Jack Nicklaus on a Centered Pivot

[johnthejoiner]

Originally Posted by motteler621

here is a couple pictures of my swing from today, as you can see Im centered in my head, chest and hips. My head does turn slightly to help with my body turn, lots of good players did and do this too. This is same swing as on scale guys.

top of backswing

into downswing

your taller than i imagined

[johnthejoiner]

Originally Posted by uttexas

I applaud your scale study. What you measured was a change in force/pressure. Put your foot on a scale and push down on it with your muscles, the scale's numbers will go up. By centered, I understand that to be mean mass centered. At the top of a good backswing, the good player will be pushing off the rear instep a lot, so yes, in a centered swing at the top of the backswing, the scale under the rear foot will read high numbers.

For some people, "weight is the force of gravity", and for others "weight is what a scale reads".

[newtogolf]

A more accurate test would require two scales so that you could measure the individual weight on each leg and see if there's a shift and if the combined weight remains the same, is less or more.

[motteler621]

A more accurate test would require two scales so that you could measure the individual weight on each leg and see if there's a shift and if the combined weight remains the same, is less or more.

you just do the same thing but on the front foot,,,, did it. At address about 75, through backswing decreases in weight alot and then jumps up alot into downswing. I can post a video later if you would like.

[Stretch]

Originally Posted by newtogolf

A more accurate test would require two scales so that you could measure the individual weight on each leg and see if there's a shift and if the combined weight remains the same, is less or more.

As posted above, there are very accurate, commercially-available products that do just this.

http://www.swingcatalyst.com/

Or you could just make shit up like this guy does. Chi wiz!

[sean_miller]

Originally Posted by uttexas

I applaud your scale study. What you measured was a change in force/pressure. Put your foot on a scale and push down on it with your muscles, the scale's numbers will go up. By centered, I understand that to be mean mass centered. At the top of a good backswing, the good player will be pushing off the rear instep a lot, so yes, in a centered swing at the top of the backswing, the scale under the rear foot will read high numbers.

Step on two scales and push one foot down. One weight goes up while the other goes down. I think that makes sense.

[jamo]

Step on two scales and push one foot down. One weight goes up while the other goes down. I think that makes sense.

I think he's talking about the fact that acceleration will change the scale readings. When you accelerate downward, the sum of the scale readings will be greater than your weight.

[newtogolf]

Exactly, The nature of spring based scales prevents them from determining the weight accurately over such a short period of time as that of a golf swing.

Originally Posted by jamo

I think he's talking about the fact that acceleration will change the scale readings. When you accelerate downward, the sum of the scale readings will be greater than your weight.

[motteler621]

Exactly, The nature of spring based scales prevents them from determining the weight accurately over such a short period of time as that of a golf swing.

yea, but the fact is the same. You would compare the amount of weight force you are using when you push into the ground on that foot. Compare the foot force on backswing and downswing for both feet and get the percentages that way. I have a strong feeling they will be very close to basing them off ur total weight

[newtogolf]

Yes and no, if I place my hand on a scale, it will weigh x.  If I then apply force using only my muscles the scale will reflect an increase in weight, but my hand hasn't increased in weight.  This is the case where force doesn't equal weight.

Originally Posted by motteler621

yea, but the fact is the same. You would compare the amount of weight force you are using when you push into the ground on that foot. Compare the foot force on backswing and downswing for both feet and get the percentages that way. I have a strong feeling they will be very close to basing them off ur total weight

[motteler621]

Yes and no, if I place my hand on a scale, it will weigh x.  If I then apply force using only my muscles the scale will reflect an increase in weight, but my hand hasn't increased in weight.  This is the case where force doesn't equal weight.

yes I know. I'm saying compared force numbers of front foot and backfoot to each other for percentages of weight ratio. I think it will be close to measuring individual force of each foot to body weight for percentage. Il do it tonight and post it, it will be a more accurate percentage, but my guess is it's close to what I have now

[sean_miller]

One could argue it has (hasn't gained any mass though). Either way, it doesn't prove much wrt a golf swing.

Originally Posted by newtogolf

Yes and no, if I place my hand on a scale, it will weigh x.  If I then apply force using only my muscles the scale will reflect an increase in weight, but my hand hasn't increased in weight.  This is the case where force doesn't equal weight.

[iacas]

Originally Posted by uttexas

I applaud your scale study. What you measured was a change in force/pressure. Put your foot on a scale and push down on it with your muscles, the scale's numbers will go up. By centered, I understand that to be mean mass centered. At the top of a good backswing, the good player will be pushing off the rear instep a lot, so yes, in a centered swing at the top of the backswing, the scale under the rear foot will read high numbers.

Exactly, uttexas. PRESSURE != WEIGHT.

"Weight" does not involve use of muscles. Weight is a static value. Freeze any player at any moment and put the scales under their feet. That'll tell you their "weight" on each foot. That's precisely why you can lift your left foot but still have 50% of your weight (or more!) on that foot.

Pressure is a dynamic measurement. Your weight is nowhere near 90% as some asserted previously, and Nicklaus never got anywhere near 90%.

And yes, there are teachers who teach that you translate, move, drift, etc. "off the ball." "Get behind the ball" you'll hear. Left shoulder over your right knee/foot is another. There are more. And a lot of golfers will try to do this, too, sometimes because they've heard they have to "get behind the ball" and sometimes because they're "trying to stay in their spine angle."

I made a video today. It may be irrelevant now... I think some of you are getting this now. Weight is not pressure.

[Harmonious]

Originally Posted by uttexas

I applaud your scale study. What you measured was a change in force/pressure. Put your foot on a scale and push down on it with your muscles, the scale's numbers will go up. By centered, I understand that to be mean mass centered. At the top of a good backswing, the good player will be pushing off the rear instep a lot, so yes, in a centered swing at the top of the backswing, the scale under the rear foot will read high numbers.

Isn't that exactly what motteler was saying?  The force on his back foot (measured in pounds) was much higher at the top of his backswing as he pushed off. Do you think the force Nicklaus exerted on his back foot (measured in pounds) would be somewhat similar?

[Harmonious]

Originally Posted by newtogolf

Yes and no, if I place my hand on a scale, it will weigh x.  If I then apply force using only my muscles the scale will reflect an increase in weight, but my hand hasn't increased in weight.  This is the case where force doesn't equal weight.

Your hand's mass has stayed the same, but the force (weight) has increased. Force equals mass times acceleration. In your case, the acceleration is gravity plus whatever external force you apply to your hand.

[johnthejoiner]

Watching a young jack Nicklaus when he was really going after one was the most dynamic move in sport

[iacas]

Originally Posted by Harmonious

Isn't that exactly what motteler was saying?  The force on his back foot (measured in pounds) was much higher at the top of his backswing as he pushed off. Do you think the force Nicklaus exerted on his back foot (measured in pounds) would be somewhat similar?

No. Weight and pressure (force) are not the same.

[uttexas]

Isn't that exactly what motteler was saying?  The force on his back foot (measured in pounds) was much higher at the top of his backswing as he pushed off. Do you think the force Nicklaus exerted on his back foot (measured in pounds) would be somewhat similar?

I like the F=ma explanation. Nicklaus as the example in this thread. Relative to address position, his body mass distribution is about 50/50. Relative to the center of his stance, about half of his body mass is behind stance center and half is ahead of stance center. The top of the backswing is a dynamic position. He has been straightening his rear leg (pushing against the ground) and at the top is leaning into his front side, so yes he is exerting force through his back foot into the ground. Nicklaus at the top=50/50 centered mass See the big butt in front of the ball [URL=http://thesandtrap.com/image/id/156782/width/1000/height/800][IMG]http://thesandtrap.com/image/id/156782/width/1000/height/500[/IMG][/URL] Now here's a picture of someone moving their mass center to the rear at the top [URL=http://thesandtrap.com/image/id/156783/width/1000/height/800][IMG]http://thesandtrap.com/image/id/156783/width/1000/height/500[/IMG][/URL] Nice video, iacas, in the previous post--really good explanation.