How to maximize wrist lag and av

How to Maximise Wrist Lag and Avoid Casting

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In this short review paper, I will be discussing the important issue of how a golfer can maximise wrist lag during the downswing and how he can avoid casting.

To start, let me define the term "lag". What does it mean when one states that a golfer is lagging his club during the downswing? "Lag" is the term used to describe the phenomenon where the clubhead is lagging behind the hands throughout the downswing. Consider the following schematic diagram depicting the movement of the hands and club during a full golf swing [1].

Clubshaft and clubhead movement during the downswing and followthrough

This diagram depicts the movement of the hands and club during the full golf swing of a low handicap golfer. The inner circle traces the movement of the hands/grip throughout the downswing/followthrough, the straight line represents the clubshaft and the rectangular box-end represents the clubhead. It can be seen that the hands lead the clubhead throughout the downswing, and that the clubhead only passes the hands after impact (after ~ 6 o'clock position). At impact, the clubshaft should have a slightly forward lean as the hands should be slightly ahead of the clubhead at impact. A good golfer will ensure that he lags the club throughout the entire downswing and he will never let the clubhead flip past the hands before impact. This explanation should give a beginner golfer an understanding of what is meant by the term "lag" from a qualitative perspective. However, a beginner golfer should also appreciate that lag has a quantitative aspect. From a quantitative perspective, one should assess the amount/degree that the clubhead lags behind the hands at different points in the downswing. If one looks at the above diagram, one can discern that the degree of lag is greatest at the start of the downswing, that it lessens slightly during the mid-phase of the downswing, and that it lessens markedly during the late phase of the downswing. The term "release" is commonly used to describe the marked decrease in lag that occurs in the late downswing (when the clubhead starts to catch-up to the hands), and I will also be discussing the release phenomenon in this paper.

What is meant by the term "maximising wrist lag"? Maximising wrist lag refers to the situation where the golfer attempts to retain the greatest degree of lag for the longest period of time during the early/mid downswing. Consider the magnitude of Ben Hogan's downswing wrist lag.

Ben Hogan's wrist lag during the downswing

The lag angle (also called the release angle) is the angle between the clubshaft and the left forearm and it is a measure of the magnitude of wrist lag. In image 1 (end-backswing position), one can see that Ben Hogan had very flexible wrists that enabled him to establish a large degree of lag at the beginning of the downswing - his lag angle is <90 degrees. Most amateur golfers will not be able to achieve a magnitude of lag that large, and they should attempt to achieve a lag angle of at least 90 degrees at the end-backswing position. The narrower the lag angle at the beginning of the downswing, the more lag that a golfer will have at any measuring point during the downswing. Most importantly, a good golfer often has the capacity to retain that 90 degree lag angle for as long as possible during the downswing. Note that Ben Hogan has the amazing ability to retain a 90 degree lag until very late in the mid-downswing - until his hands are well below waist level (image 4). The term "maximising wrist lag" refers to the situation whereby a golfer attempts to maintain the maximum amount of wrist lag in the early/mid downswing - from image 1 to image 4 in the above sequence - because maximising wrist lag maximizes clubhead speed at impact.

Most amateur golfers cannot retain their maximum degree of attainable lag in the early/mid downswing, and they start to lose their maximum degree of attainable lag relatively early in the downswing. Consider a comparison between an amateur golfer's swing and Ben Hogan's swing.

Comparison of the degree of lag between ClubCaster (amateur golfer) and Ben Hogan.

ClubCaster is the chosen internet-name that an amateur golfer, who is fascinated by the subject of "what causes casting", uses at his personal website. Casting in the term used to describe the phenomenon whereby the maximum degree of lag angle is lost in the early downswing - as if the golfer is intentionally, or uninterntionally, casting the club like a flyfisherman casting his fishpole when flyfishing.

Clubcaster is so interested in the cause of casting that he established a website to study the subject (called "ClubCaster's Golf Swing Improvement Site" dedicated to finding a cure for casting [2]), and he periodically updates his website by plotting changes in his degree of casting with the passage of time. The top half of the above photo compares ClubCaster's downswing (from July 2006), at comparable points in the downswing, to Ben Hogan's downswing. Note that Clubcaster managed to obtain a 90 degree lag angle at the end-backswing, which is very good for an amateur golfer. Note that ClubCaster starts to lose his maximum degree of lag angle very early in the downswing (image 3), and that he has lost his 90 degree lag angle by the time his hands reach below waist level (image 4) - while Ben Hogan can still retain a 90 degree angle at that same point in the downswing (image 4). What enables a good golfer, like Ben Hogan, to retain wrist lag and avoid casting? That's the subject-topic for the remainder of this paper.

How to maximise wrist lag and how to retain the maximum attainable wrist lag during the downswing

I have perused >30 golf instructional books, and many of them advise a golfer to maximise wrist lag and to also retain that wrist lag for the longest possible time during the downswing. Interestingly, and significantly, although the book authors uniformly make this recommendation, they generally do not explain how to achieve this goal. The phrase "retain wrist lag" or "maintain wrist lag" is commonly used, but how is that goal achieved. Some book authors imply that retaining wrist lag is an active phenomenon, but is that true? Does a golfer need to actively retain his maximum-attainable wrist lag by actively using his wrists in some fashion, or is the phenomenon of wrist lag a passive phenomenon that is primarily due to other factors? Insight into this problem is gained by examining the writings of book authors who seriously address this complex issue.

In their book [3], the SLAP authors, who computer-analysed the swings of hundreds of professional golfers, stated the following with respect to lag-:

"The Magical Release Angle. A well-known yet somewhat sophisticated term in teaching circles is "retaining the release angle". This expression refers to the angle created by the left arm and the clubshaft during the downswing. It plays a critical role in your ability to generate clubhead speed and greater distance. The basic rule is this: the more acute the angle, and the longer you can retain the angle during the downswing, the further you will hit the ball. -------- Good mechanics is the only way to produce a model release angle. It must be allowed to happen, and no amount of effort or determination can force it to occur. ----- the angle narrows primarily because of the way the lower body and right side work as the move towards the target gets underway."

The SLAP authors do not elaborate further on this issue in their book, and they do not fully explore the causal connection between "how the lower body and right side works" and a golfer's ability to retain the release angle.

The best best golf instructional books (that I have read) dealing with the issue of lag are by Mike Hebron [4] and Bobby Clampett [5].

In his book [4], Mike Hebron states-:

"Retain the angle - retain the angle - some books and golf teachers will loudly suggest. During the front swing, they want golfers not to change the angle or position that the hands and wrists fall into at the top of the backswing until the impact area. In my view, when you do nothing consciously with the hands, arms and club in the front swing, this all important move of retaining the angle is automatically accomplished. It has to be. The only time the angle will break down is when the golfer tries to do something with the swing besides moving forward with the lower inside."

In other words, Mike Hebron is suggesting that a golfer doesn't hold the angle by some active wrist/hand manipulations, and he recommends that the golfer shouldn't do anything consciously with the hands/arms/club. The golfer should only move the lower inside forward. What does he mean by this statement? Consider the following diagram from his book.

The Inside Moves First - Mike Hebron [4]

In his book, Mike Hebron has the following statement accompanying the above diagram-: "When the hands and arms do nothing, and are moved by the inside, the ANGLE is retained". What is the inside? What he is basically saying is that the shift-rotation of the lower body to the left at the start of the downswing (which causes the lower-mid torso to rotate around to the left), will move the hands down to waist level while retaining the wrist lag angle. How is the wrist lag retained during this movement of the lower body? Mike Hebron states that it will happen automatically, but I believe that it will only happen automatically if a golfer allows the left arm and right arm to move as a single unit - in response to the movement of the lower torso. What represents a single unit? The following photograph will help explain that "single unit" concept.

Ben Hogan - adapted from reference number [6]

I have deliberately colored in yellow Hogan's left and right arm. Note how the right elbow is still bent at a right angle - as it was at the end-backswing position. As Ben Hogan rotates his lower body towards the target, the straight left arm + bent right arm act as a single unitary structure and they are passively pulled down towards waist level as a single unit. In other words, Ben Hogan does nothing actively with his hands/arms/club - he simply allows them to respond reactively/passively to the rotational movement of the lower body. The following swing video will demonstrate Ben Hogan performing this downswing move in "real life".

Ben Hogan's downswing initiating move - http://www.youtube.com/watch?v=QL_6M_xZvq0

When watching the video, pay strict attention to the distance between Ben Hogan's hands and right shoulder as he repeatedly performs the lower torso rotational movement - note that this distance remains constant during this maneuver. This fact is very important because it demonstrates that the right shoulder must be moving forward at the same rate of speed as the hands. This fact also proves that Ben Hogan is not moving his arms/hands independently away from his body. The arms/hands are passive and are moved downwards and forwards by the rotation of the torso - the lower-mid torso moves first, and the upper torso immediately follows. Some TGMers (golfers who study Homer Kelly's book "The Golfing Machine") refer to the yellow-colored area as the power package assembly. They state that a golfer should assemble the power package assembly at the top of the backswing, and then drive the power package assembly (as a single unitary structure) down towards the ball by performing the downswing pivot movement (as demonstrated by Hogan). In other words, the swing is forward-driven by the pivoting motion of the body, but directed by the hands. What do I mean by the statement "directed by the hands"? If a golfer has "educated" hands (golf-experienced hands) then he has learnt to intentionally drive his hands, from their end-backswing position, towards the ball along the shortest arced-path. However, the hands do not actively drive down towards the ball as a result of some active force within the hands/arms. The force is supplied by the rotational movement of the torso, and the hands only direct the show - only direct the movement of the hands along the appropriate hand-path down towards the ball. It can be said that he hands direct the path of the swing, while the body (torso) powers the swing.

The most instructive information that I have found on wrist lag is found in Bobby Clampett's book [5].

Bobby Clampett has an unorthodox approach to golf instruction in the sense that he doesn't focus on body positions, but he instead focuses on dynamics. The fourth dynamic in his book is "Lag and Body Pivot" which he refers to as the golf swing's workhorse, and he devotes an entire chapter to the subject. He states that-: "lag not only belongs to the downswing of your motion, it is the downswing's number-one priority, concern, and goal, until youv'e swung well past the both-arms-straight, followthrough position". In other words, he is not only concerned about the initiating downswing body motion that maximises lag, he also discusses the other body motions that are necessary to ensure that lag is maintained throughout the entire downswing until, and beyond, impact.

Bobby Clampett agrees with Mike Hebron that the downswing pivot motion, which lags the power assembly package, is critically important to a good swing and he states-: "If the power that you lag into impact is your precious cargo, the pivot is the transportation vehicle that carries the goods through the impact zone. That is why we call the pivot the golf swing's workhorse". However, Bobby Clampett is not only focused on how best to maximise lag in the early downswing - he is even more focused on how best to maintain the lag all the way through impact. He writes-: "While your goal may be to develop your dynamics to their fullest - meaning, to create as much lag in your downswing as you are individually capable of creating, the number-one goal that you must achieve now and not later is to create, sustain, and maintain your lag through the impact zone."

What additional advice does Bobby Clampett offer that allows a golfer to maintain lag through the impact zone?

First of all, he believes that being focused on the ball is a major problem for beginner golfers and he thinks that many beginner golfers, who are too ball-focused, swing too hard, and therefore over-accelerate into the ball. He states-: "The main reason people swing too hard, and throw their lag away as if it were a worthless scrap of paper wrapping an energy bar (rather than the energy of the golf swing itself), is that, in their anxious effort to hit the ball so hard, they become overly fixated on the ball. Such ball-fixation leads to premature uncocking of the wrists. This clubhead throwaway, again, dumps the club behind the ball, instead of driving its forward swing bottom four to five inches in front of the ball." What Bobby Clampett is saying is that a major cause of casting is hitting hard from the top of the swing with the hands, which often causes a beginner golfer to actively unhinge the right wrist and actively throw the club forward into a premature release. Bobby Clampett states-: "Picture your swing, with the lag angle increasing, as the club starts into the downswing. Your fingers are firm on the club, but your wrists are free and relaxed. Your hips initiate the downswing with a blend of a forward shift towards the target and a shift, which helps to sustain this increased angle as long as you can on the downswing. In other words, you never let go - never let the left wrist begin to uncock even the smallest amount, because once it begins to uncock it keeps going, throwing lag away with it". Bobby Clampett is bringing up an important point that is needed to maintain lag - relaxed wrists that allow the clubshaft to lag behind the hands. Many beginner golfers have too much tension in their wrists, which often causes premature release of the club (club throwaway) - and as Bobby Clampett points out, once the left wrist begins to prematurely uncock, there is no going back.

What I like about Bobby Clampett's thinking on "maintaining lag" is that he emphazises the important point that one shouldn't 'quit on the shot'. Many beginner golfers learn to start the downswing correctly with a lower body move, that initiates the downswing pivot action, but they don't continue to drive their downswing through the impact zone. To drive the swing through the impact zone, a golfer must continue to actively turn the torso, especially the right shoulder, through the late downswing, through the impact zone, and into the followthrough. The right side of the body (right mid-upper torso, right shoulder) is an essential part of the downswing pivot action, and the right side must keep up with the left side as one drives the downswing pivot motion through the impact zone. Bobby Clampett writes-: "As you approach the impact zone, you simply "ride" your pivot motion through to the end of the swing, without making any conscious adjustment for hitting the ball. It's as if you were to visualize the ball as a soap bubble, and your fully loaded and lagged club swings right through it --- One of the reasons all golfer struggle with sutaining the lag is that they haven't trained their workhorse, the pivot, to deliver their lag forward enough through the impact zone". I think that Bobby Clampett is correctly making a critically important point - one must drive the body and subsequently the arms/clubshaft, through, and beyond the impact zone, to ensure that one has a forward-leaning clubshaft at impact.

In summary, Bobby Clampett emphasizes two major factors that are needed to maintain lag through the impact zone - free and relaxed wrists (passive wrists) and a downswing pivot action that delivers the lag forward enough through the impact zone.

The following swing video may change your thinking - if you are personally sceptical of the validity of Bobby Clampett's advice.

The following swing video is of the PingMan machine, the type of mechanical machine used by golf club manufacturers to test their golf clubs.

PingMan machine video - http://homepage.mac.com/brianmanzella/.Movies/PINGMAN.mov (long download time). A mp4 file, of the same PingMan machine swing video, has a shorter download time, and it can be dowloaded from this url address - http://www.mediafire.com/?4tj0bn02yj1

Note that the PingMan machine has a single central arm that is actively rotated by some motorised mechanism at the central hinge point. The club is attached to the far end of the central arm at a passive joint. No active movements occur at this peripheral joint. During the downswing, the central arm seemingly swings at a constant rate of speed, and the rate of speed is presumably user-controllable. The PingMan machine stops at the end of the backswing and allows the clubshaft to settle into an approximately 90 degree lag angle. What happens to this lag angle during the downswing? Can the PingMan machine retain this lag angle, and when does the release occur? Because it is impossible to answer those questions when looking at the swing video run at normal speeds, I ran the swing video ultra-slowly, advancing the video frame-by-frame, and then captured a number of downswing images.

Lag and release action of the PingMan machine

Note that the PingMan machine has the ability to retain a 90 degree lag angle until the hands (peripheral hinge joint) reaches a waist-high level, and that it can maintain some lag through impact (hands are ahead of the clubhead at impact) - similar to the lag/release pattern of a good golfer. What factors are responsible for this phenomenon? I believe that the major factor responsible for the PingMan machine's ability to maintain lag until impact is the fact that the rate of speed of movement of the central arm must be sufficiently fast to allow the peripheral hinge joint to outrace the clubhead. The clubhead is presumably gaining momentum during the first half of the downswing and this force of momentum is presumably augmented by the force of gravity when the clubshaft passes through the vertical position. The clubhead's force of momentum allows it to nearly catch-up to the hands (peripheral hinge joint) by impact. One could imagine a situation where the clubhead could actually pass the hands prior to impact (flip past the hands) - if the hands (peripheral hinge joint) slowed down during the latter part of the downswing. However, the PingMan machine maintains a constant, and fast, rate of speed of the hands (peripheral hinge joint) throughout the entire downswing and followthrough - and this allows lag to be maintained through the impact zone. Another important point to note is that the PingMan machine can retain a 90 degree lag angle throughout the first half of the downswing - even though it has passive hands, which cannot actively hold (actively retain) a maximised lag angle. This important fact tangentially suggests that a golfer doesn't need to actively use the wrists/hands to 'hold the release' in the early downswing. All that is required is relaxed wrists (passive wrists) and a reasonably fast left arm downswing, that is not jerky-in-motion, but smooth-in-motion. A beginner golfer needs to understand what is meant by the term "passive wrists". "Passive wrists" are not loose and limp wrists that have excessive floppiness. "Passive wrists" are simply "quiet" wrists that are passively reactive to the momentum of the club in the downswing, and passive wrist allow the release to occur without any interference. In "real life", a golfer shouldn't even have to consciously think of his wrists/hands during the downswing, and he should simply think of executing a downswing pivot movement that causes the arms/hands to move fast and smoothly down to, and through, the impact zone.

Bobby Clampett also emphasizes the need for a fast downswing left arm action in his book [5]. He states-: "Another way to increase lag in your swing is to improve your tempo in the transition of the backswing to the downswing. If your tempo is too slow - that's right, too slow - you will not create enough momentum in the swing to effectively create lag on the downswing." I think that Bobby Clampett is correct - the left arm must move sufficiently fast in the early downswing to maximise lag. To move the left arm fast, one must move the entire power package assembly fast, and that requires a fast downswing pivot action. Secondly, one needs to continue to actively move the left arm (and hands) fast through the remainder of the downswing - in order to ensure that some lag is maintained through the impact zone - and the right side of the body (right upper torso/right shoulder) is primarily responsible for continuing to drive the hands at a fast rate of speed during the latter half of the downswing. A beginner golfer needs to understand that he cannot apply a body-generated downswing force at the beginning of the downswing and then 'quit on the shot' through the remainder of the downswing. He should think of maintaining a relatively constant rate of speed of his left arm (hands) throughout the entire downswing, which means that he should think of turning the torso actively, and continuously, throughout the entire downswing, and into the followthrough.

Here is a link to a swing video of a left-armed golfer hitting the ball 240 yards - even though he doesn't have a right hand to supply extra power, or help enact a release.

http://www.youtube.com/watch?v=uUTk7m5PozQ&mode=related&search=

Look how fast he turns his torso, and how fast he whips his left arm throughout the entire downswing. Although there is a slight delay at the start of the downswing before his left arm gains high velocity, it doesn't take long for the left arm to be moving very fast in the early downswing. Also, note that his left arm movement is very smooth throughout the downswing and early followthrough, and that he can both retain lag and execute a perfectly natural release action - without any help from a right arm/hand.

I used the term "constant velocity" to refer to movement of the arms/hands throughout the entire downswing. I actually think that it is much better for a golfer to think of a constant force, rather than constant velocity, and a golfer should think of that constant force causing the hands to move at a low rate of steadily increasing acceleration throughout the downswing, so that the hands reach maximum speed at, or near, impact. If the hands do not accelerate steadily throughout the downswing, even though the rate of acceleration (change in hand velocity per unit time) is very low, then there is less likelihood of a golfer being able to successfully maintain lag throughout the entire downswing. How is that force applied to the clubshaft's grip via the hands? Some golfers think of the golf swing as being a "left arm pulling" action, while other golfers think of a "right arm pushing" action. I personally think that the right side must push, and the left arm must pull, to exactly the same degree - because the two push-pull forces have to compliment each other perfectly to ensure the smooth movement of the hands throughout the downswing.

George Hibbard discusses how the right side applies force to the hands in his golf instructional book [7]. I have adapted, and modified, a photograph from his book to illustrate this point.

Adapted, and modified - from reference number [7]

George Hibbard has drawn an "X" on the base of the right thumb palm and the back of the base of the left thumb to show how pressure is applied by the right side to the left hand (I have colored that "X" area in yellow to emphasize that point). If one has a perfectly neutral grip, the lifeline of the right palm nestles over the back of the left thumb, and the conjoined grip allows a golfer to transmit pressure from the right side (right upper torso pushing down through the right upper limb, which partially straightens in the late downswing) to the left hand, and consequently to the grip end of the club. During the downswing, while the left hand is pulling the grip down to the ball, so that the butt end of the grip moves straight down in the direction of the ball, the right side is applying pushing-power at the same time. In this push-pull power arrangement, the push-power has to perfectly match the pull-power, so that the hands (and grip end of the club) moves smoothly down to the ball at a low rate of steadily increasing acceleration. If the push-pull arrangement is not perfectly balanced, then the hand-swing can become jerky, which will markedly decrease the likelihood of the golfer being able to sustain a constant amount of lag on the club throughout the downswing. How does a golfer know whether he is applying a constant lag force on the club?

An experienced golfer, who has a well-developed sense of hand proprioception, should be able to sense lag pressure at the trigger finger (right index finger). When a golfer adopts his right hand grip, he should slightly seperate the right index finger from the middle finger, and he should use a light pincer-grip between the right index finger and right thumb to hold the grip. Note that I have colored an area over the first joint area of the right index finger and the adjacent areas of the first and second phalanxes of the right index finger, and that red-colored area is where lag pressure is felt during the downswing. At the top of the backswing, a proprioceptively-sensitive golfer should be able to sense the weight of the club applying pressure at that point. During the downswing, the golfer must maintain that same sense of lag pressure throughout the entire downswing. If a golfer over-accelerates the hands in the early downswing and then decelerates the hands in the later downswing, casting (clubhead throwaway) will occur and the sense of lag pressure at the lag pressure point will be lost. A golfer must strive to maintain a constant sense of lag pressure at the lag pressure point throughout the downswing, which is a good indicator-sign that he is sustaining a low rate of steadily increasing hand acceleration throughout the entire downswing.

Some golfers use lag pressure as the primary means of controlling/supervising the speed of movement of the hands during the downswing - whether chipping, pitching or executing a full golf swing. They do not attempt to achieve a constant hand downswing force, or constant hand velocity, but they use use lag pressure to modulate the speed of movement of the hands during the downswing so that there is a low rate of steady hand acceleration throughout the downswing. They obviously have "educated hands"!

Finally, there is one additional swing thought that can help a beginner golfer maintain lag through impact - the mental idea of hitting through the ball, rather than hitting at the ball.

See the following Shawn Clements swing video on hitting through the ball

http://www.youtube.com/watch?v=wBFLHjDA7rw&mode=related&search

A golfer's mental focus must be on the target, and not the ball, and Shawn Clements' two-ball drill (seven minutes into his video) may help a beginner golfer achieve that goal.

Conclusion:

From a beginner golfer's perspective, I think that he should focus on two major elements when attempting to maximise wrist lag and avoid casting - i) ensure that the wrists are very relaxed and passive; ii) and ensure that he has a very good downswing pivot action that drives the left arm (actually the entire left/right arm power package assembly) and hands fast and smoothly all the way through the impact zone without quitting on the shot.

To avoid casting, a beginner golfer should avoid - i) increased wrist tension (stiff wrists); ii) hitting from the top with the right hand; iii) having a jerky downswing move with most of the energy expended at the start of the downswing; iv) having too slow a downswing; v) trying to hold the release by means of some active wrist/hand mechanism; vi) trying to 'time' the left wrist uncocking/right wrist unhinging release action (which should occur automatically/naturally without any need for conscious thought) during the downswing.

Jeff Mann.

September 2007.

Addendum on the physics of the release action:

How does the release occur if the speed of hand movement during the downswing is constant (like the PingMan machine) or near-constant (like a good golfer)? There are many different explanatory opinions on this matter, and the most satisfactory explanatory opinion that I have personally read is as follows-:

My explanation comes from a mechanical engineer’s description of angular velocity developing because the line of action force is NOT at the centre of gravity (COG) of the club.

Imagine the following situation. Imagine a golfer’s left arm (or PingMan’s central arm) moving at constant velocity throughout the ENTIRE downswing, which means that the hands must also move at a constant velocity. However, the direction of movement of the hands is not a straight line path, but a more circular path (from the end-backswing position to the impact position). The grip end of the club must move exactly as the hands move – because the grip is within the hands. However, the clubhead does not have to do so, because the COG of the club is somewhere close to the end of the shaft, near the clubhead, and it is possible for the clubhead end of the club to lag behind the hands (or move in front of the hands if the momentum of the COG of the club causes the clubhead to move faster than the hands, and causes the clubhead to overtake the hands). Now let’s start at the end-backswing position. As the hands start moving at a certain (constant) speed along a directional path (which is essentially the near-circular downswing hand path) a line of action (force) is applied to the grip end of the club. That line of action force is also applied to the clubshaft/clubhead and most of the line of action force may be along the length of the club. However, it is not necessarily perfectly in line with the COG of the club, so some of the line of action force working on the clubshaft causes the clubshaft to develop a small degree of angular velocity, which causes the clubshaft to rotate forward relative to the hands (which causes the peripheral end of the clubshaft to rotate anti-clockwise relative to the grip end of the clubshaft – as seen from the front). At the start of the dowswing, the amount of line of action force that produces angular velocity is small, so the clubshaft remains at 90 degrees to the left arm. However, as the downswing evolves, the amount of angular velocity increases progressively and eventually it must result in club release and eventually it must allow the clubhead to nearly catch up to the hands by impact. To develop this explanation to its full extent, mathematicians woul;d have to produce a mathematical model that would demonstrate the change in angular velocity over time, which may depend on many variables such as i) speed of hand movement during the downswing, ii) constantly changing degree of circularity of the hand path (which represents the fractional change in direction of a straight line path per unit meaasure of time); iii) distance of the COG from the grip end of the club; iv) weight of the clubhead and peripheral end of the club relative to weight of the grip end of the club (? may be equivalent to the magnitude of the mass of the club’s COG).

I don’t have the expertise to solve this problem mathematically, but I intuitively suspect that the fundamental cause of the release is the fact that the line of action of the force driving the club is NOT at the COG of the club, and therefore the club has to rotate – because some of the line of action force produces clubshaft angular velocity.

Here is a link to a mathematical explanation of the release phenomenon - http://nmgolfscience.tripod.com/release.htm

Commentary, criticism and controversy:

Insightful comments from readers will be included in this section.

References:

1. Steven Nesbit. A three dimensional kinematic and kinetic study of the golf swing. Journal of Science and Sports Medicine. Vol. 4 Issue 4. Page 499-519.

http://www.jssm.org/vol4/n4/17/v4n4-17text.php

2. ClubCaster's Golf Swing Improvement Site.

http://clubcaster.home.comcast.net/index.html

3. Swing Like a Pro. Ralph Mann and Fred Griffin.

4. See And Feel The Inside Move The Outside. Mike Hebron.

5. The Impact Zone. Bobby Clampett.

6. The Fundamentals of Hogan. David Leadbetter.

7. Golfs' Critical Details. George Hibbard.