Sunday, May 20, 2012

A Roadmap to a Hall-of-Fame Forehand - Part 6: Could Hall-of-Fame Performance be Determined by a Single Movement?

If you’ve been following our blog at all, maybe you’ve noticed that our attention is focused almost solely on what and how top players do the things they do on the tennis court. We are interested first and foremost in understanding how maximum performance is achieved by these unique individuals. Our specific aim is to identify what qualities, characteristics and attributes separate the top performers from everyone else.

In practical terms, our general approach to figure out what these incredible individuals do—and how they do it—is to seek out the differences between about those individuals who demonstrate so-called outlier performance compared to everyone else.  This approach – whether it applied to studying and understanding athletics, investment banking, aerospace engineering, or whatever the subject may be—often turns out to be the fastest way to reverse-engineer the genius of those outliers and ultimately offer everyone the opportunity to understand and then maybe integrate, at least, certain fundamental qualities of their intuitive, natural brilliance.
Very often in the elite athletics arena, the differences in the athletic movements between the most successful individuals in a given event are minute in size, form or extent, and happen on a miniscule timeframe of only a few thousandths of a second. This “quicksilver” nature of outlier performance appears to be especially true in athletic events that are based on speed and power, as the sport of tennis is today.

Therefore, detecting these types of athletic “micromoves” or “micromotion” may prove quite challenging given that they are invisible to the naked eye.
In our last post, we presented a general description of what we have come to understand is the most important phase of the topspin forehand stroke: the transition from the backswing to the forward swing or FHT. After analyzing the topspin forehand mechanics of 100s of competitive players using high-speed video, we have concluded that FHT is the most important phase of the stroke because the anatomical arrangement of the various joints of the racquet arm that is achieved during FHT appears to “lock in” how players ultimately make contact with the ball.


We also have come to conclude that there are effectively two fundamental types of FHT ---Type 1 or FHT-1 and Type 2 or FHT-2 (and, well, as of our March visit to Indian Wells, we have found clear evidence of a third distinct type of FHT, or FHT-3, but we’ll save that discussion for later).
Now, starting with this post, let’s begin a more in-depth conversation about why FHT plays such an important role in producing a Hall-of-Fame-worthy tennis topspin forehand.

And maybe the first question on your mind is:

“What exactly is the difference between FHT-1 and FHT-2?”


After studying the topspin forehand mechanics of these tennis outliers—whom we’ll define as those players who have won Grand Slam Championships in singles or players who have earned at least 5 million dollars in tournament prize money – using high-speed video, we have identified a specific micromove in the topspin forehand mechanics of players who strike the fastest—often rallying at speeds over 80 MPH—AND heaviest –consistently generating 3,000+ RPM—topspin forehands under Grand Slam/ATP match conditions.


There is no doubt that there are also many differences – subtle and obvious – in both gross movements (the movements that are visible to the naked eye) as well as in the other micromovements (those only visible at speeds of 200+ fps) in the forehand mechanics. 


So far, we’ve identified at least 30 distinct micromoves used by the outliers that are largely “missing” from the topspin forehand mechanics of the "non-outliers".
In light of all the wide variation in the movements used, even among the outlier group, we noticed that there appears to be a single, specific micromove that the fastest and heaviest forehands in the sport consistently demonstrate during the critical phase of FHT. What’s even more interesting is we began to realize that this particular micromove is missing—rather, is not used—by those players whose forehands desert them and break down under the pressure of competing for the sport’s biggest titles.
Finally, when we compared the topspin forehand mechanics of the outliers with players who are actively seeking “outlier performance”—i.e. college and junior players—we realized that the presence or absence of this micromove is the crucial characteristic that both defines as well as distinguishes between the two core types of FHT: FHT-1 and FHT-2.
Now, what exactly is this micromove that’s used by those players with the fastest and heaviest forehands in the sport?
This specific micromove is ELBOW PRONATION of the racquet arm at the very end of FHT during the fleeting moments when players initiate the forward swing to impact— aka the FFM, or “First Forward Move”. 

And, by “fleeting” we mean that FFM typically lasts a mere 3 to 5 frames at 210 fps – or a miniscule 14.3 to 23.8 milliseconds among all players we’ve studied.
Elbow Pronation of the racquet arm at the terminal stages of FHT, specifically at the very start of the FFM is the defining characteristic of the less common – but arguably more effective—type of FHT: FHT-2.
Conversely, players who place their racquet arm elbow in the opposite position –i.e.  ELBOW SUPINATION—causing the palm of their racquet hand to face upwards towards the sky is the defining characteristic of the more common type of FHT: FHT-1.
To sum it up succinctly:

Elbow PRONATION at FFM = FHT-2

Elbow SUPINATION at FFM = FHT-1
Now, let’s show you exactly what Elbow Pronation of the racquet arm at FFM looks like so you can determine which type of FHT is used by a given player. Let’s see how the players themselves achieve this important position it from different angles.
FHT-2 / FFM Elbow Pronation – Behind the Baseline View
As we mentioned in our last post, high-speed video taken from the “behind the baseline” perspective will enable you to make the most definitive determination of  the racquet elbow position—pronated or supinated—at FFM. See the examples below.  










FHT-2 / FFM Elbow Pronation – Side View

Elbow Pronation at FFM can also be readily see from the more common front view—but, maybe you’ll have to train your eye a bit before this position becomes readily apparent:















Now, what’s also interesting is that the biggest of the high-speed, lower spin (i.e. <2,000 RPM) forehands on the ATP tour (Berdych and Cilic) also demonstrate Elbow Pronation at FFM:





So, why is this position at this stage of the forehand stroke so important to maximizing spin generation, and why would even a player with a “low spin” topspin forehand use it?
We’ll address the first part of the two-part question above here, and we’ll leave the second question for another time.

The main reason why this is such a key move is because – regardless of whether or not the player “understands” the anatomy and physics behind this idea – the hand position at this stage of the forehand is the simplest way to control the angle of the racquet face in the forward swing and more importantly, at impact, given the physical construction of the human body.


And when you can control the tennis racquet during the forward swing, you’ll maximize your chances of generating far more topspin than you may have thought possible.


The “natural motion” of the racquet arm in a tennis forehand naturally causes the racquet hand to supinate – meaning the palm of the hand will open toward the sky as you swing forward to impact. Therefore, if you don’t compensate for the hand supination by intentionally pronating the hand – pointing your palm downward toward the ground – your hand will deliver the racquet face in an open position at impact.
Vic Braden pointed out this “anatomical reality” of the tennis forehand in his 1977 book, “Tennis for the Future”. There, he shows that in order to have a square, perfectly perpendicular face at impact, you have to close the racquet face by at least 30 degrees before starting the forward swing to have the racquet face square at impact (see below). This “swing geometry” is necessary to compensate for the natural—and extensive—supination of the racquet hand during the forward swing to impact.

What we have observed in today’s players who generate both high speed and high spin rates on their forehands have a severely closed racquet face – a natural product of racquet hand pronation—before they initiate their forward swing –meaning that the racquet face is tilted forward anywhere from 60 to 90 degrees—and results in a racquet face that’s closed – again, tilted forwards –anywhere between 7 to 15 degrees at impact (see below).

In other words, when players pronate their racquet hand just before they start their forward swing, their pronated racquet hand position enables them to control the natural supination of the racquet hand (and arm) during the forward swing and control the angle of the racquet face as it approaches impact.
And, it appears that that achieving this pronated position before FFM greatly reduces the amount of conscious effort on the player’s part to create – “on the fly” – the closed racquet position at impact that’s associated with maximal topspin production.
Their initial racquet hand pronation at the very beginning of the forward swing appears to naturally, perhaps automatically produce the “stroke geometry” that’s associated with a high-speed, high-spin topspin forehand.
What other benefits would racquet hand pronation at FFM deliver to the player? For example, is there perhaps a direct neuromuscular or physiological benefit to using this movement in a high-speed, high-spin topspin forehand? A deeper, and more detailed consideration of this question shows that there may be several possible neuromuscular/biomechancial benefits to incorporating this anatomical position at the FFM stage of the forehand stroke.
Let’s start this discussion by introducing the most “powerful” of these potential benefits: racquet hand pronation at FFM maximizes force production by one of the major “motors” of the forehand forward swing – the internal rotation of the rotator cuff muscles.
So, what is the relationship between racquet hand pronation at FFM and maximal force production by the rotator cuff muscles – specifically the contraction of the subscapularis muscle used to create the internal rotation of the shoulder that propels your (racquet) arm forwards to impact?
The relationship between these two movements and how it influences force production goes like this:
By pronating the racquet hand at this stage, this position prevents "premature" external rotation of the shoulder – because external rotation (“ER”) of the shoulder prior to the internal rotation (“IR”) of the shoulder enables you to tap into the force-multiplying effects of what’s called the Stretch-Shortening Cycle, or “SSC”.
For a concise explanation of this neuromuscular/biomechanical phenomenon, let’s consult this passage from Bartlett’s 2007 textbook titled “Introduction to Sports Biomechanics, 2nd Edition”:
Appendix 2.1 Universal and partially general movement (biomechanical) principles
Use of the stretch-shortening cycle of muscle contraction.
Also referred to as the use of pre-stretch; in performing many sports activities, a body segment often moves initially in the opposite direction from the one intended. This initial countermovement is often necessary simply to allow the subsequent movement to occur. Other benefits arise from the increased acceleration path, initiation of the stretch reflex, storage of elastic energy, and stretching the muscle to optimal length for forceful contraction – relating to the muscle’s length-tension curve. This principle appears to be universal for movements requiring force or speed or to minimize energy consumption.” (page 76)
In this case, ER of the shoulder is the counter-movement that facilitates as well as contributes speed and contractile forces to IR that is used to sling your racquet forward.  This pre-stretching of the muscles performing ER leads to causes an increase in the contraction force and speed of the muscles that perform IR, which therefore increases the force and speed delivered by your arm, hand and racquet to impact.
What’s critical to this force and speed maximization using the SSC of the rotator cuff muscles is the timing between the pre-stretching and the contraction of the muscles being used. Due to the neurophysiological properties of motor neurons and your skeletal – or, “voluntary” – muscles, there is a “shelf life” or time limit to the increased force production created by SSC. Muscle contraction must occur with 50 milliseconds (50 one-thousandths of one second) after the pre-stretch, otherwise you’ll lose the ability to generate increased – maximal – force by the target muscles. And, the longer the delay, the less force will be produced.
Applied to the topspin forehand, there is a 50 millisecond “window” of opportunity to produce maximal force after ER creates that pre-stretch of the IR muscles.
Next, let me point out that ER of the shoulder is also used to supinate your racquet hand. You can feel this for yourself. Hold your arm out to the side with your hand pronated - i.e. palm facing the ground. Then supinate your hand – without moving your arm – so that the palm faces the ceiling or sky. You should pay close attention to the sensation in the rotator cuff area when you do this movement. What do you notice? You will feel a tension in exactly those muscles used to produce ER.
Now, understand that by performing ER, you are simultaneously pre-stretching the muscles used for IR. In other words, racquet hand supination at any time triggers SSC in the rotator cuff musculature. With SSC triggered or “turned on”, realize that you have a 50 millisecond window to collect the reward of SSC—which is increased, if not maximal force production by the IR muscles.
Therefore, if you want to tap into the force maximizing effects of SSC in this critical group of “motor muscles” that powers your forward swing, you need to be very careful about when you trigger that particular SSC. This also explains why the sequence of the body movements – nerve firing, joint movements, muscle contraction patterns, etc.—used to execute an athletic movement such as a topspin forehand is such a critical property of any athletic movement. And it’s an especially critical factor if you’re seeking to optimize or maximize the performance – power – output of that athletic movement.
If you watch very carefully ultra slow motion video—meaning, stepping through the slow motion footage of the stroke frame-by-frame—of the forehands of one of the players (Federer, Nadal, Djokovic, et al.) shown earlier, you might notice that the first discernable sign of Elbow Supination occurs after FFM. This stage is of the stroke is pretty much the last possible moment to trigger the SSC of the shoulder and arm that slings the racquet to impact.
And, noting the limited time window to take advantage of the benefit of increased muscle contraction force delivered by SSC, doesn’t it make sense that triggering rotator cuff muscle activity to sling the racquet arm forward should occur close – as close as possible – to when maximum speed and force is needed at impact? 
The “optimization” the SSC of the rotator cuff is but one of several key SSCs that operate in a top-level topspin forehand.

Therefore, the same principles and factors that result in maximal force production—the timing and spatial (anatomical) sequencing—of the rotator cuff SSC operate and regulate these other SSCs that enhance speed and force production in the overall forehand stroke.
Now, let’s consider the other side of the coin…
What about those players who use FHT-1, the more common type of FHT all at most levels of the sport?
Players who use FHT-1 perform early supination of the elbow of their racquet arm – let’s call this characteristic, “ES” for short—as their racquet arm elbow is supinated at FFM. ES appears to have certain adverse performance as well as certain biomechanical “consequences” on the forward swing – as we’ve observed that players who use FHT-1 typically generate less topspin—often 15 to 20 percent less topspin compared with players who use FHT-2.

And, especially given the high ball speeds that players employ today at the higher levels of the sport, lower topspin rates effectively means lower levels of control over their shots.

Regardless of the performance tradeoffs we've observed, as we showed in our last post, indeed there are very, very successful tour-level players who demonstrate “Early Supination” (“ES”) of their racquet hand.

Here are some examples of those highly successful ATP/WTA players who demonstrate FHT-1 / ES of their racquet hand:



















Now, what’s interesting about all of these players who demonstrate ES of their racquet hand pictured here are no doubt ultra-successful based on the fact that every one of them has achieved an ATP/WTA Top 10, Top 5 or even Number 1 ranking, or has been a Grand Slam champion or finalist, and has earned untold millions in prize money. There is no question about their achievements.
Regardless, for every one of these players, their forehand is the stroke that their (true) rivals target in their matches because that is the stroke that tends to break down under pressure. And while it’s also true that each one of these players can also produce sublime power and precision with their forehands at times, the forehand just isn’t as consistent a weapon for them – like Gonzalez’s forehand that most would agree was extremely “streaky” in its effectiveness.
Furthermore, we’ve also observed that FHT-1 is by far the most common type of forehand transition,  and ES becomes the dominant movement as you go down the competitive ladder from the main tours and Challengers to the Futures level, college tennis, and in national/sectional junior competitors. And, based on our own observations over the years, a greater proportion of female competitive players use FHT-1 and demonstrate ES of their racquet hand relative to male competitive players.












Then, we might ask from the coaching standpoint this question:  if these players can’t use the (optimal) SSC of the shoulder to contribute to the power potential of their forward swing, how do they generate power? This highly complex subject we’ll leave for later discussion.

Now, maybe a more pressing question would be this:

Is it possible to produce the same “stroke geometry” that’s associated with a super-heavy, high speed topspin forehand without pronating the racquet hand just before or at the FFM?

Of course this is possible…  

And it’s done every day by the vast majority of tennis players out there, recreational and competitive players alike.

Even ATP and WTA pros try to achieve high speed, high spin forehands without using pronation at FFM. It’s just much harder and more complicated to achieve with the same consistency that’s required to achieve the type of forehand speed and spin performance of the top players who use racquet hand pronation at FFM.


The vast majority of tennis players hit their heaviest topspin forehands by attempting a wide variety of body movements to create the stroke geometry associated with high-speed, high-spin forehands. The commonality of the topspin-amplifying technique/movements used by the vast majority of players is that these involve consciously manipulating the racquet hand and arm during the 100 or so milliseconds before impact.

These contrived movements commonly include such movements known as: “windshield-wipering”, ” wrist action”, “wrist rolling” or “wrist flipping”, “brushing up at impact”, “reverse finishing", etc. , etc., etc..  All of these movements involve highly conscious, and often last-second, timing-intensive racquet manipulation where required stroke consistency can only be achieved with an inordinate amount of practice time that’s only really available to serious competitive players.

 Yet, these moves probably represent the most common methods for generating heavy topspin for the vast majority of recreational and competitive tennis players alike.

The reality appears to be that most players use so much conscious manipulation of the hands and arms to create the rising, closed racquet face necessary to create gobs of topspin that are required to maximize control and precision at high ball speeds (75+ MPH) . Then, consider this next performance reality where there is large variation in the speed, spin, and direction of the shots generated by your opponent/partner every time you play. The combination of these two realities of tennis leads me to conclude – on the surface – that the mastery of a heavily-spun tennis forehand for the vast majority of players requires a large amount of natural talent (motor coordination), repetition and (correct) instruction.

At face value, the cold truth may be that mastery of the precise timing required to consistently deliver the racquet face at impact in the manner that’s needed to produce all that nasty, heavy topspin may be out of reach for players who aren’t capable of ATP or collegiate performance levels. At the same time, for many players, including a surprising number of touring pros, they treat each forehand they strike as a new math problem that needs a unique solution.

Therefore, every forehand ends up feeling – and even looking – different.
We all know how talented the best tennis players, as well as the enormous amounts of time they have spent mastering the various skills they have at their disposal. So, obviously, these top talents are therefore capable of consistently executing those 80+ MPH forehands with 3,000+ RPMs of topspin with the precision and consistency they do.
In this light, does this mean that there’s necessarily a long, hard road ahead for anyone who wants to increase topspin production on their current forehand?
Not necessarily, IMHO…
You see, if you understand the “natural motion” of the racquet arm in the forward swing to impact of a tennis forehand, and combine this with a firm understanding of the “impact geometry” that’s needed to create large amounts of topspin, we can drastically reduce the number of variables to adjust (as well as the amount of practice time) if you’re seeking more topspin (and speed) on your forehand to these three essential concepts:
1)      You need to pronate the elbow of your hitting arm before starting the forward swing – to the same extent as the players pictured earlier—to compensate for the natural supination – or opening of the hand causing the palm to face skyward – of the racquet elbow /hand to ensure that you can deliver the racquet face in a closed position – i.e. racquet tilted forward—at impact.
2)      You can start to experiment with how steep or how shallow your upward swing path affects the resulting shot. The simplest way to do this is to start experimenting with how far below the impact point you start your forward swing. You might also experiment with the height at which your racquet hand finishes after impact. You may find that you produce more topspin when you shallow out your overall swing path and use a finish lower versus swinging more steeply upwards and finishing high – when the racquet hand finishes up at head-height or higher. And, you should note that this concept effectively runs counter to the “how topspin is produced” paradigm ingrained into the “stroke knowledge” of most tennis players and coaches possess.
3)      You need to learn when and how to pronate your hand – or “re-pronate” is the more appropriate description—as you accelerate your racquet through the impact zone. Elbow Pronation in the impact zone is how you can support, stabilize and maintain the forward tilt of the racquet face at impact, especially when impact is made off-center. Elbow Pronation of the racquet arm at FFM and just prior to impact creates maximum racquet speed and acceleration to maximize energy transfer to the ball. In other words, Elbow Pronation plays a crucial role in maximizing both spin production and ball speed.

These factors are all subjects we’ll certainly discuss in greater detail in the future.
In my own coaching experience, when advanced competitive players incorporate these concepts, their forehand topspin production has increased 25 to 30 percent, on average, and a few players have nearly doubled their spin rates (with the caveat that these players had low-spin forehands to start, i.e. <1,500 RPM, on average).  

And, an added benefit they achieved was this: because they increased the level of (length) control they had over their forehands due to the increased topspin they could generate, they also felt the confidence to increase the speed of their shots by 15 to 25 percent as well. Most likely, this is due to the fact that as they swung faster, they were able to maintain or actually increase their spin rates and maintained control over their shot length. Even with the increased ball speed that causes the ball to fly further, the increased spin rates prevented their shots from flying long.
Are these three concepts the “be-all and end-all” instruction for executing a high-speed, high-spin topspin forehand?
Not at all…
While these three technical concepts probably represent the core principles of “extreme topspin” production on forehands, there are still even more complex concepts, movements and techniques that can even further amplify both spin production and racquet speed –racquet speed in particular—but will require a talent level on the player end that unfortunately leaves out most of the tennis-playing population – like 95 to 99 percent of that population.
And finally, it will take a really unique knowledge and understanding of stroke mechanics on the coach/teacher end to determine the optimal order which these three fundamental, topspin-amplifying concepts are presented to a given player.
In practice, a “cookie-cutter” approach to any instruction doesn’t really exist, especially if the player is an experienced, competitive player – regardless of the level they actually play at—whether it’s junior, college, professional or veterans’ tennis. The sequence used to incorporate these adjustments are unique to each individual player not only because of the fundamental variation in each and every  player’s intrinsic physical capabilities, or “talent level”, but because of the differences in each player’s intellectual understanding about how their strokes work and even more importantly, on their attitudes toward change.
Without an attitude of (curiosity and) openness to new ideas and new methods, improvement—in general—will be difficult at best.
If you’re ready to increase the amount of topspin you can generate on your forehand - and increase the amount of control you have over your shots - why not consider integrating these three concepts into your stroke?

TTFN!

P.S. The answer to the postscript from the previous post that asked about the FHT-type used by Messrs. Federer and Djokovic is that both future Hall-of-Famers use FHT-2.

Since 2003the vast majority of Grand Slam Men's Singles Champions have used FHT-2. This represents an astonishing 35 of 37 Grand Slam Singles titles during this nearly 10-year period!

The two exceptions in this period (2003 to the present) are Andre Agassi (2003 Australian Open) and Juan Martin Del Potro (2009 US Open) - and these two players actually use a third distinctive type of FHT ("FHT-3") we've only confirmed after our visit to the desert earlier in March (as mentioned earlier).

Therefore, if we are to learn the lesson of the most recent decade of tennis history, every effort should probably be made to make sure that future Grand Slam contenders will develop a topspin forehand that employs FHT-2 (or perhaps, FHT-3)...

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6 Comments:

At 4:13 PM, Blogger Antonis said...

Excellent, Congratulations. Here is a further statement you might want to comment on: As you said, after pronating at FFM, as the racquet moves forward, the elbow supinates to contact resulting in an opening racquet face: At contact the racquet still faces down but the face is opening. When a player makes contact below the sweet spot, the racquet face bounces back and closes, resulting in a short contact time. This reduces ball - strings friction and therefore topspin. It is the opening face inertia generated by the supination during forward movement that keeps this from happening. This keeps the strings in contact with the ball for longer increasing topspin. The "repronation" is largely passive. This is necessary to minimize the strain of the forearm muscles.

 
At 12:36 AM, Blogger Nicola Formato said...

Great! This is the most useful instruction I've found.
I'm wondering if you have done the same work for backhand and serve shots.

 
At 9:35 AM, Blogger widmerpool said...

I just found this blog and now it's finished? Wish you would keep it up. Good stuff.

 
At 9:58 AM, Blogger Ahmed said...

Excellent post and valuable information.
I've watched a YouTube video explaining the top spin is mainly from pulling your arm while brushing the ball.
Reading previous posts and waiting for the coming ones.
Thanks :-)
Ahmed.

 
At 11:42 AM, Blogger Tim Prapong said...

The single best blog I have ever read on the difference between Fed/Nadal/Djoko forehands and the rest of the field. Proof why American tennis lags well behind is definitely here.

 
At 6:17 PM, Blogger Ljubomir Galovic said...

This is by far the best analysis I saw!!! Is there any chance that you make something like this for the backhand.

Thank you for your effort!!! It head been great help!

 

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