Release – 2

[starretj]

From Mandrin's linear model, you might see that a reduced amount of effort, or effort applied at a certain time, can produce almost equal results for a golfer's clubhead.

"-2- From Fig 4d and Fig 5d it is seen that we have an effort of only 92 Joule in experiment 2 as 232 Joule in experiment 1, hence 2.5 times less work done, or 250 % less effort employed. Comparing the maximum velocities, notice that there is however, surprisingly, little decrease in maximum velocity, only from 36.1 to 28.4 m/s, hence only a reduction of about 28 % ."

Don't mean to be critical of the good work being done, but I don't consider a 28% reduction in clubhead velocity as being worth saving a little energy. I consider this a significant decrease in clubhead velocity. I have energy to spend, not clubhead velocity to spare.

Jim S.

 

[tongzilla]

Hogan's type of release (push release) is the best because it minimizes timing factor = making the swing more repetable, more consistent and more automatic.
It's not the best release type if someone wants to be a Re-Max champ, though. But this is of secondary importance.

Cheers

Please explain what you mean by a push release. Pushing with the arms?

I'm not saying it's the case here, but there are so many golf gurus out there who uses the cliche, "doing xyz (e.g. early set) will minimise timing factor and make your swing more consistent". If you practice anything enough you're going to get consistent.

 

[golfspike]

Please explain what you mean by a push release. Pushing with the arms?

I'm not saying it's the case here, but there are so many golf gurus out there who uses the cliche, "doing xyz (e.g. early set) will minimise timing factor and make your swing more consistent". If you practice anything enough you're going to get consistent.

Push release i think is a one plane jim hardy term where the right elbow is on or behind the hip . I my opinion Hogan had a snap release with perfect angle alignments and my query for Mandrin was to break down his release pattern if possible

 

[dbl]

Don't mean to be critical of the good work being done, but I don't consider a 28% reduction in clubhead velocity as being worth saving a little energy. I consider this a significant decrease in clubhead velocity. I have energy to spend, not clubhead velocity to spare.

Jim S.

Starretj, as you note, you would have power to spare...so...if you use the more efficient method and yet still input into the system the effort used in the inefficient method you will have a greater clubhead speed. In an analogy to a car, a model with higher efficiency MPG means you can travel a longer distance on the same amount of fuel.

 

[mandrin]

Steady State vs. Transient Modeling

Mandrin,

Ad rem: yes, I did refer to a hypothetical completely different model than a human golf swing in order to clear all aspects from the beginning.

Therefore, as I understand, you confirm that in a model I have described the outer rod will not release provided the inner rod is constantly turning with a stable angular velocity

Dariusz,

A steady state, by definition, is just what it implies - all things being in equilibrium. Hence your idea is not really very realistic.

A golf swing is completely different; it is really a transient phenomenon in which there is no equilibrium whatsoever.

 

[mandrin]

Chicken or Egg?

Mandrin,
so at the end you can say, that golfclub release because hands (or arms or shoulders or something closer to axis of rotation then club and the clubhead) will slow down prior or during release?

miki111,

Not quite true to state it your way. Normally proximal elements slow down as a result, not being the cause of this slowing down.

When proximal elements slow down they release their energy down the line and therefore eventually this helps to obtain greater clubhead speed.

The pro swing appearing so effortless is certainly one in which this flow from proximal to distal elements is close to optimum.

It is only for the young inexperienced aggressive male golfer that deliberately slowing down a bit would perhaps be good advice.

For any descent way to go about a down swing the slowing down happens by itself and is something which can’t be really avoided.

The idea of slowing down might end up inducing a scooping action whereas the hands better a be a bit in front of the ball at impact.

 

[mandrin]

dbl,

It is fun for me to read your posts as you seem to sense immediately the gist of things.

 

[miki111]

miki111,

Not quite true to state it your way. Normally proximal elements slow down as a result, not being the cause of this slowing down.

When proximal elements slow down they release their energy down the line and therefore eventually this helps to obtain greater clubhead speed.

The pro swing appearing so effortless is certainly one in which this flow from proximal to distal elements is close to optimum.

It is only for the young inexperienced aggressive male golfer that deliberately slowing down a bit would perhaps be good advice.

For any descent way to go about a down swing the slowing down happens by itself and is something which can’t be really avoided.

The idea of slowing down might end up inducing a scooping action whereas the hands better a be a bit in front of the ball at impact.

I agree 100%, but then I wish to learn why the hands slow down and what we should or shouldn't do to achieve "close to optimum flow from proximal to distal elements".

 

[nmgolfer]

Its nice to see some progress is being made here:

1) centripetal force = m v^2/r < which as Jake says is
proportional to velocitiy squared and
inversely proportional to radius

2) As Jake says, radius at any point in the downswing is determined by the instantaneous curvature of the path of the hands (kinematics). That path usually looks circular (but should look more like a converging spiral) so some people call it the "inner hub".

3) The golf swing is a gesalt... at no point are steady state conditions ever attained. To talk about steady-state conditions we would need to discuss damping (with out which steady state conditions would never be achieved) and we would need to introduce other forces such as aerodynamic drag acting on the shaft and club head. Its best not to think about what the angle would be between the shaft and the forarm under steady-state conditions because... the answer depends.

3) Mandrin says: ..."A release torque does not need centrifugal force or positive torquing with the wrists - simply pulling/pushing the golf club along can produce a release moment"...

Yes finally we can agree. Slowing hands are not needed either.

4) A "negative torque" is not required to prevent the club from releasing. Ever watch a dog chase its own tail? Do you think he's intentially bending his tail towards his mouth or are the dynamics such that the tail never gets released? Ok maybe that's not the best example but swinging a golf club is the same sort of thing. A decreasing hand path radius (coupled with accelerating hands) prevents an early release.

The club only begins to release when the dynamics (both kinematics i.e. hand path and dynamics (velocity/acceleration along said hand path) allow the club to release. So what controls the hand path? Many things: How straight or bent the left arm is; how the legs are used; how the shoulder girdle is used; whether pronation/suppination is being employed (and not everyone does); torso rotation; axis tilt I could go on...

Conclusions: What makes a good golf swing boils down to dynamics (hand path and hand velocity). There are millions of ways to acheive optimal dynamics i.e. swing a golf club but the best have a few thing in common: Decreasing hand path radius (think spiral); minimal movement of the swing center (instantaneous origin of hand path radius) which Austin followers think of as the c7 vertebrae (whether it there or not is debatable); athleticism... maximal use of all muscle groups... the young and fit will always out-drive the old and infirm. If you want the ball to go far, you're going to have to move your hands on the right path fast. Watch tiger.

 

[nmgolfer]

Then there's this notion of "momentum transfer".... CAREFUL!

When we discuss collisions the notion of momentum transfer most definitely applies. During the deformation and restitution phases of the collision the clubhead is most definitely "giving-up" (transfering) some of its momentum to the ball. But when the clubhead speeds up (during the release) while the hands slow down the hands are not necessarily imparting their momentum to the clubhead. Infact it could be the exact opposite happening. Lets try changing our thinking. Martin Luther King Jr. once said:

..."In a real sense all life is inter-related. All persons are caught in an inescapable network of mutuality, tied in a single garment of destiny. Whatever affects one directly affects all indirectly"...

Said another way and de-anthropormophized we can say: there is an unavoidable Push-Pull acting between all interconnect things. The sun pulls on earth but in turn the earth pulls slightly on the sun. Centripetal / Centrifugal. Action reaction.

What what causes hands to slow is an inablity of the human motor to generate the required force. The required force (to the keep the the hands moving fast) as the club releases, begins to increase. The club is pushing back back on the hands.

Now, I'm not saying that's it always always the case... Some golfers foolishly follow their instuctors' advice and intentionally try to slow their hands. I'm saying the dynamics are such that hand slowing can/does occur and that is does not mean momentum is being transfered in the convention (impact) sense. It simply means there's not enough horsepower available to keep them moving at the same speed. The cg of the club has moved away the center of rotation and therefore interia has increases... more torque is needed... more horespower.

 

[nmgolfer]

By the Way...

While I'm not, some golfers are fans of the bent left elbow ala Harry Vardon. Ted Jorgenson once showed that swing has potential (to generate more club head speed). In a nutshell, here's why:

With a bent left elbow at the top of the swing, the club is closer to the center of rotation (C7 vertabrae accorting to Austin followers). The moment of inertia (which can be thought of as "resistance to rotation") is heavily dependent on how far the CG is from the axis of rotation. Here's the pertinent dynamics equation

M = I * alpha

M = torque (force at end of a lever arm)
I = moment of inertia
alpha = angular acceleratation

So you get the system moving faster (alpha) given the same input torque if your moment of inertia (I) is smaller because the center of gravity is closer to the axis of rotation. But to keep it moving fast as the club begins to release and the left elbow begins to straighten and the moment of interia subsequently increase, you're going to have to find more torque (M). Torqe through a distance equals work... work per unit of time equals power. Bottomline? Get you butt down to the gym lard ass.

 

[Bronco Billy]

Lard Asses.......

By the Way...

While I'm not, some golfers are fans of the bent left elbow ala Harry Vardon. Ted Jorgenson once showed that swing has potential (to generate more club head speed). In a nutshell, here's why:

With a bent left elbow at the top of the swing, the club is closer to the center of rotation (C7 vertabrae accorting to Austin followers). The moment of inertia (which can be thought of as "resistance to rotation") is heavily dependent on how far the CG is from the axis of rotation. Here's the pertinent dynamics equation

M = I * alpha

M = torque (force at end of a lever arm)
I = moment of inertia
alpha = angular acceleratation

So you get the system moving faster (alpha) given the same input torque if your moment of inertia (I) is smaller because the center of gravity is closer to the axis of rotation. But to keep it moving fast as the club begins to release and the left elbow begins to straighten and the moment of interia subsequently increase, you're going to have to find more torque (M). Torqe through a distance equals work... work per unit of time equals power. Bottomline? Get you butt down to the gym lard ass.

The Lard Asses(Fat Guys,FB Centers,Right Fielders,Etc.) Won't Lose Weight at the Gym but They Sure as Hell Will Hit the GD Golf Ball Farther...... Have a Great Day With Your New Found Knowledge.......

 

[Dariusz J.]

Please explain what you mean by a push release. Pushing with the arms?

I'm not saying it's the case here, but there are so many golf gurus out there who uses the cliche, "doing xyz (e.g. early set) will minimise timing factor and make your swing more consistent". If you practice anything enough you're going to get consistent.

Push release is one of three model release types described by Henry Cotton (other two are slap-hinge and crossover types). Open body at impact, late swivel (no crossover in the impact zone), flat/bowed lead wrist and clubhead suare to the swing arc as long as possible between the beggining and the end of the impact zone.
The timing issue is minimized since there is neither vertical (slap-hinge) nor horizontal (crossover) change of the position of the clubface in the impact zone. Clubhead travels square to the swing arc all the zone. A pivot guided impact is a good description, too.
I am not a golf guru - this is just pure common sense.

Cheers

 

[Dariusz J.]

Dariusz,

A steady state, by definition, is just what it implies - all things being in equilibrium. Hence your idea is not really very realistic.

A golf swing is completely different; it is really a transient phenomenon in which there is no equilibrium whatsoever.

Mandrin,

Of course it is not realistic. But it would be easier to uderstand why there must be a release in a human swing motion now, at least for myself. I am very anxious to read your further posts in the topic.

Cheers

 

[jake2]

4) A "negative torque" is not required to prevent the club from releasing. Ever watch a dog chase its own tail? Do you think he's intentionally bending his tail towards his mouth or are the dynamics such that the tail never gets released? Ok maybe that's not the best example but swinging a golf club is the same sort of thing.

Nmgolfer, I like your summary.
Just on this point I'd like to add. The way I look at it, the force used to accelerates the grip end actually provides the torque that prevents the early release.
So yes, there's no need to add "negative" torque by other means.

 

[starretj]

Starretj, as you note, you would have power to spare...so...if you use the more efficient method and yet still input into the system the effort used in the inefficient method you will have a greater clubhead speed. In an analogy to a car, a model with higher efficiency MPG means you can travel a longer distance on the same amount of fuel.

dbl, I don't understand your response. the force is the same, the duration of the force, (or work done) is different in Mandrin's two examples. I don't believe that you can increase your force just because you decide that you want to apply it for a shorter period of time, (considering obviously that we are talking about golf swing durations). If you want to feel efficient and lose more than 25% of your yardage then go ahead. I don't have that luxury.

Jim S.

 

[golfspike]

Push release is one of three model release types described by Henry Cotton (other two are slap-hinge and crossover types). Open body at impact, late swivel (no crossover in the impact zone), flat/bowed lead wrist and clubhead suare to the swing arc as long as possible between the beggining and the end of the impact zone.
The timing issue is minimized since there is neither vertical (slap-hinge) nor horizontal (crossover) change of the position of the clubface in the impact zone. Clubhead travels square to the swing arc all the zone. A pivot guided impact is a good description, too.
I am not a golf guru - this is just pure common sense.

Cheers

Dariusz can you give a some examples of which players use the 3 different types of releases i am not sure but i thought the hingeing factor is a separate entity to the release

 

[jake2]

Then there's this notion of "momentum transfer".... CAREFUL!

When we discuss collisions the notion of momentum transfer most definitely applies. During the deformation and restitution phases of the collision the clubhead is most definitely "giving-up" (transfering) some of its momentum to the ball. But when the clubhead speeds up (during the release) while the hands slow down the hands are not necessarily imparting their momentum to the clubhead. Infact it could be the exact opposite happening. Lets try changing our thinking. Martin Luther King Jr. once said:
..."In a real sense all life is inter-related. All persons are caught in an inescapable network of mutuality, tied in a single garment of destiny. Whatever affects one directly affects all indirectly"...

Said another way and de-anthropormophized we can say: there is an unavoidable Push-Pull acting between all interconnect things. The sun pulls on earth but in turn the earth pulls slightly on the sun. Centripetal / Centrifugal. Action reaction.

What what causes hands to slow is an inablity of the human motor to generate the required force. The required force (to the keep the the hands moving fast) as the club releases, begins to increase. The club is pushing back back on the hands.

Now, I'm not saying that's it always always the case... Some golfers foolishly follow their instuctors' advice and intentionally try to slow their hands. I'm saying the dynamics are such that hand slowing can/does occur and that is does not mean momentum is being transfered in the convention (impact) sense. It simply means there's not enough horsepower available to keep them moving at the same speed. The cg of the club has moved away the center of rotation and therefore inertia has increased... more torque is needed... more horespower.

You have a good point. This certainly is not the same momentum transfer as in an impact.

Here's one example how the term is quite commonly being used though:
"Transfer of momentum in reference to the study of Kinesiology
commonly refers to energy transfer between individual body segments in
order to execute an efficient movement - with one segment decelerating
while the next one accelerates."

Is there any real momentum transfer or is the term used totally incorrectly?

Other thought on hands do not have to slow down. If the body generated torque that forces the grip ahead is large enough to resist the increased inertia but remains constant while the release happens, the acceleration of the hands is still going to decrease, it just doesn't go negative.

 

[jake2]

Dariusz can you give a some examples of which players use the 3 different types of releases i am not sure but i thought the hingeing factor is a separate entity to the release

This slap-hinge release might have more to do with wrists action than with tgm hinge action concept. I'm just guessing.

 

[Dariusz J.]

Gents, it's a bit off-topic to speak in this thread about the 3 Cotton's release types. I will open a new thread where I try to desribe them in my own words. Here I would like to hear only about the mechanism of the release, because it's more important than Cotton's classification.

Cheers