Nadal's 130 plus MPH serve

[blake_b]

Hi Don,

Can you explain how a stronger continental grip would increase internal shoulder rotation? I could see how it might increase forearm pronation slightly, but Brian Gordon has the following to say about that

"The reality is that independent forearm pronation is used more for positioning the wrist joint and racquet head than for generating racquet head speed. "

I think we also have to consider if an increase in pronation would be a stronger factor than the racquet angle at contact.

Blake

[uspta990770809]

Why me? Why not?

Hi Don,

Can you explain how a stronger continental grip would increase internal shoulder rotation? I could see how it might increase forearm pronation slightly, but Brian Gordon has the following to say about that

"The reality is that independent forearm pronation is used more for positioning the wrist joint and racquet head than for generating racquet head speed. "

I think we also have to consider if an increase in pronation would be a stronger factor than the racquet angle at contact.

Blake

Okay, this is as good a way to fight insomnia as I know of. And I'd like to kind of get some more discussion out there on this idea. I know from experience both hitting it and teaching top players to serve huge that "pronation" works. And that the stronger continental grip is important for it to be able to work fully. But the recent work that John and Brian have done with the high speed filming of Sampras's service motion call a lot of assumptions into question. I think the following quote from the previous article on Sampras's Racket Head Speed sheds a little light on what we are talking about:

Pronation is a tricky term because in coaching lexicon it has become associated with the counter clockwise turning of the racket face after contact. Technically though, in biomechanical terms, it refers only to the rotation of the forearm between the elbow and the wrist. The reality is that as the racket goes up toward contact, it is actually rotating from the shoulder as well

We (teaching pros) tend to talk about pronation in the "coaching lexicon" terms rather than what would be more technically correct, the "biomechanical terms" (which do not include internal rotation of the shoulder). The pictures show that true "biomechanical" pronation is very limited prior to actual contact and can not, therefore, be that great a contributor to actual speed. But wait a minute. Maybe true pronation may not be an actual major motor unit, but it may be a critical enabler. There is considerably more true pronation, according to these pics, after contact.

When I'm trying to teach someone to get more pronation and use an advanced (strong continental) grip, I have the student do the following. Granted, I developed the drill when I had a weaker and actually incorrect understanding of the nature of the angle between the outstretched arm and the racket shaft at contact. I used to think the racket reached straight up to the ball, but we know that is not the case. Despite that false beginning, the drill does have merit. I have the student reach up to the contact point, stop, and then reverse the motion of the racket head, down from the ball, first rotating the face 90 degrees and then cocking the wrist back and then bending the elbow (obviously, I'm going to start emphasizing the reversal of the internal rotation of the upper arm a whole lot more). We're moving towards the lowpoint (where the racket was at just 30 MPH for Pete). This is an isolation exercise so we won't have that speed here. Now we go back up to contact and continue through contact, but stopping the outstretched arm until the racket head has continued to where the head of the racket is now pointing down. As I think this through, we don't even go all the way back down to the low point with the elbow bending; we do this whole exercise with almost no movement of the elbow. Now I can do this move pretty well and actually make the racket head whistle because I understand how to use "pronation" (the coaching lexicon kind). It's fun for me because the young studs that can beat the *!#* out of me and serve probably 30mph faster than I can (I'm 62 next week) struggle to move the racket with any kind of speed at all. Oh, they are using the motion (somewhat) when they serve, but they don't know how to isolate it. Furthermore, if you try to do what I am talking about (remember this is a drill and not meant to be a duplication of what the true motion is doing because we would have all those side angles and shoulder moves, etc.) with that strong Eastern forehand grip, you can't because you damn near break your wrist (literally) as you go over the top. The easiest way (for a beginner) to hit a serve is to pick up the racket like a frying pan (semi-Western) and tap the ball with no rotation of the racket head as it approaches the ball; and that is what most beginners do, at least on their second serves. That grip directs the ball nicely, but it does not allow the wrist to pronate or the upper arm to internally rotate to the contact. If you did, the ball would go way off to the right. Try this and you will see what I am talking about. But when you use the Continental grip, you have to use pronation (really mostly shoulder/upper arm internal rotation) to bring the racket face into an orientation that can direct the ball to the target. Furthermore, when you build up real speed, you need to be able to release just as quickly as you built up (by the article we go up 60 mph in .1 sec and then down 60 mph in .1 sec). If you don't have the continental grip, you can't pronate in the follow through sufficiently to release all that energy without hurting yourself (so your body just doesn't swing that fast.) That's one way to look at it. Another is that all that energy has been built up by the kinetic chain and it's got to go somewhere. Sure a lot goes to the ball, but there is a lot left. The continental grip allows a greater range of motion for the racket head immediately after the contact point to dissipate that energy. For all that speed and that signature follow through on his serve, I don't remember Pete having a lot of arm trouble. And he still has a pretty live arm today as demonstrated in his exhibition series with Federer in 2009!

I hope that spurs some further discussion. I hope John and Brian have a comment. I know this is not backed up by any scientific study, but I think I am on the right track here.

So I am saying I think that positioning of the racket head (with pronation) actually enables greater racket head speed. I really thought it did even more, but the pictures tell a different story. I still think Rafa will serve in the 140's at next year's Open when he learns to truly utilize everything he can get out of "pronation". And he will learn.

don

[uspta146749877]

do you think Don answered your question?

Hi Don,

Can you explain how a stronger continental grip would increase internal shoulder rotation? I could see how it might increase forearm pronation slightly, but Brian Gordon has the following to say about that

"The reality is that independent forearm pronation is used more for positioning the wrist joint and racquet head than for generating racquet head speed. "

I think we also have to consider if an increase in pronation would be a stronger factor than the racquet angle at contact.

Blake

Your quote
---->
Can you explain how a stronger continental grip would increase internal shoulder rotation?
--->
so do you think Don answered your question?

[BrianGordon]

I was asked to add my input – so here it goes:

I believe Don pretty much has it right if I read him correctly (don’t know about the dissipation of energy thing because I neither track energy flow nor focus on post impact mechanics in my work).

I’ve discussed over time a pretty specific chain of hitting arm joint rotations measured in good servers. These are shoulder abduction, shoulder external rotation, and wrist extension (early upward swing); elbow extension and ulnar deviation (middle portion); and shoulder internal rotation, pronation, and wrist flexion (near contact).

Recent work showed that pronation/supination (twist rotation of the forearm independent of twist rotation of the upper arm – anatomical lexicon) was actually neutral to supination based on a method I devised to more accurately measure this. In other words the forearm rotation is driven by the upper arm rotation (from shoulder internal rotation) and slight independent pronation or supination is used as a fine-tuning adjustment to insure the wrist flexion axis is appropriately aligned.

Sequentially stepping through these motions in slow-mo (as in the theory behind Don’s drill) with different grips should illuminate that a continental grip optimizes the ability to derive appropriate range of motion from ALL of the mentioned sources while STILL MAINTAINING AN APPROPRIATE RACQUET ORIENTATION AT CONTACT.

With some functionally viable tweaks they can also ALL be utilized with up to an eastern backhand grip. But… unless one is gumby-ish, there are problems with a forehand grip. In particular, shoulder internal rotation and wrist flexion become increasingly compromised as viable sources of racquet head speed. As these two sources are typically linked to about 70 - 80% of racquet speed near contact, replacing them (which is what would be required with a forehand grip) seems problematic at best.

As for Nadal, in my observation during the open after this forehand thing came out, following his numerous micro-adjustments prior to settling in to the final grip, I could never see an instance where he appeared to be in anything less (relative to the forehand grip) than a pure continental and usually slightly to the backhand of continental – less to the backhand than in the past – but certainly not to the forehand.

OR maybe he is gumby. But as one of the more extreme shoulder internal rotators I’ve seen – I doubt it. I tend to agree with the school that proposes that he has always had the capability to go 130+ (not a huge accomplishment for tour players these days) but only recently realized the confidence, or felt the need, to use the howitzer on stage – like on fast hard courts at a tournament that had significantly eluded him – as usual, I could be wrong.

[gzhpcu]

My questions here: doesn't the continental, or even more so, the eastern backhand, grip result in more leverage, because the angle between the forearm and the racket shaft increases as pronation occurs? You end up hitting the ball a bit lower than with a forehand grip, but there is more racket movement and leverage.

Isn't the elbow pointing upwards after impact a sign of strong shoulder internal rotation?

[johnyandell]

God this is good stuff.

[gzhpcu]

My questions here: doesn't the continental, or even more so, the eastern backhand, grip result in more leverage, because the angle between the forearm and the racket shaft increases as pronation occurs? You end up hitting the ball a bit lower than with a forehand grip, but there is more racket movement and leverage.

Actually, I was not clear here: doesn't the continental, or even more so, the eastern backhand grip result in more leverage as pronation occurs due to the resulting greater angle (compared to the forehand grip) between the forearm and the racket shaft.

[BrianGordon]

Phil-

Use of one grip or the other does not guarantee (or preclude) the angle of which you speak - look at the back view of many players in the archive (especially the gals) and you will see plenty of examples of continental grips and no angle (by the way, don't think leverage is what you mean unless it is another coaching lexicon - rather radius of rotation [vector r in v=angular velocity x r]).

Instead the continental-to-eastern backhand enables shoulder internal rotation to be linked beneficially to FORWARD racquet velocity if the a player CHOOSES to build that angle in - not an option with a forehand grip for obvious reasons (bye bye 40% to FORWARD speed from internal rotation).

Semantics aside, the spirit of your question indicates to me you are on the right track as I see it. Again, the continental allows beneficial use of ALL the joint motions I mentioned, but does not mandate it - if it did I would not have much to do. The forehand grip explicitly complicates using certain rotations to contribute to forward velocity near contact - an overall drain on speed potential through elimination of degrees of freedom, unless compensatory rotations can be used - good luck.

[johnyandell]

Continental meaning here knuckle on bevel two, heel pad mostly or at least partially on bevel one???

[gzhpcu]

Thanks Brian...

[BrianGordon]

Continental meaning here knuckle on bevel two, heel pad mostly or at least partially on bevel one???

Now that's embarrassing - thought the heel pad was in my shoe - don't tell anyone at La Quinta - but... after running up to the academy to get my racquet I'd say your description is pretty much what I mean.

[blake_b]

Brian basically answered my question about how grip can impact internal shoulder rotation when comparing a continental to a forehand grip. However, most sources that I read or heard indicate that Nadal moved his grip from an eastern backhand TOWARDS an eastern forehand. They did not state that he moved TO an eastern forehand grip. I think this is a significant distinction. Brian states much the same thing when he says "less to the backhand than in the past".

One thing that I did not see addressed in Brian's post was how the grip affects the angle of impact with the ball. Given the same toss location it seems that an eastern backhand will have a slightly different angle of impact than a continental which can produce more spin and less speed. If you look at some of Nadal's older first serves in the stroke archive you will see that his toss is pretty far to his right compared to other left handed players. His racquet face is also not as parallel to the net (at impact) as many top players.

Based on the picture that Phil posted, it seems that he moved his toss to the left and adjusted his grip away from the eastern backhand.

If John gets a chance to film Nadal in the future, it would be an interesting analysis to see exactly how his serve has changed.

[llll]

I tend to agree with the school that proposes that he has always had the capability to go 130+ (not a huge accomplishment for tour players these days) but only recently realized the confidence, or felt the need, to use the howitzer on stage – like on fast hard courts at a tournament that had significantly eluded him – as usual, I could be wrong.

in this us open interview (towards the last 1/3 of the interview) rafa says "i changed the grip alittle but mainly i changed the decision"(paraphrasing) he goes on to say he still needs to continue to work to imorove it because he doesnt own it yet. (again paraphrasing)

http://www.usopen.org/en_US/interactive/video/index.html?promo=PhotoInNav&category=press

[llll]

Yeah, I missed the logo on the youtube video. So the speaker must be Christoffe. He's done a nice job here.

its christophe not christoffe and definitely not chris or chritopher.
i should know i take lessons with him

[uspta146749877]

Angle of impact

Brian basically answered my question about how grip can impact internal shoulder rotation when comparing a continental to a forehand grip. However, most sources that I read or heard indicate that Nadal moved his grip from an eastern backhand TOWARDS an eastern forehand. They did not state that he moved TO an eastern forehand grip. I think this is a significant distinction. Brian states much the same thing when he says "less to the backhand than in the past".

One thing that I did not see addressed in Brian's post was how the grip affects the angle of impact with the ball. Given the same toss location it seems that an eastern backhand will have a slightly different angle of impact than a continental which can produce more spin and less speed. If you look at some of Nadal's older first serves in the stroke archive you will see that his toss is pretty far to his right compared to other left handed players. His racquet face is also not as parallel to the net (at impact) as many top players.

Based on the picture that Phil posted, it seems that he moved his toss to the left and adjusted his grip away from the eastern backhand.

If John gets a chance to film Nadal in the future, it would be an interesting analysis to see exactly how his serve has changed.

Two points/open questions:
1.how a speed of a racket translates to a speed of a ball ?
2.what is a dependence of a force produced by a racket on an angle of impact?
Some partial answers are known.
I will try to write something on this subject tomorrow.