Into the rabbit hole, help me Mandrin!

[GPM1985]

Lately I've been thinking about the swing in terms of physics, succeeding mainly in confusing myself and wishing that I was a science major rather than an English major. These are a few questions I've come up with:

-If a lever is by definition rigid, are there any true levers in the golf swing? Obviously the club bends, so it isn't completely rigid, but enough so to transfer force. The individual arm bones are rigid, but the arm itself is not. Is the whole left arm a lever? Is it a lever only at certain points in the swing?

-Is the club a third class lever? If so, what would the fulcrum be? My guess is the left pinky, but I'm not sure.

-What other levers are at work in the swing, as you see it?

-People talk about how golfers with long arms have an advantage due to the longer radius. What exactly makes the longer radius an advantage? Could it be a disadvantage (work = force x distance)? Is the arm's length an advantage because it allows the radius to be shortened more?

-Is the clubhead's speed represented by radial acceleration? Is it possible to provide a (relatively) simple representation of the relationship between radial acceleration, centripetal force, and centrifugal force? Which is the most relevant for the golf swing, or are they equally important?

I have thoughts on a few of these, so if some of the questions seem to be leading to a certain answer it's because they are. I'm interested in Mandrin's response, but if you know the answer and can explain it conclusively in the simplest terms possible, then please drop some knowledge. Feel free to add questions as well, or to refine the ones I've asked.

 

[greenfree]

Quote: Is the club a third class lever? If so, what would the fulcrum be? My guess is the left pinky, but I'm not sure.

Could the fulcrum be between the hands?

 

[GPM1985]

Quote: Is the club a third class lever? If so, what would the fulcrum be? My guess is the left pinky, but I'm not sure.

Could the fulcrum be between the hands?

It just occurred to me that it might be the heelpad of the left hand, or more specifically the finger-side half of the heelpad. That might partially explain the need for the grip to be under, and not on, the heelpad.

 

[dbl]

-People talk about how golfers with long arms have an advantage due to the longer radius. What exactly makes the longer radius an advantage? Could it be a disadvantage (work = force x distance)? Is the arm's length an advantage because it allows the radius to be shortened more?

I had a question about length of ams for Mandrin as well.

A friend has short arms, like Raymond Floyd. My friend chooses club setup by lenthening his clubs..the irons about 2", and driver out to 48 inches. It seems to me he has an advantage of sorts in that for a given arm speed, that the short arm long shaft combo gives him higher clubhead speed than a person with normal length arms. Sounds right?

I'm thinking that as long as his wrists are strong enough, he is swinging out a long lever at the ball.

 

[mandrin]

Lately I've been thinking about the swing in terms of physics, succeeding mainly in confusing myself and wishing that I was a science major rather than an English major. These are a few questions I've come up with:

-If a lever is by definition rigid, are there any true levers in the golf swing? Obviously the club bends, so it isn't completely rigid, but enough so to transfer force. The individual arm bones are rigid, but the arm itself is not. Is the whole left arm a lever? Is it a lever only at certain points in the swing?

-Is the club a third class lever? If so, what would the fulcrum be? My guess is the left pinky, but I'm not sure.

-What other levers are at work in the swing, as you see it?

-People talk about how golfers with long arms have an advantage due to the longer radius. What exactly makes the longer radius an advantage? Could it be a disadvantage (work = force x distance)? Is the arm's length an advantage because it allows the radius to be shortened more?

-Is the clubhead's speed represented by radial acceleration? Is it possible to provide a (relatively) simple representation of the relationship between radial acceleration, centripetal force, and centrifugal force? Which is the most relevant for the golf swing, or are they equally important?

I have thoughts on a few of these, so if some of the questions seem to be leading to a certain answer it's because they are. I'm interested in Mandrin's response, but if you know the answer and can explain it conclusively in the simplest terms possible, then please drop some knowledge. Feel free to add questions as well, or to refine the ones I've asked.

GMP1985,

The body is a assembly of third class levers geared towards max movement and not for max force. The trail arm consist of two levers. If kept perfectly straight the lead arm is one lever but many golfers, pros included, let the left arm bend a bit at the top hence strictly speaking also two levers. Vardon used typically the lead arm as two levers.

The interface between club and arms is through hands and wrists. The hinge joint is somewhere in the wrists and the 'fulcrum' is somewhere on the shaft. The location of the fulcrum for either lead or trail hand is difficult to define and can even vary during the down wing. It is closely associated with the pressure points between hands and shaft.

For someone primarily using the last two or three fingers of the lead hand it is rather close to the butt. For others it might be more into the palm. Idem for the trail hand. There are various ways to exert torque through the hands. Independent or concurrent, lead and trail hand torques. Wringing lead against trail hand. Pushing with the trail hand by actively straightening the trail elbow, but also by letting the trail arm mass passively exerting pressure on the shaft.

With regards to length and hence mass of arms I have to do some calculations to be more assertive. But take note for the moment that indeed larger and heavier arms require more work to get them up to adequate speed and also that they will transfer somewhat less energy to the club prior to impact. But it also seems to be common sense that heavier members make it easier to create greater stability in one's swing.

It might come as a surprise but the centripetal/centrifugal force acting on the club don't exert any torque on the golf club. That is just another myth to be cleared and explained. Angular and linear club head acceleration come about solely by the tangential and centripetal acceleration of the wrist hinge joints, generated mainly by rotation of the core and transmitted through the arms. A small part is due to gravity.

The role of centrifugal/centripetal forces in golf kingdom has universally been treated incorrectly. However, I will not go into it for now, even when pressed with questions since I can do only one thing at the time and have other things simmering in the oven.

 

[mandrin]

I had a question about length of ams for Mandrin as well.

A friend has short arms, like Raymond Floyd. My friend chooses club setup by lenthening his clubs..the irons about 2", and driver out to 48 inches. It seems to me he has an advantage of sorts in that for a given arm speed, that the short arm long shaft combo gives him higher clubhead speed than a person with normal length arms. Sounds right?

I'm thinking that as long as his wrists are strong enough, he is swinging out a long lever at the ball.

dbl,

This is another type of question than by GMP1985. This has to do with length of clubshaft. Golf as life is a game of compromising. Long distance competitors probably will try the longest shaft which still keeps the ball in the fairway at least for a faire percentage. A longer shaft means more twist and deflection so you are looking for more trouble. However as I do some calculations for the influence of arm length and mass, I will throw in various club lengths as well.

 

[GPM1985]

Great stuff, thank you for taking the time to write that. Looking forward to more.

 

[Dariusz J.]

dbl,

This is another type of question than by GMP1985. This has to do with length of clubshaft. Golf as life is a game of compromising. Long distance competitors probably will try the longest shaft which still keeps the ball in the fairway at least for a faire percentage. A longer shaft means more twist and deflection so you are looking for more trouble. However as I do some calculations for the influence of arm length and mass, I will throw in various club lengths as well.

Mandrin,

Not necessarily - they use XXX shafts with prolly highest possible bend point; I cannot comment about torque though. They have 6 attempts in a round to place a drive between marks.
Lastly, even if I am sure it is stupid to remind you - on-center hits are more important than an additional 2" of lenght when one can't hit the sweetspot. The so-called PTR.

Cheers

 

[dbl]

dbl,

This is another type of question than by GMP1985. This has to do with length of clubshaft. Golf as life is a game of compromising. Long distance competitors probably will try the longest shaft which still keeps the ball in the fairway at least for a faire percentage. A longer shaft means more twist and deflection so you are looking for more trouble. However as I do some calculations for the influence of arm length and mass, I will throw in various club lengths as well.

Thanks. Hoping you mean as well, that you'll include different length arm lengths. Perhaps one shorter and one longer..or at least set up the equation(s) to have it the arm lengths as variables.

Appreciate it.