The Golf Swing and Traditional Dogma

The Golf Swing and Traditional Dogma

I ask every first-time student to do this “drill”

  1. Get into your address position and look to see which shoulder is lower
  2. Get into your impact position and look to see which shoulder is lower
  3. Get into your top of backswing position and look to see which shoulder is lower

And then I ask them what sense it makes for the shoulders (and, in fact, the entire torso) to flip directions.

One person has said “maybe because I raise my arms”? That needs no reply.

Another said “because we must stretch muscles that we wish to contract in the downswing”. Now that response did, indeed, have some validity. However, the muscles that get stretched UPWARDS (as the trail side of the torso rises), mainly the trail-side external obliques, will then contract in a downward direction, rather than a towards-target direction.

And this one I get all the time, “It’s obvious because we rotate around a forward tilted spine and must maintain the spine at its inclination during the downswing”.

Why do we HAVE to incline the spine in the first place? There is only one reason, not a particularly scientific one, at that. Let’s look at a bit of golf history to understand.

It all began (probably) with golf clubs being rather short. Why is that though? One of the theories of who the first golfers were is that they were shepherds in Scotland who knocked pebbles into small holes in the ground with their crooks – which for experienced shepherds were only of a length to reach the ground after being hooked around the forearm (http://theshepherdscrook.net/ and http://www.the-best-golf-tips.com/History-of-Golf-Clubs.html)

So then golfers intuitively bent forward because the clubs were short (or because they were tall!). Do you think Mary Queen of Scots or Old Tom Morris had a fixation about “spine angles”?

.

[To digress: the only things we MUST DO in a golf swing are (Other than have good speed):

  1. Arrive at the ball from an inside path
  2. Connect the ball at its near, trail-side quadrant.

Everything else has been added on by famous players and teachers, subjectively and piecemeal. And, in recent years, by some researchers who do not know whether their theoretical ideas can actually work in practice because they have not taught tons of golfers. There are too many “must make” movements that have been added on in recent years and when put together they can be useless at best and harmful at worst.]

So now we have created generations of golfers with a forward spinal tilt at address, and that one factor itself can have both performance and injury issues.

THE SCIENTIFIC FACTS:

  1. The forward spinal tilt at address is accompanied (by tradition) by a torso position at the top which may be visually observed as the lead side (shoulder, hip, knee) being lower than the trail side at the top of the backswing. It involves a combination of forward flexion, side-bend and rotation. However, from that top of backswing position, the downswing is expected to produce the sequence of pelvis-before-thorax (or shoulder, if you prefer) HORIZONTAL rotation. Now the muscles that can provide horizontal rotation of the pelvis are the gluteal muscles, but they require the pelvis to be level (not lead side down and trail side up) to act effectively. If, instead, a golfer uses the external obliques at the front of the torso, along with the trail side pectoralis major and latissimus dorsi to start the downswing (much easier), one gets an over-the-top movement as these muscles contract downwards and forward. BRIEFLY, THEN, the TYPICAL TOP OF BACKSWING POSITION cannot be easily undone by THE MUSCLES WE HAVE.
  1. Equally importantly, the brain and spinal cord were really not designed for golf, but rather for hunter-gatherers whose main activities were to run (lower limbs) and gather fruit/eat (upper limbs). All the parts of the central nervous system (ie brain and spinal cord) focus their resources on controlling muscles of the extremities (arms and legs), while having little input into torso movements. (a really detailed article here: https://www.minimalistgolfswing.com/the-brain-and-the-mgs/). Thus, while motor control theory tells us that the brain is very capable of coordinating many movements within a well-learned skill, it will probably simply try to “do its best” which may not be adequate for the sophisticated pelvis-before-thorax movement a golf downswing requires, based on its complex, three dimensional, top of backswing position. In short, THE TYPICAL TOP OF BACKSWING POSITION cannot be undone in perfect sequence during the ever-changing situation in golf play, by the HUMAN CENTRAL NERVOUS SYSTEM.

PERFORMANCE ISSUES (one can blame all of the following on the uneven lead and trail sides of the top of the backswing resulting from a forward spinal tilt at address)

  1. Over the top shots
  2. Too limited a space between the trail shoulder and wrist, making straightening of the trail elbow and wrist at the correct time and in the correct directions inconsistent. This in turn results in the dreaded two-way, unpredictable miss.

INJURY ISSUES (once again, one can blame all of the following on the uneven lead and trail sides of the top of the backswing resulting from a forward spinal tilt at address)

1.     One research paper (Comparison of spine motion in elite golfers with and without low back pain) found a significantly greater forward lumbar tilt of address in their participants with low back pain compared to those without (and, incidentally, those with low back pain also had significantly greater lead side lateral flexion – side bend – at the top of the backswing!). And while one could argue that they had that forward tilt to mitigate the pain, it is far more likely they got the pain from constantly holding the spine, especially the lumbar spine, in forward tilt, especially during the great speed of the downswing.

2.     The crunch factor has been associated with low back pain, and increases greatly when the trail side of the torso must be dropped down from a greater height during the downswing. [crunch factor, in simple terms, is the combination of trail side side-bend and torso rotation speed, during the downswing].

So, what should a golfer do instead? I have developed a golf swing in which a golfer has as upright a posture as possible (given the historically short clubs – am working with Cobra-Puma’s one length clubs for better solutions). Then the backswing is an arms-only movement which maintains the lead shoulder higher from address to backswing, so the arm-club system has a fixed-height for its hub. Then, finally, for the speed, the “engine” is of course the torso. It is harnessed very minimally and very late to move the arms rapidly through impact, based on the principal of “proximal stillness for distal speed”.

Why should anyone trust this information? It is based on either the text-books in the subjects of anatomy, motor control and biomechanics and/or all golf swing research ever conducted and/or my own 27 years of research on the golf swing, including for my recently completed doctoral dissertation.

 

So, if you’d like to know how to get into positions and make movements which will improve performance and reduce some injury risk factors, get in touch!

 

For in-person and online lessons contact me at: www.YourGolfGuru.com

 

For video lessons: www.mgs.golf

 

For inquiries on hosting/marketing certification courses for golf instructors or health care professionals (including all the basic sciences that are a must for everyone in the business of golf): www.YourGolfGuru.com

Kiran Kanwar, Ph.D., LPGA Master Golf Instructor.

The two-way miss that the Pros dread.

A brilliant statement by Bryson DeChambeau’s lifelong golf coach Mike Schy was the basis for this article. When asked what he thinks is the movement that causes the most inconsistency among golfers, he made a completely instinctive, off-the-cuff statement that only someone with his years of being a keen observer of all skill levels of golfers could have, “Professionals are the greatest steerers of the golf ball on the planet – and they were always told ‘don’t steer’. Amateurs try to steer but are not ready to, because they don’t have the strength or ability yet. So they’re told ‘try to trust, try to trust’ and yet they’re always trying to steer. The pro golfer, when he’s ‘on’ is the epitome of ‘steering’. When he goes away from that, when he’s trying to trust timing, that’s when the ball goes everywhere.” The “steer”, incidentally, is considered by many to be a last-minute effort by the hands to try to square up the face at impact.

So according to Schy, the best thing an elite golfer can do is let the ‘steer’ happen. He probably said that because a really skilled golfer’s subconscious mind knows what to try to do in the split second before impact to save a shot. This is a well-known concept from the motor control world. Motor control scientists are those who try to figure out how the brain tries to organize human movement. A pioneer in the field of motor control, Nikolai Bernstein, has said that feedback on the sensory effects of a movement plays a substantial role in the control of complex movements. Of course in the golf swing when the feedback from a downswing about to go awry is really late, only those with many years and repetitions of the movement can even attempt to do anything about that feedback. So it may be seen why only professional and other skilled golfers might get late feedback of how their downswing is going and still be able to attempt a last-minute change – a movement which could very well be termed “steering”!

However, there is one reason why the professional probably begins to doubt the seemingly effective steering. And that is his unexpected two-way miss. In a video on some recently-explored swing-change ideas (https://www.youtube.com/watch?v=1aeTZTMSZcw), DeChambeau said, “I gotta change something. I can’t go out and win a tournament and go out and miss the cut the next week. I need to be way more repeatable”. He then said he tried something and found that if, like Jordan Spieth, he had his lead elbow pointing towards target, he could not possibly hit it left, and he was able to achieve that position by “going to the max” of lead (his left) shoulder internal rotation (upper arm rotated inwards towards the torso). This was part of a conversation Bryson had with golf instructor Chris Como, and they spoke in detail about how getting a body part into an “end-range of motion” can create a lock to prevent a body segment from overshooting a good position at impact.

Getting the lead shoulder into an end-range of internal rotation is not always possible, as it requires specific positions of the trail arm and torso to happen simultaneously. Moreover, an end-range of motion in a joint is a risk factor for injury. Additionally, there are much simpler ‘locks’ to prevent undesirable movements than those created by interfering with the rather complex situation of the two hands joined together at the club’s grip. Finally, probably the main cause of the two-way miss from misdirected steering, which many professionals experience and really do not know the cause of (see page 72 of https://en.calameo.com/read/004756792786810f37cc8), is the position of the trail shoulder, elbow and wrist when the club is parallel to the ground during the downswing (see picture below).

Because the professionals make an extremely rapid pelvic rotation towards target, the shoulders, which are strongly coupled with the pelvis’ rotation among professionals (we know this from research), rotate open too. This serves to position the trail shoulder into protraction (forward bend) and internal rotation (see picture below). And that is a problem for the trail elbow, as it is designed to most easily extend (straighten out) when the shoulder is slightly externally rotated. So, trail elbow extension becomes an awkward movement, leaving the wrists and hands to “fend for themselves”. And THAT is the cause of steer, with the golfer scrambling to do something very late in the downswing to square up the hands, and not always succeeding. It may thus actually be a case of an effective steer BEING timing dependent rather than the opposite of it, all predicated upon how easily the trail elbow can straighten. The inability to steer effectively is exacerbated under pressure, when arm and forearm muscles tense up.

Only one swing – The Minimalist Golf Swing (MGS) – prevents the early protraction and internal rotation of the trail shoulder, and thus positions the trail elbow so that it is straightening while the shoulder is more externally rotated. As the elbow extends more comfortable, the wrists are able to accomplish their downswing roles more efficiently. While not a solution to the problem, the sign that the trail arm is in a better position is when the forearm is not at 90°, or perpendicular, to the torso (picture on the left, below) but rather at about 45° to it (picture on the right), when the shaft is horizontal. Moreover, there are several factors that require to happen to ensure a good trail shoulder position, so that a quick-fix downswing movement would not be adequate to improve the situation. A facsimile of the MGS is therefore the only sure way to prevent a last-minute, timing-dependent steer on a consistent basis.

Ground Reaction and the Golf Swing – What’s All the Fuss About?

Ground Reaction and the Golf Swing – What’s All the Fuss About?

 

Part I of II – forces and moments; center of pressure and center of mass

 

Once upon a time, a gentleman named Isaac Newton, unbeknownst to himself, created a storm in a teacup for golfers around the world. He did that by telling the world (one of three things he told us) that “to every action there is an equal and opposite reaction”. One of the best explanations for this, his Third Law, is in section 3.2 of a paper from Dartmouth University which literally explains Newton’s original writings from his book “Principia” (http://www.dartmouth.edu/~sci14/Sci13/13Day6/13Day6typeset.pdf).

 

It is important to note that a force (“action”) can be applied in any direction, not merely downwards. Any force being applied by an object will have a reaction from the object with which it is in contact. For instance, as a swimmer pushes off a wall, the swimmer exerts a force on the wall and the wall exerts an equal and opposite force on the swimmer. In any calculation, physicists only consider the action that takes place on an “object of interest”. So, as the force on the swimmer is of interest to biomechanists, the reaction from the wall would be factored into calculations, not the swimmer’s effect on the wall!

 

When a person is standing still on the ground, the force exerted by the person on the ground is his/her body weight (the effect of gravity on the body). If there was no other force involved, then the person would move downwards towards the middle of the Earth! We know this from the second thing Newton told us (his Second Law), which is that a force creates (or tries to create) an acceleration, in the direction in which the force acts. If the person is not sinking through the ground, there must be an equal force propping him/her up, preventing acceleration. And this force is termed “ground reaction force” (GRF). 

 

I like to think of GRF, when it refers to human actions (as opposed to rockets being propelled forwards because the gas they eject backwards pushes them forwards) as “ground resistance force” or a resistance offered by the ground, a “purchase”, if you will, against which the muscles of the body can forcefully push off to create movement. 

Biomechanists use a variety of tools to measure GRF. A force platform/plate is made up of strain gauges (among other materials), and as a force is exerted on such a material, it deforms, changing the electrical voltage of a circuit connected to it in proportion to the amount of force applied. A force platform is thus able to measure the reaction force from the ground in three dimensions – vertical (the largest) and two shear forces (resulting from the friction between the two objects in contact) which act in the front-to-back (antero-posterior) and the side-to-side (medio-lateral) directions.

 

A force platform can also tell us the location of the point through which the GRF acts. This location is called the center of pressure (COP), and is the location (with respect to the center of the force plate) of the point that the resultant GRF (a weighted average of all the small reaction forces acting at each point of a foot that is in contact with the ground) is acting from. Ideally, to be maximally beneficial for biomechanical calculations of the golf swing, two force platforms should be used – one under each foot. The two force plates can provide GRF in three dimensions (directions) for each foot, and COP under each foot, which are then combined as a type of average (weighted mean) to inform the quantity and location of GRF from both feet together. 

 

Once again, GRF is a force, represented by the long (almost) vertical blue arrows (vectors) in the picture below. The point of application of (resultant) GRF for each foot is termed the COP and is represented by red dots. Finally, the location of combined GRF (no line to represent it) is the combined COP, represented by the yellow dot.

 

 

One other important measurement often used by biomechanists is the whole body’s center of mass (COM). It is the body’s balance point or the point of concentration of its mass. It is calculated as the (weighted) average of the COM of each body segment (the big blue ball in line with the pelvis in the picture above). Thus if the arms move towards a golfer’s trail side, the COM will shift very slightly to that side (slightly because the mass of the arms forms a small part of the mass of the entire body, and COM is a combination of the COMs of all individual body parts). 

 

A final point to mention. Biomechanists usually think of “weight shift” as COM shift. Conversely, some biomechanists have assessed “weight shift” as COP movement or the quantity of GRF through each force plate, because they try to stick to what they feel golfers and coaches understand by weight shift.

 

Part II of II – three important body movements for the creation of club speed

 

Now for the nuts and bolts of how golfer-ground interaction has been understood and misunderstood by the various stakeholders – golfers, instructors, golf biomechanists. Research has shown that three downswing body movements are related to club speed – towards target weight shift, rotation of the torso, and vertical lift (also termed by some as “thrust” or “launch”). All three are measurable through a combination of GRF magnitude, and/or COP and COM positions.

 

Downswing weight shift. This has been assessed through either the magnitude of vertical ground reaction force under the lead foot during the downswing, or through the distance the whole body’s center of mass (COM) moves towards target. One review study (“A Review of Biomechanical Differences Between Golfers of Varied Skill Levels” by Lindsay et al., 2008, http://fitforegolf.com/uploads/3/4/1/4/34149388/lindsay_2008_pro_vs_rec_biomechanical_review.pdf) stated that skilled golfers had an average of 12.3 cm ± 3.7 cm of COM movement towards the target during the downswing, and less skilled golfers had both decreased, and delayed, weight shift. A large range of COM shift is thus difficult for most golfers who may not have the speed and strength of skilled golfers. Moreover, in my opinion, the reason many golfers have the ubiquitous slice is because their center of mass “hangs back”, while the body begins its inevitable rotation, making the clubface move across the ball. 

 

One recent study of skilled golfers with a golf handicap of 3 or less (“Effects of the golfer–ground interaction on clubhead speed in skilled male golfers” by Han et al., 2019) found that the combined COP shifts quickly to the lead foot between the events of top of backswing and early downswing arms (lead arm parallel to the ground). The COM, in the meantime, shifted towards target at any time from the mid backswing to the early downswing (club shaft vertical position in both cases) events, and then decelerated. That would make for a rather variable phase for this movement to take place within.

 

The above study also found that a greater (perpendicular) distance between the COM and the lead foot GRF vector line was significantly correlated with club speed (medium correlation only). Such a distance is often referred to as the “moment arm” (thick horizontal orange line in the picture below). Moreover, the moment arm line is longest (maximum magnitude) close to lead arm horizontal in the downswing. When the moment arm is longer OR the GRF force is greater (a longer vertical blue GRF arrow), there would be greater angular rotation (thick orange arrow above the golfer in the picture below).

 

So, according to the study, larger moments (turning forces), associated with greater club speed, would happen when the distance between the COM and the lead side GRF vector was greatest. That could happen either if the lead side COP (location of pressure under the lead foot) shifted ahead of the COM really quickly, or the COM remained far behind. BUT the study found that the COM might, for some golfers, move forward earlier (during mid-backswing to early downswing positions) in the golf swing than the combined COP (yellow dot in picture above), which moves towards target between the top of backswing and lead arm horizontal during the downswing. Thus the golfer would really have to “hustle” to get the combined COP ahead! 

 

Moreover, we know that only skilled golfers move the COM towards-target by an average of 12.3 cm. And the COM staying back may cause the dreaded slice! Even if golfers were to have the speed and strength to move pressure (COP) forward quickly, the COM being far behind to produce a longer moment arm (thick orange line) is problematic from a safety perspective too. The expected angular movement would cause greater trail-side side-bend (lateral flexion), which is known to be a big factor in low back pain. The orange arrow at the top of the picture above indicates the direction in which the COM-GRF relationship creates movement.

 

How to reconcile all of these facts? The fact of the matter, dear golfer, is that all of these research findings come from observational research. They can only tell it like they see it. They can only claim a correlation, not a causation. To claim a causation, one must rule out all other likely causes of the phenomenon being observed. And there IS another very big “likely cause”. That is the undoubted strength and speed of the golfers that were studied in the above studies. In other words, the golfers are probably able to shift the COM towards target quickly in the extremely limited time between having it as far as possible behind the combined COP at downswing lead arm horizontal as possible. 

Finally, regardless of how the COP and COM move during the downswing, traditionally 75-80% of body weight has been expected to be on lead leg at ball impact, according to one study (“The effect of alterations in foot center of pressure on lower body kinematics during the five-iron golf swing” by Faux et al., 2019). However, the authors opined, for the stability of the swing which would minimize ball contact variability (and prevent knee injury!), the COM should be directly above the COP, at the time the COM is accelerating maximally. This was the first golf research looking at ways to minimize variability, and there is NO research on improving direction control or acquiring ideal ball trajectory. 

The solution for all golfers (even if they’re highly skilled, because under certain circumstances and with certain body positions, their bodies too become incapable of correct sequencing of the many downswing movements) is to keep the COM and COP closer to the lead side throughout the backswing, so that during the downswing, anyone can move both COM and COP towards target with much less effort!

 

Downswing vertical lift aka launch aka thrust

 

It is known that the longer the length of the “lever arm” of any mechanical device, such as the lead arm-club system at impact, the higher the speed (linear velocity to be precise) of the golf club (http://waddengolfacademy.com/biomechanics/Sanders%20and%20Owens%20Hub%20Path.pdf

by Sanders & Owens, 1992). In order to achieve this, a very popular concept has been to ask golfers to do a squat-jump type movement during their swings. While some famous coaches like Mike Adams would have golfers do both the squat and the following jump-up during the downswing itself (https://www.youtube.com/watch?v=_OwN-m92b8E), others state that the squat should take place during the backswing (the best players can squat about 2” in the backswing and jump 2” up for a total excursion of about 4”), and the jump-up during the downswing (Greg Rose of TPI, https://www.youtube.com/watch?v=zeFCPaYFTzo). The vertical jump is described in the latter video as creating GRF, which “goes back up from the legs to the core”. This creation of explosive GRF, according to Rose, is the most important of four power sources (the other three, according to him, being rotary power which can also be harnessed from vertical thrust; arm chop; and wrist). 

 

Once again, all these are correlational findings. Thus such movements are possible only for the super strong and fast athletes (and only in the right circumstances), and if they are super fast, they could probably jump up in mid-air during the downswing, land on their feet and still connect the ball with great club speed! One must always keep in mind that the entire downswing lasts a mere 1/3rd of a second or less. The less movements made during that tiny moment in time, the more efficiently the central nervous system can coordinate the rest. So, my concerns with the squat jump are: a) it would thrust both shoulders up equally, not merely the lead side which is what is needed b) what if someone (typically a slower someone) gets maximum height of the lead shoulder AFTER impact – wouldn’t a lot of the benefit be lost? c) what about the injury factor to the knees, the hips and the lower back with all the compression that those joints must be maintained in during the fast speeds of the golf downswing? d) Is there less smoothness to the downswing (measured as “jerk” or the rate of change of acceleration), resulting in inconsistent contact? e) Is there a simpler way to achieve maximum lead shoulder height at impact?

 

Once again, the solution for all golfers (even if they’re highly skilled, because under certain circumstances and with certain body positions, their bodies too become incapable of correct sequencing of the many downswing movements) is to simply stand up taller (lead side higher) and keep the lead side of the torso higher from address to impact (once again lead side higher)!

 

Downswing torso rotation 

 

The third source of power from the body is torso rotation, which has been called a proximal – to –  distal (pelvis before shoulders/thorax) rotation or a kinematic sequence. The main reason that this is so important is that the large, powerful core muscles of the body get stretched during the backswing and can therefore contract more forcefully during the downswing, much like the stretched elastic of a slingshot-catapult releases more forcefully. As the golfer pushes backwards through the trail foot and forwards through the lead foot (measured as antero-posterior shear forces through force plates), to create stability in those directions, the powerful trail side core muscles use the ground as purchase to rotate forcefully off of. This movement will happen without a golfer’s volition, because stretched muscles will contract! 

Once again, research has shown that more skilled golfers are able to rotate to faster. In the words of Okuda et al. (“Trunk Rotation and Weight Transfer Patterns between Skilled and Low Skilled Golfers”, 2010, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3737954/), “Pelvic horizontal rotation in the downswing motion occurred significantly earlier with a rapid weight transfer to the lead foot in the skilled golfers while the low skilled golfers showed a delay in these motions”. 

There are two important points we can assess from the study. Firstly, less skilled golfers cannot rotate and shift weight as fast, so perhaps the weight may not get shifted adequately to the lead foot before rotation begins, leaving “weight” behind and perhaps creating curved shots. 

 

Secondly, note that the authors refer to the rotation as a “pelvic horizontal rotation”. However, golfers are typically asked to make a backswing by rotating the shoulders around a spine which is flexed forwards at address, resulting in an oblique position of the torso at the top of the backswing. From this position, a golfer’s pelvis is expected to fire on a mainly horizontal plane during late backswing or early downswing. As mentioned earlier, muscles that are stretched contract more forcefully. Which muscles have been stretched to be able to produce a horizontal downswing rotation from an oblique top of backswing torso position? The main muscle group for forceful downswing torso rotation is the trail side external oblique. This muscle group has both vertical and horizontal fibers. When the torso is rotated obliquely, the vertical fibers may be stretched to a greater extent, resulting in a more downward rather than targetward movement of the torso, and perhaps a more steep shoulder path (and thus arms-, and club-path) than desirable. 

 

And once again, therefore, the solution for all golfers (even if they’re highly skilled, because under certain circumstances and with certain body positions, their bodies too become incapable of correct sequencing of the many downswing movements) is to position the body so that there is minimal and optimally timed torso rotation.

 

Kiran Kanwar, PhD (biomechanics + anatomy)

LPGA Master Professional (thesis in “types and causes of golf swing-related injury”

Golf teaching experience of 30+ years.

Website: www.mgs.golf

Ground Reaction Force – What it can and cannot do for Golfers

Ground Reaction Force – What it can and cannot do for Golfers

 The theory, and some examples that demonstrate its meaning:

What, first of all, is the much talked-about ground reaction force (GRF)? The free dictionary defines GRF thus: GRF force is offered by support surface, equaling and opposing force due to body mass passing through the foot to the ground surface.(https://medical-dictionary.thefreedictionary.com/ground+reaction+force). GRF is a spin-off word used mainly by biomechanists to describe one aspect of Sir Isaac Newton’s Third Law of Motion (L-3) – the Law of Action and Reaction.

To quote the great man himself, “To every action there is always opposed an equal reaction: or the mutual actions of two bodies upon each other are always equal, and directed to contrary parts. If you press a stone with your finger, the finger is also pressed by the stone.”

In modern day English, this simply means that when two objects are in contact, they push against one another to an equal extent, whether some movement is the result or not. For instance a person standing on the ground is pushing the ground and the ground is pushing him back, but neither moves. So L-3 is valid even when there is no motion involved. Moreover, it can occur between any two objects, eg. two footballers running into one another or when a person pushes her hand against a wall. GRF is merely the reaction force when the ground is one of the pair of forces acting on one another.

When so many action-reaction forces exist, why does GRF take on so much importance? Simply because most human movement takes place as a result of human-ground interaction. As a result, biomechanists use force platforms to measure the magnitude and direction of the interaction. One scientist describes the use of force-plates (platforms) well by stating that, “Considerable confusion exists about the origin of the forces measured by a force platform. The best way to understand these is to think of the force platform as a whole-body accelerometer, and any acceleration of the body will be reflected in a reaction when at least one foot is on the ground. Thus ground reaction forces reflect accelerations of the body’s centre of mass.” (see http://www.clinicalgaitanalysis.com/faq/grfs.html) Another paper explains the use of force plates similarly, “The ground reaction forces, as measured by a force platform…are an algebraic summation of the mass – acceleration products of all body segments while the foot is in contact with the platform. (see http://www.wseas.us/e-library/transactions/systems/2009/29-755.pdf

Thus, given all the evidence, in simple terms we can state that GRF as measured by force-plates, is a mere reflection of a body’s acceleration, while incorporating the constant factor of its mass/weight. It is known that when a body stands unmoving on a support surface such as the ground, the GRF is equal to the body’s weight (W). If the body then accelerates (which simply stated means it slows down or speeds up), the GRF is no longer equal to W, but more or less than it.

 

So, as an object’s mass (here weight) cannot change, how are GRF and acceleration related? One university’s lab assignment (see: https://www.asu.edu/courses/kin335/documents/Linear%20Kinetics%20Lab.pdf) sheds some light on the topic. “Most of our movements ultimately rely upon our interaction with the ground…what is important to keep in mind is that the GROUND REACTION FORCE IS LARGELY UNDER OUR CONTROL VIA COORDINATED MUSCLE ACTIONS. BY PRODUCING A CERTAIN COMBINATION OF MUSCLE ACTIONS, WE ULTIMATELY PUSH AGAINST THE GROUND WHICH PUSHES BACK AGAINST THE BODY WITH AN EQUAL AND OPPOSITE FORCE.”

 

Moreover, it is known (from Newton’s second law of motion) that “if the upward push of the ground is equal to the earth’s downward attraction (i.e., weight), the net force on the body equals zero and the resulting acceleration is zero. If the ground reaction force is greater than body weight, there is a net positive force acting on the body and the acceleration is positive. Finally, if the ground reaction force is less than body weight, the net force on the body is negative and the acceleration is negative.

 

One book titled Neurobiomechanics of Human Movement (Roger M. Enoka) states that each body segment influences the GRF, based on its mass and its acceleration, and adds that about 50% of a runner’s acceleration is accounted for by his trunk and head, while each leg contributes 17% and each arm 5%. The book incorporates a great example to further illustrate its point. It states that the height achieved in a vertical jump depends upon vertical velocity at takeoff, which in turn depends upon the vertical component of the GRF. The book adds that GRF and acceleration graphs thus always parallel each other in a vertical jump.

 

Putting it all together, GRF is the reaction (or one might perhaps say “interaction”) created by human muscle forces as they push down into the ground, and larger body parts with their larger muscles influence the interaction to a greater extent. So what’s all the fuss about in using GRF to increase club speed in golf? Another way to think of GRF is as a RESISTANCE force. The harder the push down by human muscles and the firmer the surface on which a person stands, the better they can use that surface to create movements off.

 

Converting the theory to all things golf

 Three movements in the golf downswing have been recognized as increasing club speed and they all involve ground-golfer interaction. They are  “weight shift” towards target, body rotation and trunk elevation.

 

The best way to increase the early build-up of speed is by trying to increase all three of the above. Before we try to analyze how best to do that, it might be a good idea to first of all understand when in the downswing each of them happen and their relative contribution to club speed. Only then should we discuss the best methods to increase those movements.

 

The first movement to take place is weight-shift, a linear move of the body towards target. This movement is useful to give some starting momentum to the body. The second movement is rotation of the torso – pelvis followed by shoulders. The rotation movement uses the forceful contraction of the large muscles of the core to generate torso speed which is eventually passed on through the arms to the club. Finally, late in the downswing, the lift of the lead-side allows the longest possible radius of lead arm and club, for maximum possible linear velocity of the club. No research exists on the amount each of the three movements contributes to eventual club speed!

 

How can the ground be used for each of the “big three” movements? Shear force (an away from target push) through the trail foot moves the body and the center of pressure towards the lead foot. As the golfer pushes the trail foot away from target, “equal and opposite reaction” make the body move towards target, for weight shift. Next, once the center of pressure has moved forward, both feet can be involved in an oppositely-directed force couple to create rotation of the torso. (Read this wonderful paper which reports similar first and second movements in baseball batting: https://www.jospt.org/doi/pdf/10.2519/jospt.1995.22.5.193). Finally, a push-down of the lower limbs will help to accelerate the torso upwards. Watch Alex Noren making practice swings in any 2018 video to understand how people are being trained in order to produce this latter movement. I witnessed Noren actually being trained to do that during the 2018 Genesis Open, and saw him making practice swings with that same move on TV subsequently.

 

All three GRF-using movements are rather misunderstood, in my opinion. Weight shift? A small amount of it is useful in order to get the downswing momentum going. However, to shift “weight” or foot pressure on the ground back a lot, and then to shift it forward again is excessive. It is known that skilled golfers are able to shift body mass forwards by about 12 cm (see this paper: http://www.fitforegolf.com/uploads/3/4/1/4/34149388/lindsay_2008_pro_vs_rec_biomechanical_review.pdf ), while less skilled golfers have neither the muscle strength nor the speed to pull that off. Our goal should be to get some weight shift in the forward swing, without any excessive away-from-target movements during the backswing. How? By starting out with some slight extra pressure on the trail foot – MGS style!

 

What about rotation? While the feet finding firm support on hard ground will offer the muscles adequate purchase to push off of, it is important to know which exact muscles produce the body rotation we golfers need. The main rotators of the body are the large torso muscles – the external and internal obliques. To get these muscles to contract maximally, they need to be stretched during the backswing and then they need a firm foothold to be able to contract forcefully to rotate the trunk. And this is best done by having zero up-and-down or side-to-side movement of the torso at the time the core muscles are contracting most forcefully. Did you know that skilled golfers’ chins do not move targetwards during impact? (see “Hub movement during the swing of elite and novice golfers” by Sanders, R. H., & Owens, P. C. (1992). The MGS, with its pre-swing rotation and subsequent in-swing arms movements stretches the large core muscles, and the stillness of the body the MGS requires helps the powerful abdominal muscles to contract very forcefully while the feet are firmly planted in the ground. Such stillness is an integral part of the MGS.

 

Finally, in order to get their “verticals”, people are actually, these days (a le Alex Noren) being trained to squat-jump, right in the middle of the golf swing. That is problematic because the downswing lasts only 1/3rd of a second. A golfer would have to be very fast and strong to first lower the body and then raise it maximally, all before impact. The fastest, most skilled golfers do it to an extent, but even their lead shoulders are maximally high after impact, indicating that they could not raise the lead side adequately at the moment of impact. The solution? Grab hold of the ground from the beginning of the backswing and let the rise of the body be a natural consequence of the design of the golf swing (depends on the type of golf swing, ofcourse!). BUT this can only work IF there has been no change of body-level in any direction during the backswing. (see pic of maximizing verticals AT and not AFTER impact below).

Forget the science for a moment, think of it in a common-sense manner. The method of achieving “verticals” is the silliest of all the movements being prescribed to the top players in recent years. A real “countermovement-jump” has an important contribution to its quantity of movement from freely swinging arms. In golf the arms are attached at the grip and are required to move in a specific manner as the golfer tries to squat-jump. Moreover, how can a golfer who is shifting weight, rotating and squat-jumping during the downswing guarantee that they will put maximum pressure into the ground at the crucial moment of impact? Finally, no one has researched the exact contribution of each of the three movements towards club speed development, so how can we know which one to maximize? (See GRF representation of a golfer’s existing rotation on force-plates on the left, and with MGS on the right, in the pic. below)

In conclusion, GRF does exist, but is not an active force that can push people hither and yon. It is more of an interaction at the interface of two “objects”. One object, such as the human, should be able to change its quantity of pushing effort, and the other object, such as the ground, should provide passive, inert resistance to sinking through. To utilize it in golf means one should grab hold of the ground before the backswing begins and then not make any movements which reduce the downward push of the feet. No excessive movement side-to-side, no rotation of the trunk during the backswing (finish that before the swing begins!) and no jumping down-and-up during the downswing. That is the best way to utilize the ground and anything else does not maximally allow a person to “hold on”!

The Main Muscles of the Golf Swing – Their Use and Misuse

The Main Muscles of the Golf Swing

Some very basic anatomy:

A joint is a place where two bones come together. They never actually touch but are connected through a joint capsule. When movement takes place, it happens because two bones, connected at the joint,  are brought closer together or moved further apart. This is the role of whichever muscles are inserted on either side of a particular joint.

Some muscles are long or wide enough that they cross multiple (two or sometimes three) joints, and can thus move all the joints they span. However, it is known that when muscles span two joints, they are not able to move both as efficiently at the same time. For instance, make a tight fist. This involves a flexing of the fingers. As you bend the wrist backwards the fist remains tight but if you bend the wrist towards your palm, the fingers loosen a bit. Why? The muscles that flex both the fingers and the wrist cannot be maximally efficient at both joints. The term for that “incapability” is “active insufficiency” (ie when the muscles are actively trying to contract at both ends there is an insufficiency in their capability).

So this affects the golf swing how? In a manner no one realizes because most of those influencing how the golf swing is made do not have a deep understanding of the design of the human body and thus its capabilities with respect to how best to make a golf swing.

What the golf downswing must achieve:

Regardless of what a golfer does in the downswing, in order for a ball to go high, straight, and far, the club must be delivered to the ball from an inside path, with an adequate angle of approach (attack) and at maximum speed. That’s all. Neither the club nor the ball care about the design of the human body!

A marriage of anatomy and the ball flight laws:

If the club must be delivered from the inside (the most important of the five ball flight laws – but see the note at the bottom to understand current thoughts on the subject), then the arms and trail shoulder (right for the right handed golfer) must also be “arriving from the inside” by being behind and below the lead (left for the left handed golfer) shoulder, elbow and wrist.

Most golf swings are, from an anatomical perspective “over the top” (OTT) and therefore not “from the inside”. Even the best of them. How so? Because either the trail shoulder is forward (towards the ball/target line) of the trail toe at impact (when viewed from down the line), and/or the trail thigh and knee point forward (towards target) and down, and/or the trail elbow is behind  the trail shoulder when a vertical line is dropped from the shoulder downwards. In the picture below all golfers are PGA/LPGA Tour players.

OTT happens because the start of the downswing is predominantly downwards rather than rotational (as with less skilled golfers) or because the pelvis rotates so early and so fast (as in more skilled golfers) during the downswing that the trail thigh or shoulder gets pulled down and forward as well – too much too soon.

So what muscle-positions at the top of the backswing cause the excessively downwards and forwards movement of the trail side? The higher right shoulder (which is always lower at address and impact so why do all golfers raise it at the top?) and the fact that the arms have moved away (to a lesser or greater extent) from the body. This makes some powerful muscles of the shoulder and trunk stretch, so that they will contract more forcefully. Moreover, the more they are stretched upwards (because everyone raises the trail shoulder), the more they will contract downwards. See the pictures below of the same golf pros as above in their top-of-backswing positions.

The three pictures below show 1. a rear-side view of the powerful lats i.e. latissimus dorsi muscle that moves the trail upper arm away from the body during the backswing,  and 2. and 3. the external oblique (EO) muscle of the torso, which, depending on which direction it has been stretched in during the backswing, can drop the torso downwards or rotate it.

 

 

With all these powerful muscles stretched in an upwards direction, a less experienced golfer who has not developed sophisticated lower body movements will simply hit straight down. He/she cannot help it – that is all that his/her muscle-positions at the top will permit, during the downswing. More skilled golfers, trying to generate a good ground-up body sequence, somehow make a race against time to rotate their pelves towards target in the early downswing. However, because the torso muscles are all interconnected,  pelvis rotation inevitably results in the upper trunk being pulled down and forward too. So, as long as, at the top of the backswing, the trail side shoulder/shoulder girdle is higher and the trail arm has moved upwards too, resign yourselves to some degree of OTT!

With the Minimalist Golf Swing, its “magic move” is to keep the trail shoulder and trunk lower than the lead one, throughout the backswing. This stretches the trail side external oblique muscles more horizontally than upwards so they will rotate the trunk rather than pull it downwards. What about the lats? It is two-jointed muscle, connected at the spine and also at the upper arm. So when the “trail-side-lower” of the MGS backswing keeps the muscles active at the spine, by keeping the spine in side bend, the lats are not able to be stretched as much at the upper arm, and so do not aggressively pull the trail arm towards the body while the trail side EO is moving the torso downwards.

Imagine a golf swing with no need to think about ground-up sequencing because the pelvis cannot help put rotate early in the downswing. Imagine a golf swing where the depth of the divot can be manipulated merely by the height of the hands; or the plane of the swing merely by how closed the shoulders are at address. Imagine never having to jump up and down with the torso to harness ground reaction force because merely pushing down through the feet is adequate to “use the ground”. Imagine, moreover, never having to go extra steep with the club shaft in the backswing to shallow out its downswing plane (not anatomically repeatable unless the pelvis rotates out of the way fast), or making the hand path steep to shallow the club shaft’s downswing path. What a load of nonsense golfers have been fed by those with inadequate scientific knowledge in all the aspects of kinesiology. All one has to do is place the entire body, at the top, so that all the bodies joints can EASILY be unbent or untwisted, in the manner most suitable to their design, in the right sequence, for their desired positions of the downswing.

Note:

With the advent of sophisticated launch monitors, people have noticed that in order to produce a straight shot, the slightly steeper angle of attack (ie a descending move of the club towards the ball) required for the irons is best matched with an out-to-in path, and the ascending club angle required for a driver shot, with an in-to-out path. Common suggestions that are made to facilitate that include moving the ball position suitably or using even certain trunk side-bending angles at address. However, we have just proved that it is the direction of stretch of core muscles at the top that will determine how the body and arms, and thus club, move during the downswing, so any preparatory positions are trivial.

Additionally, the modern swing (and its many variants) is a narrow, confined movement so there is no place or time within which to reroute important joints/body parts in order to allow the arms a truly “inside approach”. Thus, OTT has become “par for the course”. This natural OTT and its intrinsic out-to-in path at impact may work for the irons (nevermind the unnecessary and injuriously deep divots it digs out). So the “experts’ have merely found a way to tell you to continue doing what you do most naturally. For the driver, the reason why even the pros still have inconsistency is that they continue the out-to-in path (albeit to a lesser extent) – because their EO and lats cannot help it! Ofcourse, a golfer with a long, loosey-goosey arms swing will often (not always) be able to drop the arms into and inside  the “slot”, but this will depend upon timing, which, research shows,  changes under pressure.

Finally, the “magic move” of the MGS is the only one that prevents any degree of OTT. It is designed for perfect – and unconscious – downswing sequencing so that a golfer cannot help but arrive at the ball from the inside, on a consistent basis.

Tiger Woods – The Anatomy of his 2018 Golf Swing

An evidence-based case study with screen shots from TW’s February 2018 swing to illustrate.

Problem: inconsistency with the driver, and misses to both the left and the right. In golf terminology, a swing with hands that are “flippy” ( and sometimes even “late”).

What does he currently do or believe he should do? (based on youtube videos of his 4 coaches and what they have added to his knowledge).

As a kid he was always “stuck” with his arms behind his rapidly rotating trunk.

  1. One coach suggested he should: have a slightly weaker left hand grip and a slightly narrower stance during set-up. Then make a takeaway which should set the club “up” a little earlier, have the clubhead in front of hands a little longer, have a higher right arm (key), then round off his left arm and place it a little flatter at the top. During the downswing, he was told to get the club down in front of body, then arc it off with a little bow of the left hand. All this, he was told, would get the arms in front of body instead of position the club laying down behind him in his downswing. This made his distance about 10-15 yards less.
  2. Another coach suggested that the solution would be to place his club shaft, during the backswing, on or above shaft’s angle at address. This would help to bring the club more in front of his body and prevent the upright shaft position (slightly across the line) of the top of the backswing, from flattening during the downswing and thus becoming stuck close to impact.

Subsequently, Tiger sought more science-based information to improve further:

  1. His next coach’s general beliefs were to help a player understand what is happening at impact, understand clubface position, club path and angle of attack. He believed that unnecessary movement should be minimized (what is necessary or unnecessary was not explained, perhaps the coach used a ‘lean the body over the lead side during the backswing’ or stack-and-tilt-type concept to minimize motion?). Then in one video showing this coach’s instruction to another player, he can be seeing saying that, “shear force is lateral force so if you’re going to move it forward you’re going to rotate anyway. Get heavier here (on lead side approximately in mid downswing) to get lighter and jump up. Forces are going down into the ground and now they’re going to come back up into you.”

Finally a more recent coach who has never made a video while coaching Tiger, in general believes that:

  1. To hit a draw, a golfer should have the left side higher and put more pressure on the lead foot. Then during the backswing, a golfer should make a full turn of the trail side behind one (including of the hips). This will put the pressure into the trail foot so a golfer can drive the body forward as he/she swings down. This coach has also said that body motion through the golf swing should feel like an upper cut with the right side of the body working a bit under and up instead of throwing a hooking type motion where the right side is higher than the left.

So, what is Tiger doing currently? Probably a mish-mash of ideas gleaned from here and there:

2018 Backswing: mainly the lead knee becomes exaggeratedly flexed, and with it there is lead side trunk lateral flexion (closer to a stack and tilt look). The arms swing inside. It may be argued by 3D purists that there is some “hip rotation” but mainly the backswing is a drop-the-lead-lift-the-trail side, move-the-arms-inside swing. Considerable X-factor of limited pelvis versus more shoulders, even though shoulder rotation may not be as pronounced as before.

2018 Downswing: the trail knee flexes until both knees are level (probably squatting in order to push off the ground). By mid-downswing the early squat is accompanied by a vertical shaft (considerable wrist lag) and a head that is virtually buried between the shoulders. During his downswing he relies on the upwards movement (rather than the rotation) of his torso to straighten the wrists and therein lies the problem. By the time the wrists do begin to straighten from their exaggerated lag, the vertical push upwards has caused the trail elbow to straighten, and, as the mainly vertical movement of the downswing continues, there is great suspense as to which action the wrists will take – flip or delay? (doesn’t matter that he’s not “stuck” with his arms lagging behind a fast-moving torso, now his wrists are “stuck”!)

If the “big three” of swing speed production are side-to-side “weight shift”, up-and-down vertical force production and rotation, TW’s 2018 swing is mainly up-and-down during both the backswing and the downswing, with little weight shift and no pure torso rotation.

Why does that matter? Because, as stated in one study, correct sequencing of pelvis-before-shoulders can give better direction, as well as greater distance. This is the only researched information we have on producing better ball direction, while there is a ton of research on increasing speed. Moreover, “correct” sequencing is nothing other than a rotary movement of the pelvis before the shoulders. It also matters because a swing with so much “body drop” during the downswing (not to mention head forward drop) can create compressive loads on the neck, the lower back, the hips and the knees.

So is it being advocated here to not jump up and down or move side to side? When so many people have used their launch monitors and pressure/force plates to prove that golfers who “push off the ground” better create more club speed? While it is very important to “use the ground”, there is a much simpler way to do it. See the footnote for details on what exactly “using the ground” means. If not a squat-jump, how can Tiger create both the speed he is famous for, and more consistency of direction? The suggestion here is to minimize the range through which side-to-side and vertical motion take place, and maximize rotation!

Of the previously mentioned “big three” power producers of the body, both side-to-side (weight shift) and up and down (squat jump) come at a price. The muscles of the body need to “use the ground” to push off, while contracting forcefully to create movement. However, rotation is completely free, because muscles that become stretched merely by the act of rotating during the backswing, are stretched and primed and ready to contract forcefully during the downswing, and they do this without volition, that is, subconsciously. Is there any proof of this? See results below from a simple class project showing how much more the external oblique (core) muscles fire with this swing system [ensemble average of 12 participants, mixed ages and handicaps, over a single session golf lesson with only 10-15 practice shots between pre- and post-measurements].

So what should Tiger to improve ball-striking and consistency and reduce the scope for further injury?

He should use a swing which does reduce all unnecessary motion (up and down and side to side), has been subjected to research at many phases of its development over 25 years, and can be explained in terms of muscluloskeletal anatomy, neuro-anatomy, motor control and biomechanics.

This swing (the Minimalist Golf Swing/MGS) requires:

1.Rotate the entire torso while standing upright (the giant mass of bone that makes up the pelvis can only be efficiently rotated when the entire body, from ankles to neck also rotate). This is because pure horizontal-plane torso rotation is most efficiently obtained in an upright posture, according to one study. (Can you imagine useful pelvis rotation from either of the two positions below?)

2. THEN the posture and grip are taken so as to not undo the rotation achieved.

3. Finally, the head and the spine are tilted away from target, and unlike all other swings, STAY at that angle throughout the backswing, by keeping the trail ear, shoulder, elbow, wrist and waist lower than their lead-side counterparts. (If at address and impact the trail shoulder is lower, why waste time lifting it during the backswing, only to have to drop it down, while making a ton of other motions, during the 1/3rd second the downswing lasts?).

This swing positions body mass closer to target to start with, so that little weight shift is required. It also keeps the lead shoulder higher throughout the backswing so that little vertical movement is required to increase lead shoulder height (the main purpose of the “push up” movement). With these moves (and a few other minor arms position adjustments which are not relevant to the present discussion), not only is rotation assured but the “bad” moves of the upper body mis-sequencing the downswing are ruled out, as is the likelihood of the arms pulling the club to the left (for a right-handed golfer), thus instantly making the “pull” group of shots unlikely.

This swing actually uses the ground in a much more efficient manner, as all it requires is to push both feet firmly into the ground during takeaway. As the trail side of the body remains lower throughout the backswing and there is little lateral movement, the strong core muscles use the firm connection (purchase) with the ground to rotate forcefully off. After all, which boxer actually sways or moves in any direction at the moment of throwing a strong punch? Try this drill: push down through your feet and quickly rotate your trunk versus be light and loose through your feet while trying for quick trunk rotation. Essentially, this swing positions the body not at the “top of the backswing” but at the “top of the downswing”, so that the unnecessary, excessive movements of transition go away, all the body’s joints are positioned for their actual roles of the downswing, and all the important power muscles are primed and ready to fire.

The moral of the story for you and Tiger Woods?

Cut out excessive side-to-side and up-and-down movement (imagine trying to shoot at a target while standing on a vibrating platform!) and increase the rotation. It’s free, it’s easier on the body, and it provides ground-up sequencing – the only movement known to produce both better distance and direction (a baby draw with a driver). As for being “stuck”? The pelvis rotating from closed to square prevents it being too open to the arms, so they are never “stuck behind”, and a correct sequencing of body rotation prevents the wrists from being “stuck”.

The promised footnote:

“Using the ground” has become a popular notion in recent years, with many advocating pushing forcefully downwards into the lead leg with a flexed knee during the downswing, so that the ground can help push the golfer up. What is the purpose of the push-up? Merely to get the lead arm to be as high as possible, so that the radius of the swing’s arc is maximal at impact, to give the golfer the greatest possible club velocity when contacting the ball.

“Using the ground” is another way of saying using “ground reaction force” (GRF). This concept is based on Newton’s Third Law of Motion which says that every action will have an equal and opposite reaction (and this can be in any direction such as horizontal when pushing against a wall, or vertical when pushing against the ground). However, many in golf have claimed that as the golfer pushes down, the ground pushes the golfer upwards. That is patently untrue. GRF is merely a passive force and can be used to slow down (as when landing from a jump), or speed up, movement. The slowing down takes place because the ground offers a resistance to continued movement. The speeding up happens as the body’s muscles are able to use the ground as “purchase” to push off against. If a person does not have adequate muscle strength/speed they may simply stay ‘down” and never have enough muscle strength to use to push up off, IN TIME FOR IMPACT (ie in the 1/3rd second a downswing lasts!). Even Tiger’s lead shoulder, despite his strength/speed from extensive fitness routines over many decades, is at its highest after impact (see picture below).

Even an average golfer can get phenomenal lead shoulder height by using the MGS and keeping the lead shoulder high at the start of, and throughout the backswing. No need for any time-consuming, tissue-damaging squat-jump:

Women’s Accessories at the 2018 PGA Show

Women’s Accessories at the 2018 PGA Show

The 2018 PGA Show held in Orlando, Florida, had nearly 40,000 golf industry attendees and more than 7,500 PGA Professionals who visited the over 1000 exhibiting companies and vendors, while they traversed the nearly 10 miles of aisle space at the Orange County Convention Center. One of those aisles was reserved for, wonder of wonders, women’s accessories, and the most eye-catching booth in that aisle was that of Sydney Love bags.

This handbag and luggage making company that has made these products for over 17 years, has diversified into golf (and tennis) products that include golf handbags, duffle bags, totes, ball, tees, shoes and cosmetic bags, and even actual golf bags (the ones that carry clubs). And each piece is delightful, whimsical and innately appealing to a female golf addict. The bags are designed by Christine DeGenarro who, after teaching design in New York, has relocated to Florence, Italy, from where she combines sophistication and innovation to produce original, captivating golf bag designs.

So it was very exciting to come across this amazing product line, and check out not only their well crafted bags but the cutest golf-shoe keychains and metal business card holders too. The owners are a brother-and-sister pair from Pennsylvania, and their brand – Sydney Love – is named for Pam Haber, the co-owner’s, daughter (picture of Pam and her many bags, including THE ONE). There is a bag for everyone, the owners claim, whether it be traditional or daring, sporty or chic, casual or elegant.

So while my friends and I oohed and aahed about many of the bags, keychains and business card holders, one of them had my name written all over it. A beige-tan colored “classic golfer drawstring tote” with tall skinny women golfers of the 1920s in their long pencil skirts dresses, embroidered all over the bag. The finish is excellent with a lot of attention to detail, and the olde gentlewoman is portrayed not only on the bag but on the medallion zipper pulls, and even on the inside label.

See http://www.sydneylovebags.com/category-s/1863.htm?searching=Y&sort=3&cat=1863&show=30&page=3 to have a look at their range of products.

The Brain’s Control of Movement, The Uncontrolled Manifold Theory and the MGS

The Brain’s Control of Movement and the MGS

[Please read the previous post to understand this one better]

Muscle- or motor-activity of the body is controlled by the central nervous system (CNS) which consists of the brain and spinal cord, and motor control research attempts to analyze how the CNS produces meaningful, coordinated movements of the body. The issue of coordination was first described in 1967 by a famous Russian neurophysiologist and pioneer in motor control theory,  Nikolai Bernstein, who stated that the “difficulty” with co-ordination resulted from the many degrees of freedom that the brain had to choose from. What did he mean by “degrees of freedom”? These can refer to the number of joints and the muscles that move them; or the path and speeds at which the various body parts move; or the number nerve cells (neurons) involved in sending messages from the brain to the muscles that need to move.

Since those early days of motor control and biomechanics (a term coined by Bernstein), the current understanding of the situation is that while it may be considered a “difficulty” by scientists attempting to unravel the marvels of the human CNS, it is actually a great blessing for the body to have many options, especially when some “obstacles” are involved. If for instance, one is carrying a mug of coffee in the hand and has to walk over uneven terrain or push open a door while trying not to spill coffee, it is very useful if the brain can make a COMBINATION of varying shoulder, elbow and wrist movements in order to deal with the situations presented, and prevent us from getting burned by spilling coffee! This is why the degrees of freedom “problem” is now considered a case of “motor abundance” with the brain choosing suitable options based on the obstacles or “constraints” or “perturbations” it needs to overcome. These constraints can be related to the person performing the movement (who could be, for instance, anxious, sleepy, fatigued or injured); the task (which could range from a small putt to a full swing); and the environment (wind condition, wet fairway and slope on which the golfer stands, among others). 

Several newer theories have all attempted to understand motor control. One that is gaining a rapid foothold is the Uncontrolled Manifold (UCM) hypothesis refined, in part, by Mark Latash et al. (see his detailed video of the theory as well as his description of the simple coffee mug scenario): https://www.youtube.com/watch?v=SpRIBpp83uM). This hypothesis states that the CNS chooses from, and uses, all the degrees of freedom, based on the situation that exists, in order to achieve a particular goal (such as hitting a ball with a club). No degrees of freedom are omitted, and they are all “managed” or “coordinated” in order for the goal to be achieved.

The CNS basically makes all attempts to have synergy between the joints along the uncontrolled manifold (no need to worry about what a manifold is at this stage) in order to achieve the task which is – you got it – to keep the mug upright. It does so by allowing as much variability in joint positions as required at the three joints mentioned, but makes sure that the COMBINATION of joint angles is controlled. For instance, some joints might move more and at greater speed while others might move less or at a slower speed in order to KEEP THAT DARNED COFFEE MUG UPRIGHT! Along an “orthogonal dimension” (also not important to understand) no synergy exists between the joints. 

So, because the CNS seeks to conserve the outcome at all costs, and stabilizes the COMBINATION of joint angles (along the UCM) that are important to the outcome, variability along the UCM is acceptable and well managed, in order to safeguard the goal. However, any variance in the orthogonal dimension (even if we won’t worry too much about its definition for now) will have an effect on the outcome of the skill (Motor abundance and control structure in the golf swing by Andy Morrison et al, 2016).

  • The following is a personal opinion based on the following:
    Most UCM research is on single-handed tasks involving only the upper limb, so here goes regarding how the brain controls our swings:
  • Remember how the brain ascribes limited resources to the trunk as compared to the limbs (previous post)?
  • Based on brain resources, could we possible conceive of the arms as forming the UCM so that the brain would preferentially synergize the movements of the shoulders, elbows and wrists in order to deliver the club in a repeating manner to the ball?
  • Could then, the trunk be considered “orthogonal”? This makes sense from both a common-sense perspective and because of the CNS’s overall design. Common sense because who wants the platform of a movement moving while the arms are trying to deliver the club to the ball with great precision? Cos design because the brain was probably not designed with the golf swing in mind, and therefore does not bother to send huge amounts of nerve impulses to body-based movements such as weight shift, torso rotation and upward movement of the trunk?

How perfectly wonderful then if one completed all body-related movements at a relatively slow pace before the backswing even began, as part of one’s set-up routine. With a stable base of support and no in-swing movement of the “orthogonal dimension”, the brain could absolutely “have at it” and be free to vary all shoulder/elbow/wrist positions along the “UCM”, based on the obstacles to be overcome such as one’s fatigue level, the length of the backswing, and the slope of the ground beneath the feet. Which, of course, brings us to the Minimalist Golf Swing, which does exactly that. It is truly so brilliant that only God could have devised it and had a small human creature disseminate the message!

The Brain and The MGS

The Brain and The MGS

The human brain has many roles within the body, and one of them is to decide upon, initiate, and modulate, any movement. How it does so, through a collection of chemical and then electrical processes, requires the study of a vast and not-yet-fully understood field of study – neuroscience. The following is a very basic explanation of how the brain and spinal cord make the muscles of the body work to create movement, and how, amazingly, the design of the brain and the design of the Minimalist Golf Swing are very much in sync!

All that exists in the different areas of the brain is bundles of nerves richly supplied by blood. A single nerve has a somewhat balloon-on-a-string appearance, with the balloon being the “cell body” that conducts all the processes of the nerve cell, and the string being the “axon”, that transmits electrical “messages” to muscle. The parts of the brain that contain cell bodies are called gray matter, while those that contain axons are termed white matter.

The outer layer of the brain is the cerebral cortex made up of gray matter, and inside there is white matter as well as some internal gray, such as the basal ganglia.

The cortex has several parts in it which serve different purposes, but the important parts are the pre-frontal cortex (the decision maker) and the primary motor cortex (the messenger). At the posterior part of the brain is the cerebellum, which contains the templates for already-learned movements, and also works to smooth and coordinate all motion. Finally, at the base is the brain-stem through which messages are passed down the spinal cord to reach, eventually, all the muscles of the body. And there you have it. A very basic description of the parts of the brain and spinal cord that are involved with movement. (The green area in the top right picture below is the primary motor cortex)

The primary motor cortex (PMC) has different parts of it that send messages to muscles in different areas of the body. This very carefully mapped-out “chart” is called the homunculus, and it can be seen that while the brain reserves a large part of the PMC for the movements of the face and limbs, only a very small part is reserved for movements of the trunk. Even the blood supply to the different parts of the PMC follows the pattern of the homunculus, so that different arteries supply blood to those areas that subserve trunk motion, compared to those that connect to the face and upper limb (The trunk area, see pic. below, is supplied by a different artery than the face and upper limb).

The same pattern is seen in the cerebellum (pic below, trunk in the midline, arms and legs more lateral). Its most central part subserves trunk motion while the more lateral parts are responsible for limb movements.

As for the basal ganglia, it is said that one of the roles of that part of the brain is to position the trunk to facilitate anticipated limb movements. All of these are gray matter areas. However, even the corticospinal tracts that send messages down the spinal cord and eventually to the nerves that reach individual muscles, have one section that mainly sends messages to the trunk (anterior) while the main section (lateral) sends instructions regarding movement to the rest of the body. (See the difference in the anterior and lateral corticospinal tracts in pic. below, and that the blue tracts are much larger than the red).

So it would appear that the brain, overall, does not reserve much area for movements of the trunk, and some parts of the brain actually position the trunk in advance, to allow required limb movements to become easier. At the same time, the brain is able to fine tune a lot of specialized movements of the upper and lower limbs, which, in the case of golf, involves mainly the arms. Why then, does the “classic” swing require one to rotate the entire trunk during the back and through swings? Why does the “modern” swing expect the pelvis and hips to initiate the downswing? Of course, in the latter case, some might say that the stretched core muscles contract to produce torso rotation, so no active brain instruction is necessary. To an extent, that is true, because rotation of the trunk could be thought of as “free” (from the stretched muscles contracting forcefully). However, the modern swing also requires weight-shift towards the target, and, in addition, many people in golf believe that a “squat-jump” type movement needs to take place during the downswing, both of which require considerable voluntary – “paid for” leg-muscle action.

How is the MGS a perfect match for the design of the brain? It rotates the entire spine before the swing even begins. That is a voluntary (brain controlled movement) but there is plenty of time to get the rotation done. Then, in-swing, it uses all the “free” energy of stretched core muscles (which are stretched to a greater extent than in other swings); with greatly reduced “paid for” intentional movements of weight shift and upward torso rise, which require active muscle-work to achieve. Bottom line, it simplifies the job of the brain, so that it does not have to create fast, coordinated, intentional movements of the trunk while also co-ordinating arm motion, especially because the golf downswing only lasts 1/3rd second, at most. Why overpower the brain? Let it do what it’s designed to do best during the fast action of the swing, and complete the actions that it obviously does not prioritize, in advance!

Danny Willett and Back Injury – What are his Options?

Danny Willett and Back Injury – What are his Options?

Danny Willett is a fine British golfer and winner of the 2016 Masters’ championship. He is not yet 30 years old, and was most recently in the news because, according to a

Daily Mail (UK) article of 25 July 2017: “The L5 (disc) and the sacrum were out from the x-ray which is why it hurts when I rotate on it. I was on Voltarol all week and wasn’t doing much practice. Asked if surgery could be the answer, Willett added: ‘I don’t know. I’d do anything that helped. I don’t think it does need surgery, it’s more just getting it in line and the only thing that irritates it massively is swinging poorly.’

What should Willett do next? Take a break to let himself heal, right in the middle of the golf season? Rely on temporary healing of an injury which may recur immediately the injury causing mechanisms are repeated? Have a chiropractor dedicated to him who adjusts his spine every few holes – if indeed that works for him? Have, heaven forbid, surgery? Or consult a movement-analysis expert who can explain not just his injury but also how he might get better consistency as well as improved ball-striking through an all-encompassing assessment? Only he can decide. However, this is what one movement-analysis specialist can offer (based on an extensive education in musculoskeletal anatomy, injury mechanisms in sport, motor control and even biomechanics; see more in the “about” section of this website):

Generic and golfer-specific analysis: What are the positions and movements of the human body that would cause injury in any golfer? What are this particular golfer’s specific joint constraints that need to be taken into account while helping him make an effective, efficient and safe(r) golf swing? While specific plans would need a detailed history, posture, gait, and swing analysis, the generic aspect would apply to all golfers with similar swing mechanics.

The first order of business would be to look at the etiology of the injury (it may have been caused by other factors and only exacerbated by golf, but that is bad enough). The only “history” available is that the L5-sacrum joint of the vertebral column was “out”; there was pain upon rotation; and “massive” pain when the swing was “poor”. (A highly-researched article on back injury in golf here: https://thegolfnewsnet.com/kirankanwar/2017/04/12/golfers-lack-spine-104621/). In the absence of any further information, the first reaction should be “no backswing which separates the thoracic from the lumbar rotations”! In addition, other positions which cause greater than normal compression or shear loads at the site of injury include excessive spinal forward flexion (see pics below) and a big “crunch” factor of lateral flexion (side bend) and axial rotation during the downswing, and past impact. So that explains the mechanisms of injury during the downswing, which takes place at high speed, excessively loading the spine. What next? Look at other golfers with similar issues and use solutions they might have hit upon? For instance Jason Day in an interview some months ago said he was reducing backswing length to reduce downswing “crunch” (which was the position when he felt pain)? No! 

The most scientific solution would be to work backwards from the requirements of the downswing and impact – in this case less forward flexion and less lateral bending during downswing axial rotation. Then one should figure out set-up and backswing positions that will permit a safer downswing (not forgetting such positions must still allow the club to arrive at the ball from the inside, and at speed, to fulfill good ball-flight requirements). Generic scientific solutions would include 1. a more upright posture, 2. keeping the right (Willett is right-handed) shoulder lower than the left throughout the backswing, and 3. changing the manner in which torso rotation happens.

These latter two solutions are unique and thus unusual, but absolutely vital, and even supported by what we know from basic musculoskeletal anatomy, neuro-anatomy and motor control. As regards 2. above, why have a right shoulder that is higher than the left at the top (see pic below of lower left shoulder, ie. higher right shoulder, at the top)? It creates  a far longer range of motion for the right shoulder to have to drop down through, than if it stayed down throughout the backswing. In addition, the core muscles and largest torso rotators – the abdominal obliques – would then have a forward (towards target) instead of downward (towards the ball), line of action. Should a golf downswing make the core move down towards the ball or forwards, towards target?

As regards 3. above, did you know the brain has an area of gray matter called the basal nuclei/ganglia which send motor commands to set-up the torso so that it can be positioned to better facilitate limb movement? And that there are separate pathways for commands going to the trunk and proximal parts of limbs to travel down, than there are for messages to distal parts of limbs? That means the brain itself tends to separate the movements of the proximal (eg. pelvis) and distal (eg. arms, forearms, hands) parts of the body. Suppose we were to simplify the brain’s job by consciously positioning the body so the brain has a less complex movement to supervise?

Modern motor control theory also suggests concepts that might support such ideas. A paper (this is a must-read paper written by the postulators of the concept:                   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2965031/ ) on a fairly new concept termed the “leading joint hypothesis”, tells us that, “Unraveling the principle used by the brain to organize human movements is one of the primary goals of motor control research. The need for a principle or a control strategy is apparent when the task can be performed via many different movements, yet a single movement needs to be produced.” In addition, the authors, while explaining their hypothesis state that, “The leading role is endowed to a joint that has mechanical advantage in the limb. Because of relatively high inertia and the increased musculature of the proximal limb segment, the mechanical influence of proximal joint motion on distal joints is much higher than the influence of distal joint motion on proximal joints. For this reason, the leading joint is often the proximal joint that acts similar to a whip handle, a single wave of which can cause complex motion of the cord.” All of these concepts might be said to argue for a  trail side of the body that stays down and does not rise during the backswing, as well as a pre-swing positioning of the pelvis, through desirable torso rotation.

Incidentally, any improvement in positions and movements that reduce the potential for injury will also improve ball striking and consistency because after all, if all joints are positioned based on their design capabilities, they do not get “stuck” in the middle of other joints moving “this way and that”. All body parts are then able to act in cohesion to produce a “domino-effect” downswing, which places the least possible loads them all, and allows a smooth-flowing, without-volition, downswing.