Interactive Forum Februrary 2013: Petra Kvitova Forehand

[julian1]

Two schools here

Thanks, Julian.

I was referring to the whether elastic energy is a very significant factor in the SSC...or do elastic energy and SSC mean the same thing. Most Americans I speak to never seem to not know what I mean by "elastic energy", and I assume the term over there (for elastic energy) is actually SSC...or some other term we don't use over here. Elastic energy in sport is the storing of energy before unloading it. Getting this part precisely right will equal more power. Long jumpers and high jumpers for example have to get the storing of elastic energy spot on to maximise their jump. When I read BG's section on SSC it's sounds likes another term (or very similar) for elastic energy, no?

Do you use the term "elastic energy" over there?

Two schools here-
one says ssc is related to "elastic energy"
second says ssc is related to changes in entropy of muscles/tendons
Interestingly enough you have a similar problem analysing what tennis strings do.
From the point of view of tennis coaching it is NOT clear whether differences
between two schools above are IMPORTANT.
I kind of duck the issue and "jump" to ssc immediately.

Important related issues are:
1.define what is the meaning of word "optimize/maximize" (see your post as well
with a question).

2.define how long/large is a window to optimize

3.do we optimize only one part of movement or multiple parts?
(see the post by Don above)

4.can we learn from golf of baseball (see the post by tennis_chiro) above

5.Is it easier to teach ssc for forehand or double handed backhand?

6.How come Kvitova does NOT do a "flip" and she is ranked #6 on Tour?

Respectfully yours,
Julian

PS
Try to see whether you can get an access to tennisicoach.com to see a presentation by Bruce Elliot on Elastic Energy

A partial list of answers:
Kvitova generates forehand producing balls with speed around 80 miles per hour.
By the very definition she is hitting flat.
A flip would NOT help a lot with a speed of a ball.

[julian1]

Link I have sent you by e-mail

Why couldn't you have an SSC at the rotator cuff as well as the forearm? In fact, wouldn't the maximization be to have an SSC at the wrist flexors, the arm flexors, and then at the arm/shoulder joint (rotator cuff) and then even all the way to the pelvis (although I assume this would have to be to a much lesser degree). Just think of a major league pitcher coming down on his kick leg: isn't he creating a bit of an SSC at the pelvis and then down to the legs. If you are really using the power of the kinetic chain to its maximum, you are going to create a lot of SSC's. When you watch Rafa hit a forehand, you've got to believe he has more than one SSC being generated in that stroke.

don

It is NOT always possible two have both :
SSC of a rotator cuff AND a forearm.
Please see a blog I have referenced in my E-mail (in last two weeks)

[10splayer]

BTW:your post #20
I apologize getting into a your conversation with stroke
ssc you are talking about is ssc of muscles sourounding a rotator cuff
flip deals with different group of muscles,it least it is conjectured this way.

Yes, but how is the shoulder going to be rotated internally (before the pull) and the forearm rotated externall (supinated) and the wrist extended. In my opinion, it really is a case of all or nothing. Could be wrong....

[julian1]

It is complex

Yes, but how is the shoulder going to be rotated internally (before the pull) and the forearm rotated externall (supinated) and the wrist extended. In my opinion, it really is a case of all or nothing. Could be wrong....

I disagree that it is ALL or nothing.
I have to spend some time to think how to figure out how to convince you
I am NOT a quick thinker

[10splayer]

I disagree that it is ALL or nothing.
I have to spend some time to think how to figure out how to convince you
I am NOT a quick thinker

Ha ha, I'm sure you are a quick thinker...Figure it out and let me know.

[julian1]

Another answer to your question-Wikipedia

Thanks, Julian.

I was referring to the whether elastic energy is a very significant factor in the SSC...or do elastic energy and SSC mean the same thing. Most Americans I speak to never seem to not know what I mean by "elastic energy", and I assume the term over there (for elastic energy) is actually SSC...or some other term we don't use over here. Elastic energy in sport is the storing of energy before unloading it. Getting this part precisely right will equal more power. Long jumpers and high jumpers for example have to get the storing of elastic energy spot on to maximise their jump. When I read BG's section on SSC it's sounds likes another term (or very similar) for elastic energy, no?

Do you use the term "elastic energy" over there?

---->
Stretch shortening cycle
From Wikipedia, the free encyclopedia


A stretch-shortening cycle (SSC) can be defined as an active stretch (eccentric contraction) of a muscle followed by an immediate shortening (concentric contraction) of that same muscle.
Contents

1 Research studies
2 Community agreement
3 See also
4 References

Research studies

The increased performance benefit associated with muscle contractions that take place during SSCs has been the focus of much research in order to determine the true nature of this enhancement. At present, there is some debate as to where and how this performance enhancement takes place. It has been postulated that elastic structures in series with the contractile component can store energy like a spring after being forcibly stretched.[1] Since the length of the tendon increases due to the active stretch phase, if the series elastic component acts as a spring, it would therefore be storing more potential energy. This energy would be released as the tendon shortened. Thus, the recoil of the tendon during the shortening phase of the movement would result in a more efficient movement than one in which no energy had been stored.[2] This research is further supported by Roberts et al.[3]

However, other studies have found that removing portions of these series-elastic components (by way of tendon length reduction) had little effect on muscle performance.[4]

Studies on turkeys have, nevertheless, shown that during SSC, a performance enhancement associated with elastic energy storage still takes place but it is thought that the aponeurosis could be a major source of energy storage (Roleveld et al., 1994). The contractile component itself has also been associated with the ability to increase contractile performance through muscle potentiation (Cavagna, 1977) while other studies have found that this ability is quite limited and unable to account for such enhancements (Lensel and Goubel, 1987, Lensel-Corbeil and Goubel, 1990; Ettema and Huijing, 1989).
Community agreement

The results of these often contradictory studies have been associated with improved efficiencies for human or animal movements such as counter-movement jumps and running (Asmussen and Bonde-Peterson, 1974b; Cavagna, 1977; Komi, 1984b). However the jury is still out as to why and how this enhancement takes place. It is one of the underlying mechanisms of plyometric training.
See also

plyometrics

References

^ R. McNeill Alexander (2002). Principles of Animal Locomotion. Princeton University Press. ISBN 0-691-08678-8.
^ A. L. Hof and J. W. van den Berg (1986). "How much energy can be stored in human muscle elasticity?". Movement Science 5 (2): 107–114. doi:10.1016/0167-9457(86)90018-7.
^ Thomas J. Roberts, Richard L. Marsh, Peter G. Weyand and C. Richard Taylor (1997). "Muscular Force in Running Turkeys: The Economy of Minimizing Work". Science 275 (5303): 1113–1115. doi:10.1126/science.275.5303.1113. PMID 9027309.
^ R. Baratta and M. Solomonow (1991). "The effect of tendon viscoelastic stiffness on the dynamic performance of isometric muscle". Journal of Biomechanics 24 (2): 109–116. doi:10.1016/0021-9290(91)90355-Q. PMID 2037610.

[tennis_chiro]

Tennisspeed blog

It is NOT always possible two have both :
SSC of a rotator cuff AND a forearm.
Please see a blog I have referenced in my E-mail (in last two weeks)

So, is Tennisspeed (http://blog.tennisspeed.com/) BG's blog? Sure seems like it must be. In any case, it is even tougher to digest than Brian's articles here on Tennisplayer with JY's editing skills. I just haven't found the time to slog through the whole thing although I would like to.

And this is turning out to be an interesting little thread. BTW, I wrote in 10sBalls.com after she won the WTA Finals in Istanbul that I thought Kvitova was going to rule the roost for a few years. It seems people are trying to point out that she hits the ball pretty big inspite of a rather minor "flip". But to me, when she is on, the only player that has any chance of staying with her is Serena. It seems to me she hits bigger than any of the other women and the big lefty serve is a huge weapon. Her struggles are a puzzle to me, but I don't think it is the mechanics of her strokes; more likely fitness and mental focus and commitment. She seems to me almost afraid of the trappings of being on top of the mountain.

don

[johnyandell]

NO! Tennisspeed isn't BG. In fact BG might tell you a thing or two about that guy and how he appropriated some conclusions... and twisted them to his own claims...and yeah it's hard to understand...

[stotty]

---->
Stretch shortening cycle
From Wikipedia, the free encyclopedia


A stretch-shortening cycle (SSC) can be defined as an active stretch (eccentric contraction) of a muscle followed by an immediate shortening (concentric contraction) of that same muscle.
Contents

1 Research studies
2 Community agreement
3 See also
4 References

Research studies

The increased performance benefit associated with muscle contractions that take place during SSCs has been the focus of much research in order to determine the true nature of this enhancement. At present, there is some debate as to where and how this performance enhancement takes place. It has been postulated that elastic structures in series with the contractile component can store energy like a spring after being forcibly stretched.[1] Since the length of the tendon increases due to the active stretch phase, if the series elastic component acts as a spring, it would therefore be storing more potential energy. This energy would be released as the tendon shortened. Thus, the recoil of the tendon during the shortening phase of the movement would result in a more efficient movement than one in which no energy had been stored.[2] This research is further supported by Roberts et al.[3]

However, other studies have found that removing portions of these series-elastic components (by way of tendon length reduction) had little effect on muscle performance.[4]

Studies on turkeys have, nevertheless, shown that during SSC, a performance enhancement associated with elastic energy storage still takes place but it is thought that the aponeurosis could be a major source of energy storage (Roleveld et al., 1994). The contractile component itself has also been associated with the ability to increase contractile performance through muscle potentiation (Cavagna, 1977) while other studies have found that this ability is quite limited and unable to account for such enhancements (Lensel and Goubel, 1987, Lensel-Corbeil and Goubel, 1990; Ettema and Huijing, 1989).
Community agreement

The results of these often contradictory studies have been associated with improved efficiencies for human or animal movements such as counter-movement jumps and running (Asmussen and Bonde-Peterson, 1974b; Cavagna, 1977; Komi, 1984b). However the jury is still out as to why and how this enhancement takes place. It is one of the underlying mechanisms of plyometric training.

For tennis purposes, the studies are not so entirely different as it doesn't matter whether it's the tendons or the aponeurosis storing the energy...it's enough for us to know it is stored somehow.

The question is whether it can be optimised. All forehands are good in the men's game...yet despite having similar shapes (in many cases paths are similar) some are better than others...no question. It could be that optmising SSC (or elastic energy) might be the separating factor between forehands that are very good and those that are great. Federer's split second timing of flip could simply be better than other players and that is why the shot is so good...and also so versatile. What makes Federer's forehand the best ever (the best single shot of all time come to that) is it's versatility.

[10splayer]

For tennis purposes, the studies are not so entirely different as it doesn't matter whether it's the tendons or the aponeurosis storing the energy...it's enough for us to know it is stored somehow.

The question is whether it can be optimised. All forehands are good in the men's game...yet despite having similar shapes (in many cases paths are similar) some are better than others...no question. It could be that optmising SSC (or elastic energy) might be the separating factor between forehands that are very good and those that are great. Federer's split second timing of flip could simply be better than other players and that is why the shot is so good...and also so versatile. What makes Federer's forehand the best ever (the best single shot of all time come to that) is it's versatility.

Agreed. Some things are unexplainable. How does one explain Nolan Ryan, who threw 95 miles an hour into his late 40's, even while using a conventional delivery...Some people are just more gifted.

[julian1]

Kvitova

So, is Tennisspeed (http://blog.tennisspeed.com/) BG's blog? Sure seems like it must be. In any case, it is even tougher to digest than Brian's articles here on Tennisplayer with JY's editing skills. I just haven't found the time to slog through the whole thing although I would like to.

And this is turning out to be an interesting little thread. BTW, I wrote in 10sBalls.com after she won the WTA Finals in Istanbul that I thought Kvitova was going to rule the roost for a few years. It seems people are trying to point out that she hits the ball pretty big inspite of a rather minor "flip". But to me, when she is on, the only player that has any chance of staying with her is Serena. It seems to me she hits bigger than any of the other women and the big lefty serve is a huge weapon. Her struggles are a puzzle to me, but I don't think it is the mechanics of her strokes; more likely fitness and mental focus and commitment. She seems to me almost afraid of the trappings of being on top of the mountain.

don

Let me state one obvious fact.
Kvitova generates a fast SPINLESS LOW BOUNCING ball.
It is interesting that the LACK of SPIN keeps a ball away from a comfort zone
of an opponent.
It is completely different philosophy than ,say, of Federer
Regards,
Julian

[julian1]

Kvitova vs Sharapova

I have tried to compare with Sharapova

http://www.tennisplayer.net/members/strokearchive/high_speed/High_Speed.html?MariaSharapovaForehand.mov

1,The video above has a HIGHER ball

[julian1]

Straighter arm better?

For tennis purposes, the studies are not so entirely different as it doesn't matter whether it's the tendons or the aponeurosis storing the energy...it's enough for us to know it is stored somehow.

The question is whether it can be optimised. All forehands are good in the men's game...yet despite having similar shapes (in many cases paths are similar) some are better than others...no question. It could be that optmising SSC (or elastic energy) might be the separating factor between forehands that are very good and those that are great. Federer's split second timing of flip could simply be better than other players and that is why the shot is so good...and also so versatile. What makes Federer's forehand the best ever (the best single shot of all time come to that) is it's versatility.

Licensedcoach,

couple very simple remarks.
I decided to talk a bit about your phrase "optimized".

There is a conjecture:
if a hitting arm straighter an SSC is more pronounced/"optimized"
(a purist can say that it is trivial and comes from the definition of SSC).
The same conjecture holds,more or less,for BOTH arms of double handed backhand
and SERVE.
Generally if an SSC is "MORE PRONOUNCED" a racket head speed is HIGHER
or a ball PRODUCED is HEAVIER (or ,say,both)

See as well
http://tt.tennis-warehouse.com/showthread.php?t=455783 post #12
by John Yandell discussing related subjects.

A different terminology uses the phrase "elbow extended" or "elbow extension"
to describe SOME forehands.
A definition of ELBOW EXTENSION can be provided by pictures.
One can have PARTIAL CASES when a hand from an elbow down is straight-see
the video of Kvitova in post #1

A FULL EXTENSION can be defined via a video of NADAL

http://www.tennisplayer.net/members/high_speed_archive/phantom/Rafael_Nadal_HD_HS/index.html?dir=Forehand/RN_FH_Center&stroke=RN%20FH%20Center%20OpenStance%20Front1%20500fps.mp4

or in the case of Federer

http://www.tennisplayer.net/members/high_speed_archive/phantom/Roger_Federer_HD_HS/index.html?dir=Forehand/RF_FH_Center&stroke=RFFHCenterOpenStanceSide1_500fps.mp4

Regards,
Julian
One can have similar scenarios when spiking in volleyball.
There is a notion of a whip in volleyball.
See as well videos in

http://www.golfloopy.com/role-of-right-arm-in-golf-downswing/

[julian1]

Exercises

For tennis purposes, the studies are not so entirely different as it doesn't matter whether it's the tendons or the aponeurosis storing the energy...it's enough for us to know it is stored somehow.

The question is whether it can be optimised. All forehands are good in the men's game...yet despite having similar shapes (in many cases paths are similar) some are better than others...no question. It could be that optmising SSC (or elastic energy) might be the separating factor between forehands that are very good and those that are great. Federer's split second timing of flip could simply be better than other players and that is why the shot is so good...and also so versatile. What makes Federer's forehand the best ever (the best single shot of all time come to that) is it's versatility.

Basically you "OPTIMIZE" by performing SSC exercises.
At some moment you/one gets better but it maybe long and painful.

[julian1]

Pitching/baseball

Agreed. Some things are unexplainable. How does one explain Nolan Ryan, who threw 95 miles an hour into his late 40's, even while using a conventional delivery...Some people are just more gifted.

Do u have a good reference for ssc for golf OR/AND baseball?
See videos in

http://www.golfloopy.com/role-of-right-arm-in-golf-downswing/