Ball Speed Magic Number for "big boy" golf

[art]

Art, I'm enjoying your posts. I think you mentioned before that the left (lead) hip needs to have a higher velocity than the trail hip on the downswing. I'm wondering how this relates to your comment above about vertical reaction forces remaining between the feet, and how this relates to weight shifting between the right and left foot in the downswing. Thanks.

natep'

Sorry for this delayed response. I appreciate the sincere and knowledgeable insights you have noted, so lets take them one at a time.

Left hip higher velocity than the trail hip is only necessary until impact with the ball, then the right hip will rotate forward, lifting the right heel off the ground in a classic follow thru. (Actually, I am still studying this area and believe the higher velocity of the left hip is only necessary until the peaks in the kinematic sequence, approximately 0.100 seconds before impact, and when the left arm is slightly below horizontal and the club is slightly past vertical). This sequence significantly improves the golfers lower body dynamic balance and stability margins.

Your comments about the left hip rotation, vertical reaction force location and weight shift are all inter-related, but are really easy to understand if you think of FORCE SHIFTS, instead of WEIGHT SHIFTS. Gravity, and the associated forces due to the golfers weight are absolutely the only forces while the golfers body is still. However, during the back and downswing, the vertical components of several centripetal force required reactions to rotating body elements affect these total forces and at impact often sum to values approaching twice the static body weight.

In actuality, these forces are not just vertical, but also appear as horizontal shear forces on the ground, so my simplified comment of the GRF being between the feet is only partially correct, but sufficient for the single axis force plates presently on the market. At any rate, with today's understanding and the ability to measure the golfers GRF's, ie Dynamic Balance System (DBS), WeightRight System, keeping the often used nomenclature of Center of pressure (COP) or Center of Gravity (CG) between the area under and defined by the left and right footprints probably indicates sufficient dynamic balance and stability margin.

However, stand by for some significant dual 3D force plate research/analyses that should uncover the disturbing effects of these additional shear forces, and what is additionally required for consistent and sufficient dynamic balance and stability..

 

[natep]

Sounds good!

 

[SteveT]

art:

In your area of study of the golfswing, what is the significance of the everchanging location of the body Center of Mass, as it relates to force and weight shifts within the golfswing? How do you locate it and how would you measure it's vertical height?

Thanks.....

 

[art]

art:

In your area of study of the golfswing, what is the significance of the everchanging location of the body Center of Mass, as it relates to force and weight shifts within the golfswing? How do you locate it and how would you measure it's vertical height?

Thanks.....

Steve,

The bodies center of mass in 3 dimensional space is dependent upon the bodies basic shape, and its posture. For instance, when standing straight up, the center of mass for a person of normal stature is inside the torso, and approximately between the 'belly button' and the spine. For 'full figured folks' it moves a little higher, and outward towards the belly button. BUT this location becomes quite different with the typical golf set-up position, and changes during the golf swing. To my knowledge it is calculated and depicted on the Taylor MATTs system as a function of time. As to its vertical position, most books on anatomy 'mass properties' will provide you with the center of mass of the body AND location in all 3 axes, but it is up to you to recalculate for various body postures, such as during the golf swing.

A word of caution, as you research foot reaction forces and especially ground reaction forces, are sometimes erroneously referred to as center of gravity(COG) points, and could be further misunderstood as center of mass (COM) points. As noted in my last post, these moving points are actually center of pressure points (COP). If you are interested, a great deal of research using force plates has been published in human and robotic 'gait' analysis defining these terms correctly, and applying the physics of motion involved. Unfortunately, golf swings ground reaction force analyses are often just the vertical component, and therefore just a part of the real forces and moments affecting the dynamics and stability of a golfer.

Back to the significance of your question as it relates to the golf swing using with a simple airplane aerodynamic analogy. While flying, if the center of pressure is coincident with the center of mass, the airplane will remain in level flight. If, with a configuration change ie. wing flaps extended, the center of pressure moves forward of the center of mass, the airplane will sustain a moment/torque, and develop a positive angle of attack. As fuel is burned, the center of mass of the airplane will change slowly, but in the case of the golfer, both the center of mass AND the center of pressure (from the ground reaction forces) change very rapidly creating a significant dynamic environment.

In conclusion, any torque/moment generated around an objects center of mass will have a similar effect, so the previously noted ground reaction forces around the golfers moving center of mass will develop similar moments possibly adversely affecting the overall 'dynamic posture' and performance of the golfer.

 

[SteveT]

art... thanks for that fulsome response, and I learned something more about COP and CoM..!!!

Permit me to selectively lift one of your observations and ask you to expand on it in the context of the golfswing, namely:

"The bodies center of mass in 3 dimensional space is dependent upon the bodies basic shape, and its posture. For instance, when standing straight up, the center of mass for a person of normal stature is inside the torso, and approximately between the 'belly button' and the spine. For 'full figured folks' it moves a little higher, and outward towards the belly button. BUT this location becomes quite different with the typical golf set-up position, and changes during the golf swing."

When I watch and play with "fat" men, I see them aborting their golfswing by blocking their hips approaching impact. I have speculated, because I'm not portly, that they 'autonomically' stopped their hip rotation because to continue aggressively would compromise their spine and spinal chord subjecting them to great stress. The brain will not permit it's spinal cord extension to be injured and will abort any attempt to do so.

The added momentum of slinging a 50lb/23kg mass within the kinetic chain would also most certainly limit their stability range. Their solution is to keep the lower body "quiet", which now seems to be fashionable in the golfswing world. Of course this alters the segmental velocity curves and produces a different solution to achieving clubhead speed.

What I find puzzling is how old pros with blown bellies can still play decent golf and not get sidelined with injured backs. I attribute this to the fact that they are hard-wired from youth in their golfswing and they have the ability to compensate for their additional avoirdupois...!!!

I would love to see a kinetic comparison of the swings of flat-bellied pros versus blown-belly pros, and how they differ..!!! Sorta like swinging with a full tank of gas...

 

[cwdlaw223]

Brian -

Does this work?

Just got back from hitting the new Rocketballz driver. Safe to say, I'll be buying one very soon. That speed wasn't a fluke. I suspect 120 max by the middle of summer. 115 was normal.

 

[BIGBALL]

Brian -

Does this work?

Just got back from hitting the new Rocketballz driver. Safe to say, I'll be buying one very soon. That speed wasn't a fluke. I suspect 120 max by the middle of summer. 115 was normal.

Wow! What is your current driver numbers?

 

[cwdlaw223]

Here is another shot from today:

I try to post only the good ones to make myself feel better. This shot went way left, of course, I aim way right so it would have been in the fairway. My mind is calm aiming well right. Just how it is for me along with my -4* closed clubface almost every time. You can play with "bad" impact numbers as long as they're consistent.

 

[OLIVER1]

cwd.
THose are some impressive speed numbers
How far do you hit it on average?

OK. I just saw the second screen shot. You, my friend, are a monster!

 

[cwdlaw223]

Do the opposite of what some say and you'll be fine!

I only posted the good ones in all fairness. I strugle like everyone else.

 

[SteveT]

cwdlaw ...!!!!!!!!!! Impressive numbers... and I too have a 300yd. carry.... 200yd drive and I pick it up and carry it an additional 100yds..

What I want to know from you is can you feather 6/7/8 irons from 150yds. ..... I can with great skill and accuracy. Where I lack is with the driver... which I may never conquer. Oh well... I must be happy with just beeeing a golfswing ex-spurt.

 

[natep]

He probably hits 9-iron or wedge from 150.

 

[SteveT]

natep... I know... but I was using myself as an example of my fantastic short game skills!!!

Sure cdwlaw can hammer a 9-iron from 150yds. ... but can he gear down his golfswing in a deliberate and accurate manner?! Big hitters like Sadlowski suck because they swing in only one speed and can't change it because they only have one operational gear.

I suppose one could deloft a 9-iron with a lot of forward lean or back positioning and attempt to vary clubhead speed, but that's risky.

I'm rather 'artistic' with my short irons ... but struggle with my longer clubs which are extended an additional inch and upright 2º for a relative 4-5º upright? I don't carry more than a 5-iron, and that sucker may soon be discarded too.

 

[cwdlaw223]

I've lived most of my life in the trees. My short game is better than my long game (except for the 30-60 yard shot). The driver has been a weakness of mine for years. Caused me to quit playing golf in college (driver yips). Brian stopped my duck hook and now I have confidence off the tee. Hooks still occur, but they don't kill my confidence. I usually hit 8 iron from 150. I can hit a 9, but I have to swing too hard. The 118 was much higher than normal. The higher the ballspeed the more precise you have to be to put the ball in play. There are plenty, plenty of people who can hit it by me. My brother can do it because of better launch conditions most of time (of course, he also played on the Golden Bear tour for two years). I've also been playing since I was 13 and have 27 years experience (40 sucks - want 25 again with some money). If you don't start out playing young the odds are severely against you. Golf isn't natural. Plenty of athletes who try to play and their athleticism doesn't work in their favor (except for baseball or hockey players - their skill set can transfer).

 

[Billy McKinney]

Steve T, Sadlowski played ONE Nationwide tournament and made the cut shooting 66 in the first round with 4 bogies. He shoots in the 60s all the time on his home course. I get what you're trying to say about finesse, but can we agree that the dude doesn't suck?

 

[SteveT]

cdwlaw.... you got that right... and I'm even a more extreme example of somebody who started golf in his late 40's.. and the conversion from basketball and tennis skills just didn't match the requirements of the golfswing. That and being tall and slim which creates massive anatomical handicaps, but I still have a reasonably pleasant game notwithstanding that I can't break 80 consistently.. and now my scores are creeping into the 90's..{{{shudder}}}

To learn golf I read out the library of all it's golfswing books... from the old masters to the 'golf my way' champions to the method and sham science frauds... and then I found SPS and my first scientific paper was Dr. David Williams' 1967 treatise on the kinetics of the golfswing... ***eureka***... now it was all beginning to make sense...!!! There were other good soft scientific books emerging, like LAWs and SLAP.

By injecting early science concepts into my golfswing I was able to improve significantly because I had an objective source, that plus my engineering brains, I was able to cobble together not only a golfswing but I instantly became a golfswing expert of sorts... and now I'm only an expert. How I envy you younger studs making use of TM and working with practitioners like Manzella.

Carry on ....

 

[OLIVER1]

Steve
Have you ever thought about taking a lesson with Brian?

 

[dbl]

What? Pay a couple hundred to the guy who provides the platform for SteveT? Whatever for? Myopic blind egotism does not require that!

 

[SteveT]

Steve
Have you ever thought about taking a lesson with Brian?

Yes I have, but since I can't conveniently go to NOLA and I doubt Brian would visit me, I can't realize my life's dream..!!!

Regardless, my golfswing is now on the decline due to age and nothing will save me from playing golf like Palmer and Nicklaus..!!!!

What? Pay a couple hundred to the guy who provides the platform for SteveT? Whatever for? Myopic blind egotism does not require that!

dbl joined the Manzella forum in October 2003, so he was probably one of those devout Homerites who attacked me (when I was "horton") and when I was telling Brian that Kelley was FOS and his Chapter 2 'science' was total rubbish... and then Zick confirmed that to Daniels. I guess the wounds are still festering in some here with a long memory... and a blind egotism to past beliefs.

 

[Shot Limit]

Shame. What with your part-time turns as a donkey-squiring, ballroom-sashaying, pole-dancing whizz, it sounds like an exotic locale like New Orleans would be the perfect place for you to make your mark.
Brian's loss, I suppose

Just for the record, there are no donkey shows in NOLA!

Don't want to set SteveT up for disappointment, hope that's not a deal breaker.......