... SteveT

 

[drewyallop]

Assume there are three points in the downswing where force can be applied:

1. A toss at the top when the shaft is parallel to the ground and behind the head, grip end pointed away from the target.

2. Application of torque about the coupling point at or before the lead arm is parallel to the ground.

3. Pull up of the club to add parametric acceleration.

Of the total club head velocity achieved what proportion can be attributed to each stage?

 

[SteveT]

Since ASII will be examining the role of the body in the golfswing, could the scientific team please comment on this recent study that also has examined the role of the body in the golfswing and in particular the downswing?:

J Appl Biomech. 2011 Aug;27(3):242-51.

Rotational biomechanics of the elite golf swing: benchmarks for amateurs.

Meister DW, Ladd AL, Butler EE, Zhao B, Rogers AP, Ray CJ, Rose J.
Stanford University School of Medicine, Stanford, CA, USA.

Abstract

The purpose of this study was to determine biomechanical factors that may influence golf swing power generation. Three-dimensional kinematics and kinetics were examined in 10 professional and 5 amateur male golfers. Upper-torso rotation, pelvic rotation, X-factor (relative hip-shoulder rotation), O-factor (pelvic obliquity), S-factor (shoulder obliquity), and normalized free moment were assessed in relation to clubhead speed at impact (CSI). Among professional golfers, results revealed that peak free moment per kilogram, peak X-factor, and peak S-factor were highly consistent, with coefficients of variation of 6.8%, 7.4%, and 8.4%, respectively. Downswing was initiated by reversal of pelvic rotation, followed by reversal of upper-torso rotation. Peak X-factor preceded peak free moment in all swings for all golfers, and occurred during initial downswing. Peak free moment per kilogram, X-factor at impact, peak X-factor, and peak upper-torso rotation were highly correlated to CSI (median correlation coefficients of 0.943, 0.943, 0.900, and 0.900, respectively). Benchmark curves revealed kinematic and kinetic temporal and spatial differences of amateurs compared with professional golfers. For amateurs, the number of factors that fell outside 1-2 standard deviations of professional means increased with handicap. This study identified biomechanical factors highly correlated to golf swing power generation and may provide a basis for strategic training and injury prevention.

Thank you.... SteveT

 

[SteveT]

Question re "going normal".

When viewed face-on, the lead arm and clubshaft align going into impact to be "normal". However in a side view of the swing, there is still an obtuse angle between the lead arm and clubshaft. This was noted in the following study:

A three-dimensional examination of the planar nature of the golf swing
SIMON G. S. COLEMAN & ANDREW J. RANKIN
PESLS Department, University of Edinburgh, Edinburgh, UK
Journal of Sports Sciences, March 2005; 23(3): 227 – 234

Does this affect the 3D studies done by the scientific team, and how does this obtuse angle between the lead arm and clubshaft affect golfswing optimization? I believe this obtuse angle changes for each club.

Thank you.... SteveT

 

[SteveT]

Questions on segmental velocity in the kinetic and kinematic links.

Most recreational golfers are not flexible enough in their core to create an angular differential between the hips and shoulders (x-factor). In their backswing they may attain a 90º shoulder rotation, but only with a large hip rotation as well. In the downswing, the hips and shoulders rotate in unison without an x-factor 'stretch'. The hips and shoulders essentially form a single segment with the same angular speed.

How does this affect the summation of golfswing segmental velocities and how much is the loss of kinetic energy at the clubhead?

Thank you .... SteveT

 

[SteveT]

Driver clubhead design question:

We know that the 460cc driver head provides the recreational golfer with greater confidence to hit the ball. However, is such a large driver head optimal for higher swing speed players?

An oversized driver head may have a greater inertial and aerodynamic resistance for higher speed swings. Max COR can be maintained with smaller club faces, and smaller clubheads mitigate the stress on shaft tip loading. Surely, pro golfers don't need an 'expanded sweet spot', as do recreational players.

Thank you... SteveT

 

[magicmarker]

Can a player increase their swing speed by increasing the clubhead weight (a lot of lead tape). Now that I grasp going normal and pulling it just seems like a lot of younger more athletic players could really benefit by adding some weight to the other end of the pull.

 

[drewyallop]

Intuitively a taller player with long arms should be able, all other things being equal, to generate more club head velocity. Is this intuition correct? And if not why not?

 

[birly-shirly]

Is there any mechanical/ballistic advantage to using blades?

Is there any trade-off between clubhead forgiveness and performance?

What is a flip - and when is it a "fault"?

 

[Dariusz J.]

Hi Brian,

I would have lots of questions, however, the vast majority of them would require the presence of medical specialists (at least orthopedist and ophtalmologist). Thus, I'd narrow them to the following:

1. What are pros and cons of high and low swing planes ?

2. Is accuracy and distance mutually exclusive on a qui pro quo basis ?

2. When we can count on creating an universal scientific language for golf swing so that archaic language of e.g. TGM or Cotton or totally unscientific notions a'la "outtoss" or "tumble" can be replaced by medical-physical lingo that will be either easily understood or it would be easy to find the universal description in the net for all people in the world independent of age and language ?

Thank you in advance if you have time to ask the above questions. Big greetings to the scientific panel from Poland.

Cheers