where'd the bent arm come from anyway?

[Guest]

Has anyone ever asked why tennis players, coaches, and teaching pros think a bent arm is a rational way to hit a tennis ball?

Look at other sports and neighborhoods and how it has been known for decades and taught at all levels, that the extension of the arm at the shoulder all the way to the wrist/hand completes the natural biomechanical motion of hurling or hitting an object. Javelin, discus, football, baseball, hockey, golf, throwing rocks at cars or cats, the list goes on and on of sports where they've known for decades... and our tennis friends are still confused. (See attached images)

Any kid that grew up throwing rocks, dirt clods, or a baseball knows that you just naturally extend to the point of release. So why is it that tennis players got the bright idea that in order to hit harder we have to shorten our arm and muscles.

And then a couple of guys come along recently that look like they are dragging a sack of potatoes with their "straight arm" forehand, they have a couple of good weeks of tennis and tennis enthusiasts wonder if that is the next evolution.

I really would like some help in understanding how this bizarre phenomenon came about in tennis only. Was it Jim Courier? He sure drug his arm through the hitting area like he was pulling a piano behind him.

I think it all came about because tennis players came to decide after over 100 years that it was okay to actually explode with all of their might into a ball (novel concept since athletes had been doing that forever already) but since tennis players have such limiting boundaries in which they can hit (the court), they didn't know how to trust their new found athleticism to not hurl the ball into the stands and they didn't understand how to perfectly align their bodies to get an extended contact over and over, so they evolved into a guiding motion.

Maybe the whole white long pants and skirts thing just got tennis off to a very very very slow beginning of confusion as to whether this was a sport or not. I guess it doesn't really matter...does it?

[johnyandell]

Uh, again as we've discussed a few times, it's not a coaches' conspiracy. Showing video of other sports, including throwing dirt clods, is interesting but probably irrelevant.

One point overlooked is that Federer himself hits about 1/3 of his forehands double bend, and Nadal does it on a percentage.

The reason players do it is that it works for them. As you quoted the site--actually it was something I said--coaches follow players.

Sampras, Agassi, Djokovic, Del Potro, Federer, Berdych, Soderling, Murray, Jo Willie--to mention just a small number who all use this structure with huge forehands.

I'm not sure how you can call it bizarre when it's the overwhelming norm. You have certain feelings but is that right to impose on the entire tennis world? The answer is? And again maybe it is the future--and maybe not. If you really want to have credibility you'll have to explain how the average player should somehow have a more "advanced" technique used by only a few elite pro players.

[uspta990770809]

Is the arm the real lever arm?

Carrerakent,
I have seen bits and pieces of many of your responses on various threads the last couple of weeks and I certainly haven't seen them all, but the general theory I get is at least part of your teaching approach (I don't want to say system because I think you would jump all over that limiting your students) is that you should use whatever leverage you have and take advantage of the increased velocity a straight arm gives the racket head. I've seen the parts about the right contact point and athletic moves, but in general, I get the sense you are saying anyone would be a fool to try to use a bent-arm shorter lever arm to hit the ball if he could possibly use the full length of his arm. But if that were the case, wouldn't we all have gravitated to the extended length rackets that were introduced a few years ago? The serve is different because you have the ball in your hand, but because of pronation, we don't even hit that with a truly "straight" arm from the shoulder. But players are definitely getting taller in the pro ranks. But I digress. Let's stay with the forehand.

My belief is that tennis is and always has been defined by C.A.P.: Consistency, Accuracy and Power. The more consistent player will always win. The more accurate player takes his opponents consistency away from him by forcing him to play from positions in which he loses his consistency (i.e. on the run). The more powerful player wins by forcing the more consistent player to play at a speed at which he is no longer more consistent. As a result, tennis (as much as it has become a game of power in recent years) is not simply a game of power. However, spin and racket technology has equalized consistency to a large degree to the point where accuracy and power have become more important than ever before. This is, at least, my belief.

But coming back to the power generated by the longer lever arm and arc of the straight arm, (and I need some help from the biomechanists here) isn't the actual lever arm the imaginary lever arm from the contact point to the axis about which this motion is rotating. Therefore it is not as simple as the straight arm is the most powerful position to hit the ball. Before we get to the fundamental question of diminishing returns on an ever widening and increasing arc and lever arm in terms of reduced accuracy and consistency (or a heavier racquet for that matter), there is a question of whether the shoulders are part of the line from contact point to the center axis of rotation of the swing. I don't know the answer. I'm trying to propose it is not even as simple as straight arm vs bent arm. On the one-handed backhand, you could argue a straight line from the hitting shoulder where the axis of rotation is located (most of the time). But on the forehand, the hitting shoulder is the back shoulder most of the time and only gets into the line of the lever arm right at contact. You could visualize an axis of rotation through the left shoulder/hip/foot for a right hander hitting a square stance forehand with a straight arm, but we do not actually hit the ball with a truly circular motion around that axis like a hammer thrower. We generate racket head speed gradually with the assistance of a gravity drop (no charge from the cosmos!), accelerating from what I think you call the "sweet spot" behind the ball. While the body can only generate forces with torques, the forces that we create to actually hit the ball are very briefly linear. in fact, the racket touches the ball for a few inches on a 60 mph shot (88 fps x 1/250 sec x 12 in/ft). If we were truly moving the racket in an arc, consistency and accuracy would be impossible. Instead, we try to create a hitting "zone" which is probably much greater than 3 or 4 inches so that we have some margin of error and can be somewhat consistent and accurate. Because of this constraint, simply hitting at the longest possible lever arm position with a straight arm would seem to be too difficult a goal. Nice for creatures from another galaxy like Nadal and Federer (you knew that, right?!), but a little too challenging for the rest of us. On the other hand, the human ability to coordinate things is truly otherworldly and you say you are having great success with your methodology with even 80 year olds. But I feel when the ball starts to move around at the speed of world class shots, you have to be able to adapt and a "bent-arm" configuration gives you the most flexibility and ability to compensate for incomplete (not necessarily poor) footwork. And if the lever arm is actually to the axis of rotation, how much do you actually give up in power if it means you are able to keep the racket moving along that 4 inches of contact zone in a straight line delivering power to the ball the whole way (Brian, am I wrong here? Is all the power done in the first 2 milliseconds? I hope you will chime in.) In fact, I would question whether in even a "straight-arm" forehand, whether that arm is part of the "effective lever arm" from the contact point to the center axis of rotation or if the racket and hitting arm are actually parts of a triangular structure that is created by the shoulders, the hitting arm and the racket, and the imaginary "effective lever arm". My vocabulary may be way off. I would appreciate any help from you biomechanists out there. My background as and engineering school graduate and a chiropractor gives me a little bit of technical understanding, but I am no biomechanist; mostly just a struggling tennis pro dealing with a few very talented kids and a lot more people who are just normally talented.

That's enough. Hope that gets a little bit of a discussion started.
don

[oliensis]

Don,
Well put.
There are fulcrums and complexities in the kinetic chain that make it complex as hell.

Would the longest whip give you the biggest snap? (Some towels are too big to snap effectively.)

Do you hammer a nail with a straight arm? Why not?
Why is a 9 iron shorter than a driver?
Why don't pros play with 29" rackets if a longer lever is optimal?
Why don't baseball players hit with 41" bats and stand as far from home plate as possible?

Here's Federer hitting a mid-court forehand where he clearly had plenty of time to set up, move to the ball (several steps) and rip it with whatever stroke he wanted:

http://www.tennisplayer.net/members/strokearchive/pro_men/rogerfederer/rogerfederer_forehand/rogerfederer_fh_short/rogerfederer_fh_short.html?FedererFHShortSide1.mov

Looks like a modest double bend. Why not straight arm? Maybe because, given that he's rolling the racket over the ball and driving either inside in or a little bit cross court, he's using the elbow as a fulcrum, to some extent, from which he is rolling the stroke over in order to generate the particular direction and spin he's going for.

Of course, you want to use the longest lever you can within the parameters of the shot you're trying to hit, but, only up to a point....Watch this video:

The commentator is talking about similar issues for baseball swings. He's discussing the lead arm. But look at the rear arm. A lot of damn good hitters are hitting the baseball (which swing putatively should have extended arms) with double bend structure in rear arm (analagous to forehand).

http://www.youtube.com/watch?v=vS3HTHXspmk&feature=related

The difference in the length of the lever between a straight-arm and double-bend forehand may be between 1 and 3 inches. That difference is not inconsequential, but is often outweighed by numerous other factors in reality.

Of course, setting up for the ball with good distance, and keen awareness of a good contact point are very important...probably more important than the specifics of stroke mechanics in many ways.

[oliensis]

Here's another video from the same source:

http://www.youtube.com/watch?v=98mVxe1lBKU

If you don't want to wach the whole 5:47 video on batting, skip ahead to about 4:50 and let it run. The commentator addresses the myth of "extending the arms" in a baseball swing.

David Wright, David Ortiz, Ken Griffey Jr, etc., all hitting a BASEBALL w/ a double bend in rear arm. Pretty good power on all of them. Go figure!

[carrerakent]

Don,
Well put.
There are fulcrums and complexities in the kinetic chain that make it complex as hell.

Would the longest whip give you the biggest snap? (Some towels are too big to snap effectively.)

Do you hammer a nail with a straight arm? Why not?
Why is a 9 iron shorter than a driver?
Why don't pros play with 29" rackets if a longer lever is optimal?
Why don't baseball players hit with 41" bats and stand as far from home plate as possible?

Here's Federer hitting a mid-court forehand where he clearly had plenty of time to set up, move to the ball (several steps) and rip it with whatever stroke he wanted:

http://www.tennisplayer.net/members/strokearchive/pro_men/rogerfederer/rogerfederer_forehand/rogerfederer_fh_short/rogerfederer_fh_short.html?FedererFHShortSide1.mov

Looks like a modest double bend. Why not straight arm? Maybe because, given that he's rolling the racket over the ball and driving either inside in or a little bit cross court, he's using the elbow as a fulcrum, to some extent, from which he is rolling the stroke over in order to generate the particular direction and spin he's going for.

Of course, you want to use the longest lever you can within the parameters of the shot you're trying to hit, but, only up to a point....Watch this video:

The commentator is talking about similar issues for baseball swings. He's discussing the lead arm. But look at the rear arm. A lot of damn good hitters are hitting the baseball (which swing putatively should have extended arms) with double bend structure in rear arm (analagous to forehand).

http://www.youtube.com/watch?v=vS3HTHXspmk&feature=related

The difference in the length of the lever between a straight-arm and double-bend forehand may be between 1 and 3 inches. That difference is not inconsequential, but is often outweighed by numerous other factors in reality.

Of course, setting up for the ball with good distance, and keen awareness of a good contact point are very important...probably more important than the specifics of stroke mechanics in many ways.

Mr. O, I love it. You gave me a video example of exactly what I needed. First of all if you call that a double bent then you are on drugs and seeing things, secondly, notice how his right leg and hip drop back...why? because at the last second he realizes he is too close to the ball and if he had kept his hip flowing through as usual he would have had to bend the arm considerably to make good contact like all of the other pros do. This is an example of Federers genius...he's far superior than all of the other players in history of his body, the ball, and how to adapt at the last second to maximize his potential. In your example, I agree he rolls the forearm hand at the last second...again, i believe this is because of less than optimum setup.

As for double bend vs. "extended" not straight arm measurement: I just got up against the wall and measured the tip of my racket during an extreme double bend and the fully relaxed "extended arm. the difference for me, a short 5'8" in. dude is 15 3/4 inches. (that would be max) If 1 to 3 inches is worthy of your consideration, what about 12-15? How much less force does one have to exert to hit the same power or spin? Now that force being reduced equals what: GREATER CONTROL! wallah, we are getting somewhere!

The fully loose and free extension I talk about begins at the shoulder and ends with the hand. Look at Agassi hit a double bend with his elbow tucked in and compare to Federer's extended forehand. Probably more than my 15 inches difference! Many of you guys are stuck inside the box in your understanding of the extended arm because you keep thinking about and referring to a straight arm forehand. My guess is that none of you have ever hit a Federer like forehand. Until you are able to make the transition to that kind of extension and "whip", you likely will keep assuming that just straightening out the arm is the sum of the differences I am talking about. At least that is what I have no choice but to assume based on Yandell's and your and other's responses.

For the life of me I keep trying to explain that loose natural extension is my method of madness. Sure lots of baseball players have a bent arm in back...my point is in that all of those athletic examples, the athlete is attempting to fully extend all the way to contact. On the other hand, all of the double bend forehand hitters I know of shorten their arm as soon as it starts forward and it often continues to shorten until contact.

Your questions seem to be good ones regarding longer objects and distances, but your examples are about something (towel, whip, arms) that get longer until contact...not shorter. right? Sure there is a point of diminishing returns on longer rackets, bats, etc. but again that isn't the point. the point is BEING FAR ENOUGH FROM THE BALL TO ALLOW NATURAL MUSCULAR ELONGATION SO THAT THE KINETIC CHAIN ISN'T DIMINISHED AND RACKET HEAD SPEED SLOWED...plus, it's much harder to duplicate multiples of degrees of bent compared to full extension resulting in "straight".

Thanks for your discussion.

[carrerakent]

Mr. O,

BTW, many of those baseball batter's in the video are yanking their elbows in to make up for a ball that's inside on them. But still, I see the desire of extension in the rear arm in every example except where they are pulling into hope for contact with the meat of the bat.

[jperedo]

leverage

imo, the purpose of the arm extension goes beyond creating the extra leverage. My theory is it aids the hip with passive external rotation of the upper arm. Watch the timing, especially on short balls.

Fed, Verdasco, Nadal all wait until the hip rotation is already initiated before fully straightening the arm. Usually extension is initiated at around the bounce of the ball. If it was strictly a leverage aiding mechanism, it make would make way more sense from a timing perspective to just run around with their arms fully extended.

[uspta146749877]

A video to support

imo, the purpose of the arm extension goes beyond creating the extra leverage. My theory is it aids the hip with passive external rotation of the upper arm. Watch the timing, especially on short balls.

Fed, Verdasco, Nadal all wait until the hip rotation is already initiated before fully straightening the arm. Usually extension is initiated at around the bounce of the ball. If it was strictly a leverage aiding mechanism, it make would make way more sense from a timing perspective to just run around with their arms fully extended.

Would you provide a link to a video from a stroke archive
which supports your conjecture?
julian mielniczuk
usptapro 27873

[jperedo]

Would you provide a link to a video from a stroke archive
which supports your conjecture?
julian mielniczuk
usptapro 27873

Look at any of the videos from the players i listed (particularly short balls), where you can see the ball landing. The arm is far from straight until the ball bounces and the hips/torso rotates. Considering how fast the balls are kicking up at the pro level, they must have a good reason to make it this hard on themselves.

[johnyandell]

Carerra,

I appreciate that the tone of your arguments has dropped down and become somewhat more focused on the issues. Like I said all along if the straight arm forehand is the wave of the future I'll gladly go along. I've revised my views on many technical issues over the years. I'd rather evolve than be consistent. It's a waste of time to defend for the sake of defending.

I'm just not at all persuaded by what I've seen that this applies to every player at every level or should. It's funny that you have attacked the double bend concept so vociferously, because one of the things I've been talking about for a while with people like Brian Gordon was trying to figure out what the relative pluses and minuses are.

I think you undermine yourself by damning all other options as if you simply can't produce a great forehand except with your method. Also by trying to associate it with unnatural manipulations of the hand and arm, guiding the ball etc. Pete Sampras had one of the loosest forehand swings ever and blasted people off the court with his forehand. Since we can't clone him and repeat his career with a straight arm there is no way to determine if it could be even better.

I'm the who said coaches follow players and I believe it. It cannot be terrible that hundreds of elite players have intuitively found this structure. I didn't invent it! I discovered it in studying video--as well as seeing the straight arm.
So advocate for what you believe and be a pioneer and maybe you'll change things but please stop disparaging and dismissing everything else. Like I said it undermines you. We need to recapture civility in this forum, myself included, and I'll take whatever steps required.

[johnyandell]

Again, I'm in Cincinnati right now. I'm happy to meet your coach and you guys can submit an article if you can find the right voice and make a good presentation.

[carrerakent]

jperedo,

you are probably right.

[carrerakent]

don,

i've started replies to your post several times and can't seem to get finished before having to run off to something. you raise some good points that deserve discussion, etc.

i guess the place to start is in the long lever/fulcrum, whatever we want to call it. i don't think "long" is the answer, thus no i don't think longer rackets would be the answer. i think the whole meaning revolves around relaxed extension which results in the longest for the individuals anatomy.

there is a right brain - left brain thing that ties in to this that would take these discussion to another level, but in one other post i emphasize how much longer the extended forehand is over the double bend...up to 15 inches for me. if i am in my right brain and muscles are relaxed and set up to the ball properly (balanced, etc) and time the stroke properly, my relaxed extended racket will produce so much more racket head speed with such a minimal amount of force that i can focus my attention upon hitting my target and not trying (TRY being the optimum word as a left brain function) to hit the cover off of it like Gonzo and others.

So, if i can relax, swing much faster with less effort, hit my target more often because i understand proper alignment (because it is more required now), and i have basically one set up to every forehand with adjustment to height of contact point, then i will produce a shot that is more duplicatable and more of a nightmare for my opponents.

I agree with you that bent arm makes for easier adjustment...that is why it is so prevalent. Regardless of the level of play, players tend to move well, or not well in proportion to the challenge. I think that is why we see NTRP 3.0 players doing the same thing to adjust to the ball as Agassi did all the time...bend the arm.

To me, Federer's genius is in his body, kinesthetic awareness and ability to adapt with his hips, etc without conscious thought. John Yandell seems to question whether we should teach to that level of complexity. I contest that it is not complex, but the teaching methods of today and especially in the past do not allow for proper adjustments...IF the player is inclined. Because it is so easy to get away with tightening the muscles and slowing the racket head down to not make a mistake, then people take that approach. Human nature.

So if we can get players seeing better movement and better reading of the ball as the fix instead of just bending the arm and having as many arm configurations as there are ball reading screw ups, then all tennis players will be better than they are. They have to be...wouldn't you agree?

I don't care how good someone was or is...they could have been better with better movement and better set up to balls. the result of that is simply a result of better biomechanics around/thru the axis.

Most importantly maybe...is the contact zone! The common belief is as you say it that players have such a short period of time that the racket is actually in "alignment" with the ball and their target. I've been posting and trying to emphasize sweet spot behind the ball much much earlier in the take back and especially forward swing.

My coach's forehand, which is the only forehand I've ever seen that rivals federers in natural motion, extension and seemingly effortless power and spin, could make contact maybe 12-18 inches "late" behind the intended contact point and still the ball will go to the intended target because his sweet spot is in alignment with the ball almost from the instant it begins the forward motion. (i am working on that kind of position currently and notice that when the back of my back swing is behind the ball and not out and beside me, i hit so much harder and more accurately.)

That early position behind the ball becomes a very rigid straight arm forehand (that understandably has most people skeptical) when the proper elongation all the way from the shoulder out to the hands is not achieved. This elongation goes completely against what is required to hit a double bend forehand, therefore i am not surprised that everyone is having heart burn over this.

What you say about doing like Fed or Nadal is too challenging for us mortals is only true when accompanied by traditional biomechanics and left brain desire to hit hard and guide the ball with the arm and eyes.

I apologize is this is somewhat jumbled as I've been writing it in pieces.

Look forward to discussion.

[johnyandell]

Uh, so is the arm straight or not? And evolution is different than damnation. You are quite convinced but if you want to make impact you have to demonstrate this to the larger world in a way that convinces them.