The High-Tech Swing

Article. The High-Tech Swing

POLO !Magazine sets out to unlock the mysterv, of 10-goal strokeswing state-of-the-art technology


Published on Wednesday, May 1, 1985 by Ami Skinil

Frame by frame, the high-speed film is projected on an electronic screen and each reference point is touched with an electronic pen connected to a computer. With lines, the computer connects the points to create stick

figures. Although all three men were mounted when the film was made, we suhsequently removed the horses from the computer image in order to reduce confusion.



POLO !Magazine sets out to unlock the mysterv, of 10-goal strokeswing state-of-the-art technology. A nivsteii- no more. �-e oiler freshpromise to aII who want to improve.

By:lmi Skinil.`kp

Thankful he Ire who is blessed with Gcxl’s gifts to athletes – remarkable coordination, quick reflexes and the ability to perform well without really knowing why. Still. when you can enhance (rtxl’s gifts with scientific insights, the results can be even more astound

ing. For those of us whose athletic talents arc less distinguished, however, the same scientilic insight, cut play a much greater role. In Tact, much of the credit for the improved performance in various athletic endeavors over the last decades is directly due to science –

whether through better understanding of tht hiomcchanics of sports or of exercise phvsiul ogy. By contrast, over the same period, race horses have not shown the same level of iun provement because the sport has tradition ally paid little attention to what mcxlert

\t \V I Oft”


the difference is the quality”

The action of the game and the ponies that make it are emphasized in these striking watercolors by world famous horse painter Sam Savitt. Official artist for the United States Equestrian Team, Savitt has authored more than 15 books and illustrated another 150 books about horses. He is known worldwide for his horse charts and is listed in Who’s Who for outstanding achievements in his field.





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A side view of the same sequences, every fourth frame. Ccourell’s horse traveled somewhat slower than the others, but his stroke also lacked the snap. Compare the three hitters’ waist angle, the angle of their mallet at the stretched-arm position and the elbow position in the final phase of the

stroke. Also note the ball. The first image was shot prior to impact and the other two afterward. In Gunnell’s case the mallet head traveled faster than the ball even after impact.

hitherto Ha aicl in teaching and improving the polo stroke.

‘Th(- research group we selected was the world-renowned Coto Research Center (see sidebar oil page 511). %It se most recent accomplishnwnt was the sfwctacular lx�rfi)rmance of the silver-tiietial l*.S. wontc�n’s vollcvball team at the Los Angeles Olympics. The sul)jec�t .sts chce,cn to rcprc’scill the best in Ix)lo hittitt,g were� Mono) Graciela (111) and Po lger cl-l,Ili�ndi (8;. The one for the lowgoal stroke was Alan C:onnell. We didn’t want to select a complete novice but rather a player \%-hid be nxo-e typical in ability of the largest segment (11,111C playing poplilat loll. At I goal and in)proying, Connell offered us that.

The first stage of’ tile study look place at Palm React) Polo & Country (:tub. Three high-speed nuavie cameras were Ixasitioned at three different locations and carelitlh calibrated so that data later ft- I into the computer would generate three-dimensional perspectives. ‘I’ll(- cameras recorded 100 flames per sccuncl: Ihtts we could learn what happened at intervals of one one-Iutndredth ofa second.

Dining the second step, the edited film

was projected 1411011′ by Marie nn a large electronic screen. Twenty-roe points on cacti frame were touched with an electronic pelt. which the computer sttbse�yucntIv recorded as the relative position of, each (II* these Ixtints, c.g. right shoulder, right ellx)w, right wrist�

right hand. mallet head and sea ()it (Fig. I ). FIGURE 6

When this lung and tedious (hurt had been cu)I)leteel. the computer began crouching and reams of difTercmt cross-tabulated charts were generated accorcfitig to the variables Stipulated..-\lso, by connecting the appropriate reference points with lines, the computer can generate stick ligttres that (-.tit be viewed brunt any angle – even above and below. The final step, of course, is a painstaking analysis of the results. Those ptcsent&d here are fi)r the ell-side f reward smoke. Reboots on the other strokes will follow in liture isslucs.

First, some general observations. Our

fastest hall traveled at about 84 miles pe�r, loom-, and at a gallop, with more adrcnalin (lowing and the ball in nuatican, it will travel

even laster. Still, the mallet, dude conclusively, is not a very cllicie�nt instrument. The relatively large size of the hall and its lack of resilience mean that tile knee which propels the ball will not translate into the same relative velocity as that of’a gulf or tennis ball – ill those instances the ball will move faster titan the objects that propel theist, whereas in Ixtlu the ball travels considerably slower. That 81, mph hall was struck by a mallet traveling it 131 ntph. There is, therefio’t�. rcxan) for improvement in a polo mallet II’ greater efficiency is in the interest elf liltg’


:\mother consistent observation is the iota tiye uninmp ortance of ill(- lower part ol” the boxly. III every rather stick-and-ball or objectthrowin g sport, the lion’s share of the power generated comes front the legs and torso. Not only dtx’, the ground act as a firm counterforce to the muscular effort. but the entire mass of the Ixxly contributes to the force generated while cart-fill management of the legs’ motion further maximizes the force of the impact or release. In lxalo, our bioniechattical analysis revealed. the upper lxxly does nearby all the work and, sl)ecilically, the most critical pat is the right shoulder.

Lastly, the various chat is clearly revealed how much the horse complicates the task of hitting the ball. In order to isolate some ofthe

An instant before impact. Note the straight arm. With the forward movement of the horse, the hall is almost under the player.




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These charts show the resultant velocities of the four critical points of the body: right hand, elbow, wrist and shoulder. The peaks represent higher velocities and 0.0 on the X axis represents the point of impact. Note how smooth Gracida’s motions are and how much more erratic (in the eyes of the computer, at least) Connell’s are. ElEffendi’s motions are also very rhythmic except for his right shoulder, which he uses especially as he brings his arm down.

MAY, 1985

The other thing to look for is the changing velocity of the arm along the four points in relation to the point of impact. In the cases of Gracida and el-Effendi there is a rapid deceleration before impact, while Connell’s hand doesn’t slow until impact The curves show a slight deceleration in the elbow and wrist, but that occurs only because of the accelerating hand, causing a net effect of no acceleration at all.

variables and improve the basic hitting techniques, structured and purixaseful work on a stationary horse is a must.

Let’s look at our two good hitters first and see what goes into a good hit. At a canter, a horse moves at a speed of l0 to 12 miles per hour. From the instant a player begins to wind up until impact, the elapsed time is only about one second, a shorter period than the casual observer would expect. The time frame in which the arm is stretched above the head (Fig. 4) and the mallet motionless (except for the speed of the horse) is extended or shortened in order to allow for impact with the ball at the correct position. Obviously, striking too early or too late will result in a deficient hit. This motion of stretching one’s arm overhead at about 45 degrees to the line of the shoulders with the mallet’5t a right angle to the arm is not just style – it is the very ltundation for a gcxxl oft-side stroke. KAY leaning forward at the waist, the shoulder is cocked as far back as it will go; (corn that Ix)sition the power of the swing begins. The elbow remains locked as the arm accelerates from the shoulder, and it doesn’t bend until the instant following impact. Although the shoulders turn to the right during the windup, they are barely turned at the point of impact. Rather, to further reinforce the strong shoulder notion, the right shouldet rotates forward for additional body velocity and mass.

As the arm accelerates, you tray think, it reaches its maximum speed at the point of impact. Wrong. In the case of the good hitters, the ann reaches maximum velocity when it’s about in the position seen in Figure 5 and then, believe it or not, the arm begins to slow down. The head of the mallet, on the other hand, because of the deceleration of the ann, rapidly accelerates until the point of impact. TI he deceleration of the arm is slight and probably not even perceptible to a hitter (Gracida wasn’t aware of it), but it’s the second secret to good hitting.

In numbers, here is how Gracida’s stroke looks: His wrist reached a maximum velocity of 29 mph and at the same point the mallet head traveled at 54 mph (a point on the cir cumference of a circle travels faster than a point closer to its center). At impact his wrist had slowed to 24 mph – a reduction of I i percent in velocity – while the mallet heat reached a velocity of 134 mph – a 148 per cent increase from the instant his arm b egat to slow down.

I’d like to dwell on this phenomenon for i moment to underline its importance, mon proof of which we’ll see when we ex:unina Connell’s stroke, which doesn’t exhibit thi: critical pattern.

An image or two first. You stand by the river with your fishing red, you bring the nx back, rapidly throw it forward and thct

0 -heck your motion. I Look and sinker hays thus been propelled to cover the desired dis tance. The mallet is not unlike a fishing rod Or, when you are traveling in a car and yot put your fiat on the brake, the car slow: down but your body wants to continue mov ing forward. The physical principle of inertia




For the athlete, one special California facility works nothing less than technotragic. When lie has seemingly reached the pinnacle of’ “perfection,” where does he turn’ Fortunately, to the Coto Research Center (CRC), which has become an Oz of sorts fur athletes who have exhausted all conventional means of improving their performances. Comprising almost 8.000 square feet of laboratories with highly sophisticated computer equipment, exercise and workout areas and support facilities, CRC is the dreamchild of two men – Dr. Gideon Ariel and Vic Braden – who have worked together since 1975.

The founders’ primary goal is the optimization of eflicient human movement in all phases of athletic and industrial performance as well as in daily living. CRC’s various study results have been applied to sport and non-sport activities as well as product areas such as physical rehabilitation and industry.

Dr. Arict, the originator of computerized bioniechanical analysis, defines their work as “science serving industry, sports and human performance.” Over the years lie has worked with athletes such as Jimmy Connors, the Dallas Cowboys. world-champion discus thrower Mac Wilkins and now polio players.

Vie Braden is a well-known sports psychologist. He directs the high-speed film sessions used in the bionechanical analyses in addition to developing innovative and educational audiovisual teaching

is what is in play here: a body in motion tends to stay in motion while a beefy at rest tends to stay at rest. Also, any acceleration (or deceleration) creates force in the opposite direction. Physics then determines that in order to maximize force and utilize the full benefit of the accelerating object’s mass, there is a kind of snap at the point of impact so that the force is released at and not through it. Think of a karate chop. Even boxers, it’s been found, pull their punches at the instant before impact so that their entire body mass participates in the blow, as opposed to only their arm-a kind ofa massive snap.

If a polo mallet were made of an absolately stiff material, the deceleration of the arm would begin much later, but given its great flexibility (even a stiffmallet is very flexible), the deceleration process must start earlier. Much like a fishing rod where the backward curve snaps forward in the casting pro

aids. I lis films and writings on tennis have also gained him international acclaim.

Ariel and Braden are joined by Dr. AI. Ann Penny, CRC’s Director of Research, who has served as president ofCornpute�rized Biomechanical Analysis since its formation in 1971. As coordinator of all incoming research projects, Penny supervises the crucial digitizing process.

Were it not for the Coto Research Center, the hand might still be quicker than the eye…. 0


In the uncharted waters of polo’s corporate sponsorships, one might say that the sport’s sponsor ship has come in. It is embodied in a fleet of luxury liners known as Royal Viking Line. And in a gesture of gocxhwill, the San Francisco-based cruise line has largely underwritten the cost of our high-speed analysis of the polo swing.

Ever since the clays when “posh” became an acronym for an elegant port-outstarboard-home cruise, the bows of Royal Viking’s vessels have cut the waves toward 132 ports-of-call in exotic locations. Royal Viking’s world-class service, exquisite accommodations and tempting cuisine have hit its competitors amidships. That same sort of adventuresome spirit marks its relatively recent involvement in polo through best-playing Irony awards and tournament sponsorship.

Notes the cruise line’s John Richards. Vice President of Marketing and Planning, “We are pleased and excited with the opportunity to become affiliated with the sport of polo, since many of its fans have enjoyed our fide cruise ships and hopefully will do so in the future.” 0

cess, the curve in a mallet cane becomes reversed in the hitting process. ‘This reverse cure is as true of a golf club as it is a polo mallet.

A closer kook at a few other details is highly revealing. For the good hitters, their knees serve� as a firm base of support: there is especially little motion in the right knee area. At the outset, the tipper body leans a bit behind the vertical but gradually bends forward to give more momentum to the stroke. Also, bending at the waist allows the hitter’s arm to be stretched higher in the cocked phase prior to final acceleration. The wrist remains frilly flexed just until the point where the arm is parallel to the ground and then begins to rotate counterclockwise and close As the

This is the point in Connell’s stroke where the good hitters begin to decelerate. Note the bent elbow.

arm begins to decelerate, the wrist close more quickly, finishing on a straight line ai

the point of impact. This motion, however. emanates throughout Gar the shoulder.

Befure we proceed to examine Connelfs stroke, some comparisons between Gracida and el-Ellendi are worth noting. The. maxiinutni velocity of el-IJlendi’s hand reached 3′, mph while Gracida’s was only 29 nrph, yet Gracida’s mallet head reached a velocity of

134 mph and cl-Eflendi’s only 105 mph – a seeming paradox. The answer lies in that critical phase of ann deceleration. Gracida’s rate of deceleration was more rapid, thus the head of’ his mallet snapped f onward faster, reaching a higher velocity. III fact, his deceleration was rapid enough and his mallet perhaps more flexible to slow the head with the arm for about three-hundredths of a second before the rapid acceleration of the head commenced (from 54 mph to 134 mph in seven hundredths of a second).

Now comes the next surprise. In spite of the different mallet head velocities, Gracida’s and el-ElIendi’s ball reached almost the same speed: 81 mph. We have no definitive explanation because some of the variables are by chance. (For example, although the (rajectoties of die balls were about the same, done mallet grazed the ground more closely than the other, a good bit of the force could have been lost right there.) As far as bionechanical components. the weight of the mallet is. of course, part of the equation. Force is equal to mass times acceleration, and el-Efl6idi’s mallet was heavier. Gracida’s mallet weighed about 16.5 ounces while el-Ellendi’s was closer to 18. Also, cl-Elfendi makes greater use of’his right shoulder (Fig. 8), thus adding to the body mass behind the mallet. When the velocity curves of the arm points are contpared, Gracida’s motion is exceedingly snnoodi, while el-Eflendi’s is snrcxith with the exception of the busy right shoulder, which at times works almost independently of the rest of his arm.

Watching Alan Connell hit the ball, his form looks pretty good. He hits the ball squarely, though not with the same “authority” as the other two. Upon examining the sequence of stick ligurrs representing his stroke (Fig. 3). his subtle shortcomings become ill)





If you drop a plumb line from Gracida’s right shoulder it will intersect his center of gravity. The ball at impact will not be far from this line, either. Gracida’s head, as the broken line shows, is over his toes.

parent. His horse travels a hit slower but lie also starts his sv~itrg earlier. Council lacks the crispness of the high-goal hitters; lie doesn’t make as cllcctive rise of his tipper body, while his lower body and legs don’t provide him with a sufficiently stable support.

Before we proceed to the velocity and displacement charts, let’s take a closer look at the stick figures. Compare Gracida and C:onnell in Figures 10 and 11. l firing the critical stretched-arts phase, Connell’s center of gravity is behind the vertical, causing him to be off balance. Of course, this Means that his upper body cannot enhance the stroke – it actually hinders it. Draw a straight line fi’onr the top of’the short line above the stick figure (it represents the fiorehead), and you’ll see that Gracida’s face is over his tens while Connell’s is well behind with only the horse’s back to support hire. As mentioncel earlier,


Connell’s right shoulder isn’t over his center of gravity. Thus he is deprived of the full benefit of balance and the power of his body. Ibis head is

over his toes.

failure to bend at the waist, even without getting out of the saddle, compromises a player’s ability to stretch his shoulder and arm up to the maximum cocked position.

Examining the individual stick figures (Figs. 12 and 13) we can learn still more. Connell’s elbow plays too much of a role. Even at the stretched position it is bent and bends still more as he accelerates his area toward impact.

“lucre are two enormously negative consequences to the bent elbow, and the greater the bend the worse they arc. The first is that the bent elbow breaks the transnussiorr of power from the all-important right shoulder, resulting in a stroke in which the right forearm takes over front the shoulder in order to generate enough velocity. That, of course, requires a greater muscular effort front smaller muscles with less support, in addition to the fact that the principles of physics are not actualized to their fullest advantage. The other negative consequence of the bent elbow is that it forces the wrist to compensate for the bend, creating a strain in the joint. When the flex of the wrist reaches its limit, the mallet may still not he in an optimal position for impact. In other words, if the elbow is bent too far and the wrist is flexed to the limit, the mallet head will point forward.

Examining the charts, we see that Connell also falls short on the second secret weapon of the good hitter (the first being the use of the

At the point of contact, Connell’s elbow is bent, as is his wrist, while the ball is struck too far forward. These are common shortcomings of low-goal players.

right shoulder). I refer, of course, to the deceleration of the arm and the resulting snap of the mallet. You remember that Gracida’s arm or, more correctly, his hand, reached a maximum velocity of 29 niph. Well, Connell’s reached a slightly higher speed yet his mallet head reached a top speed of only 74 mph compared to Gracida’s 134 nrph. His ball, it follows, also traveled slower – 47 mph versus 84 niph. Due to several ineflicicncies, if you look carefully at Figure 3 you’ll also see that after impact the mallet head was traveling faster than the ball.

Going hack to the speed of the arm, what the data reveal is that at the point at which the good hitters begin to slow their arms down (Fig. 12) Connell’s continued_ to aceelcrate until the point of impact and then slowed down. Without checking the arm’s motion (remember the fishing rod), the mallet will not snap forward and, furthermore, clue to the cane’s flexibility, the head will tail the imaginary line extended from the hand, disrupt the tuning and may chive the ball into the ground. (See Mel Bristow’s “The Science of Hitting,” POLO, May 1982.)

The deceleration of the arm is slight, and its timing and degree are functions of the flexibility of the cane and, to a lesser extent, the weight of the mallet head. This slowing down not only increases the velocity of the head but also results in better control as die arm stabilizes without the strain of acceleration. Trial and error will be required to master the skill, with a stationary horse being the correct tool. Needless to say, a periodic analysis such as we perfconned on our three subjects would be the ultimate way to optimize performance, but more on that in the future.

A few final observations. A longer mallet will drive the ball farther, as will a heavier mallet head. However, a heavier head will he harder on the wrist, especially when dribbling. A stiff mallet will always afford you better control, and the heavier the head, the stiller the cane should be. Tire ball should not be hit in front of the horse as is offal advised but rather as close to underneath the hitter’s direct center of gravity as possible.

When striking the ball. hit it, don’t hit through it. This may help the deceleration process. Another way of looking at it is to think of the relationship between a hammer and a nail – think of the ball as the nail. The follow-through is not really a part of the same motion but an extension of it. Stretching the arm tip could be aided by consciously reaching for die sky and extending the arm to its maximum.

Here you are, wiser than you were half an hour ago and probably bewildered, thinking of how to teach the body what the mind now knows. What’s our challenge, too. After we share with you the analyses of the other strokes, we’ll work toward developing a complete manual. It will require, however, life’s two most scarce resources: moncv and time. The project is nonetheless exciting and we hope that some of our enthusiasts is rubbing off on you, too. 0


FIGURE 13 MAY, 1985



A frontal view of the three players through the stick-figure representation. Also note their lack of mobility in the right knee and thigh and the line Every fourth frame was used so that the elapsed time between each between their shoulder and hip. Connell, on the other hand, is far less impression is about one twentieth of a second. Note how far the high- steady.

goalers lean out and pbserve especially the evenness of Gracida’s stroke.

science can contribute.

The better 1×010 athlete, it’s safe to say, has improved over cute, if only because knowledge acquired through subjective experimentation has then been emulated by others and every player’s performance has risen a notch. But ask live world-class players about the subtleties of their skills and you’re likely to hear five different answers about something that all du equally well. Now consider the disadvantage at which new players find thenlselves when trying t0 master 0nc of the most dillicult sports man could invent they have nothing but crude 0bscrx-aItoils and meta

phors ill their learning arsenal. A second-rate tennis pro call teach a be-,glmler More tCtlllis in a month than a first-rate polo coach could in six. The reason is simple. The tennis coach is backed by the well-researchecl and -documented Ixxiv of knowledge in his sport. It is ill an ellirt to bring the sank advantage to polo that this project was undertaken. Right tip front, though. let’s acknowledge that polo is comprised of several unrelated skills: it’s a stick-and-ball game like *tennis, ,golf or, Cr0quet: it’s a trawl endeavor like basketball or soccer: it’s a horse sport like racing or junlping: and it’s a high-speed contest like racing. Each of the required skills poses a separate challenge but, as with otltet’ things ill life, a chain is only as good as its weakest link. 1f your weakest link is hitting, or if it could be strengthened, then read on. Read on, too. if you’re at all curious abut the polo stroke and the bionlecha tics ofits many motions.

The task we set out to accomplish was a better understanding of the basic polo strokes: what makes for a good stroke and why a lesser uric is deficient. Indeed, hitting a polo ball cannot be removed front the manon-horse context nor isolated fi-onl actual game conditions, but first steps ought to be small ones and we decided to foots on the

Memo Gracida in the arm-cocked position. Note the shoulder and arm creating a straight line. At about 45 degi ees to the ground, the mallet is at a right angle to the arm, the elbow straight, shoulders turned from the hips and the body

bent at the waist.


This is the point where the arm begins to decelerate. From this point until impact, less than a tenth of a second will elapse.

lour basic strokes performed on a horse cantering to%vard a stationary ball. As we researched the subject and the prulcssiurlal resources available for such an undertaking, we discovered that the costs would exceed the magazine’s means. To our delight, Royal Viking Line agreed to undenyrite the mayor portion of the study and additional Iitnds were prtyided by Alan ( :onnell … \\,e are grateful to both. t’ncluestionably, this pilot studs- is the cunu’t’,touc for at new IsKs Of knowledee that will do more than anythinn!