Serve speed based more on strength or technique?

So I've played with the RF97 for the past 2-3 years. My ground strokes with it are fine but my serve has always been a bit lacking. Then I recently tried out a lighter racket, the Clash 98 and I suddenly felt like my serves were a lot better since I felt like I could swing the racket faster. I feel like decrease in weight was the reason that my serve was faster. Which made me wonder, do I just need to get stronger so that I can serve with the RF97 better, (I do question how much difference a 31 gram diff makes tho in terms of required strength) or if it was mostly just my technique that's lacking which prevents me from swinging it on serve as freely.
 

Chas Tennis

G.O.A.T.
Try high speed video to compare your technique and those being used by the best servers. The only technique that works for comparing will probably be the technique that you see used by 99% of the top 100 ATP players. That technique involves internal shoulder rotation for significant racket head speed.

If you have another serving technique, nobody knows.

Currently, serve speed probably depends on technique and height of impact (the service box presents a larger target for high impact heights). But "strength" is complicated.

Strength is usually measured by the greatest weight that can be lifted in a slow movement, such as a bench press. This force of 'strength' depends on the Actin and Myosin of the sarcomere. The muscles shorten because the many microscopic sarcomeres, end-to-end, shorten. These forces are called 'Active' forces. Google: sarcomere actin myosin animation

One definition of 'strength' is maximum weight lifted.

But the highest muscle shortening speed - think force vs speed - depends more on the stretch shorten cycle and the Titin 'rubber band'-like molecules in the sarcomeres. Force vs shortening speed is more important than 'strength' by any common definition. 'Strength' is typically defined for very slow muscle shortening speeds, as for weight lifters.

(No, the tendons probably don't stretch to supply the main forces in the muscles. Recent reference books will still attribute the stretch shorten cycle to 'elastic' tendons. The new reference books describing Titin may not have appeared yet.)

Google: Titin Herzog
 
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fuzz nation

G.O.A.T.
So I've played with the RF97 for the past 2-3 years. My ground strokes with it are fine but my serve has always been a bit lacking. Then I recently tried out a lighter racket, the Clash 98 and I suddenly felt like my serves were a lot better since I felt like I could swing the racket faster. I feel like decrease in weight was the reason that my serve was faster. Which made me wonder, do I just need to get stronger so that I can serve with the RF97 better, (I do question how much difference a 31 gram diff makes tho in terms of required strength) or if it was mostly just my technique that's lacking which prevents me from swinging it on serve as freely.

To answer the question in your title, I have to say that it's a lot of both. Strength is very helpful, especially in terms of keeping us sound (uninjured) when we're hitting serves over and over again. But that doesn't mean that more strength is automatically better. Without decent technique and a proper kinetic chain at work, a lot of that strength can be wasted. Bad technique will also put a lot of stress on perhaps a player's back, shoulder, wrist, etc.

I'm not a gym rat - I workout to keep me healthy and functional on the courts. That being said, I can easily serve much faster with my 12.5 oz. Volkl C10's than I can with lighter alternatives like the 2015 Wilson Blades that I tried for a while last year. I think that's about technique - the C10's are a better fit for my technique even though the Blades are lighter and perhaps easier to swing.

I occasionally play with a couple of guys who are really strong dudes - they both probably weigh in at around 230 lbs. or more. Yes they can crush their serves. One of them hits a heater that's a legit 110 mph bomb. Can they sustain that for two hours? No. They don't have the technique to power those serves from the ground up. After serving several games, they start to wear down in their arms & shoulders.

Strength is helpful, technique is also helpful, but I think that you're also finding that some racquet layouts (weight, balance, etc.) will fit with your individual technique better than others. Getting stronger will probably help you serve bigger, but your technique will hopefully evolve, too. Getting stronger should also boost your endurance, protect your rotator cuffs, etc.
 

TheIntrovert

Hall of Fame
It’s about both, but technique comes first. Strength alone with bad technique will only get you so far. Good technique has a much higher threshold. And good technique will also train and strengthen the muscles you need the most on your serve, like shoulder and back.
 
I would say technique is 70% of serve speed if you have the basic "explosive" strength to use the rf.
Explosive arm and shoulder strength is key, not slow methodical overhead press or what you might use on a bench press to steadily bring the bar higher.

Life long players should have that base strength.

I would switch sticks if I was you, unless your serve isn't a weapon no matter what racket you use.

Your height could also be a factor.
 

FiReFTW

Legend
Both.

Technique maybe 70% but physical 30%

And by physical I don't mean pure strenght, strenght is something else, its more explosiveness and power, ability to create alot of power as fast as possible with the muscles involved in the serve, legs, core, back etc..
 

Mountain Ghost

Professional
If you're wondering where to put your ATTENTION ... probably 100% on technique! A strong person with bad technique will NEVER get as "far" ... or as "fast" ... as an average-strength person with excellent technique. I have actually found very "strong" students to be "tight" ... with much less flexibility, "reach" and leverage than those with less "ego-muscle" ... ... ... and the same goes for equipment ... ... ... it's not the "airplane" ... it's the "PILOT" !!! ~ MG
 
I just though of this too, my serve improved about 15% when I was doing yoga 3 times a week. I know it's a commitment, but I think it will directly translate into better serves for anyone along with other benefits.
 
I would say 70% technique and 30% strength.

There are 13 year old juniors who can serve 90 mph when they are 5'5 120. An elite power lifter with no technique wouldn't even come close to that.

Of course to serve 120+ you also need quite a bit of strength but I would say anyone with good technique who is strong enough to do 15 push ups could serve 90+ in theory. Note though to to attain perfect technique you also need physical skill like shoulder flexibility. If your shoulder and scapula isn't flexible enough you won't attain perfect technique.
 

coupergear

Professional
Coco served 120 MPH when she was 14 at Wimbledon.
This. To me that means it's more like 90% to 10. Her relative strength to just about anybody else besides little kids is going to be very weak. Yet she can crank it up to 120 that tells me strength has very little to do with it. Kinetic chain, as they like to say on here.
 

AlexR

Rookie
I’ll say 50% technique, 25% strength, 25% flexibility. You cannot serve 130 mph without strength AND flexibility. The world’s strongest man still needs runway to accelerate the racquet. Everything you’re told to do with the racquet prior to swinging it up to the ball is about giving the racquet the longest possible runway. The longer the runway before ball strike, the longer you’re putting force into the racquet to accelerate it. Roddick and Sampras and all the great servers have freakish shoulder flexibility. I think it’s possible to hit 100 mph for almost anyone with good technique and decent strength. 120 might be the limit for a really strong guy with average flexibility. I don’t think anyone cracks 130 without being a freak in strength AND flexibility.
 

BetaServe

Professional
Proof that strength plays a big part:

Check the sky hook smash by fed at 1:22 and 1:48 (watch the replay as well)

Fed can snap the sh*t out of that ball from that position because his wrist/forearm are strong af. Amateurs like us can never hit that kind of smash winner with that much pace simply because our wrists/forearms aren't strong enough.
 

mad dog1

G.O.A.T.
So I've played with the RF97 for the past 2-3 years. My ground strokes with it are fine but my serve has always been a bit lacking. Then I recently tried out a lighter racket, the Clash 98 and I suddenly felt like my serves were a lot better since I felt like I could swing the racket faster. I feel like decrease in weight was the reason that my serve was faster. Which made me wonder, do I just need to get stronger so that I can serve with the RF97 better, (I do question how much difference a 31 gram diff makes tho in terms of required strength) or if it was mostly just my technique that's lacking which prevents me from swinging it on serve as freely.
Both are important. the order of importance? Technique first. Strength next.

What level are you? If you play at a level lower than 5.0, you get the most gains working on technique but even then it doesn’t mean your serve wouldn’t benefit from a lighter racquet than the RFA97.

If you are brave enough, post a video of your serve here and we can tell you if it’s your technique or strength that needs more attention.
 
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This. To me that means it's more like 90% to 10. Her relative strength to just about anybody else besides little kids is going to be very weak. Yet she can crank it up to 120 that tells me strength has very little to do with it. Kinetic chain, as they like to say on here.

Coco is tremendously strong for her age, I'm pretty sure she lifts at least 4 times a week.

 

Chas Tennis

G.O.A.T.
.........................Everything you’re told to do with the racquet prior to swinging it up to the ball is about giving the racquet the longest possible runway. The longer the runway before ball strike, the longer you’re putting force into the racquet to accelerate it. ............................

Many of the sub-motions of the service motion specifically have to do with the stretch shorten cycles for certain shoulder muscles. When internal shoulder rotation (ISR) was finally realized by tennis researcher in the 1990s, some complete misconceptions were set straight. Some of the main sub-motions for ISR and other reasons were identified and called:
1) leg thrust (jump)
2) Shoulder-over-shoulder (cartwheel)
3) Trunk twist.
4) and other sub-motions

All these sub-motions occur with a bent elbow and racket properly positioned, and move the shoulder mass to, in turn, cause inertia and that inertia, in turn, causes external shoulder rotation (ESR). ESR lengthens and stretches muscles that later perform Internal shoulder rotation (ISR). ISR is the rotation of the humerus around the long axis that runs along the centerline of the humerus. The humerus does not go anywhere, it rotates around its centerline. There are many other joint motions contributing to the service motion. But the largest single joint motion participating in racket head speed at impact is internal shoulder rotation. How was that missed for decades!

Your "runway" view is missing the above biomechanics that are very interesting and significant for the high level serve. The above biomechanics are not known by most tennis players.

Google and forum search: internal shoulder rotation Chas
 
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Dragy

Legend
Proof that strength plays a big part:

Check the sky hook smash by fed at 1:22 and 1:48 (watch the replay as well)

Fed can snap the sh*t out of that ball from that position because his wrist/forearm are strong af. Amateurs like us can never hit that kind of smash winner with that much pace simply because our wrists/forearms aren't strong enough.
Those shots, skyhook or BH smash, are technical. No forearm power will give you enough. You need to swing all arm up to build up racquet speed and then slow down/stop the arm so that racquet pivots rapidly at proper time and with intended trajectory.
 

Chas Tennis

G.O.A.T.
Proof that strength plays a big part:

Check the sky hook smash by fed at 1:22 and 1:48 (watch the replay as well)

Fed can snap the sh*t out of that ball from that position because his wrist/forearm are strong af. Amateurs like us can never hit that kind of smash winner with that much pace simply because our wrists/forearms aren't strong enough.

The slow motion at 1:41 looks as if he might have used ISR plus near straight arm shoulder abduction and wrist motions. ISR is always cable of power because the lat is the largest muscle attached to the arm. (To single frame on Youtube use the "," and "." keys.)

ISR can produce rapid racket head motion because the straight arm has a small moment of inertia and the racket, at an angle to the forearm, is light weight so its moment of inertia is not large. The large lat muscle can rotationally accelerate the near straight arm and light weight racket to high speed. Plus there are other motions. In that video the use of ISR and wrist motion resembles their use for a serve.
 
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SystemicAnomaly

Bionic Poster
I believe that many here are confusing muscle power (explosiveness) with muscle strength. Power is a function of Type IIa and Type Type IIx fast-twitch muscles. These can be developed with medicine ball work and other plyometric exercises.

Olympic (power)lifting rather than traditional strenghth development or bodybuilding focuses on both types of fast-twitch muscle fibers. Strength is more about muscle mass. It focuses more on Type IIa and Type I (slow-twitch) fibers.

https://blog.bridgeathletic.com/muscle-fiber-types-and-their-adaptations-through-training
 
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SystemicAnomaly

Bionic Poster
Both technique and optimal timing are much more important than muscle strength. An optimal use of the kinetic chain will generate greater RHS and ball speed. Flexibilty is also a factor. Muscle power is also more important than muscle strength. (Not to say that some strength is not important at all).

Coco is tremendously strong for her age, I'm pretty sure she lifts at least 4 times a week...

She has developed power in addition to some strength development. She has sprinter's legs. This is more of a sign of power (explosive/speed strength) rather than conventional strength.

Proof that strength plays a big part:

Check the sky hook smash by fed at 1:22 and 1:48 (watch the replay as well)

Fed can snap the sh*t out of that ball from that position because his wrist/forearm are strong af. Amateurs like us can never hit that kind of smash winner with that much pace simply because our wrists/forearms aren't strong enough.

Nope, not really a sign of strength. More, a sign of timing, technique and muscle power (not to be confused with strength).

Compare Rafa to Roger. Rafa has more muscle mass and appears to be stronger than Roger. Yet Roger's average serve speed and fastest serves (> 140 mph) are greater than Rafa. Rafa's fastest serve mph has been in the 130s.

Stan W also appears to have more muscle mass and strength than Roger. Yet their fastest serve speeds are nearly the same. Roger has better, more efficient, technique on the serve than Stan. Roger makes better use of the kinetic chain.
 
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Kevo

Legend
Well, it's hard to say whether or not you could just get stronger in the way you need. There's also a big difference in frames as to where the mass is located. If you're technique is sound and your serve is a weak spot in your game even with the good technique, then I would say go with a lighter frame. Test a few out and make sure they don't degrade your ground game too much. Also try to get stronger as well, but getting stronger doesn't always mean faster. You have to train for what you want to improve, so sports specific exercises would likely be the best bet.
 

SystemicAnomaly

Bionic Poster
Well, it's hard to say whether or not you could just get stronger in the way you need...

Also try to get stronger as well, but getting stronger doesn't always mean faster. You have to train for what you want to improve, so sports specific exercises would likely be the best bet.

Only moderate strength is needed for tennis. Some strength development ok but power training with plyomeyric excercises should be stressed much more than standard strength training.

http://www.playerdevelopment.usta.c...Conditioning_Plyometric_Exercises_for_Tennis/

http://www.mattspoint.com/blog/ultimate-guide-plyometrics-tennis
 

sredna42

Hall of Fame
Coco served 120 MPH when she was 14 at Wimbledon.
I know that the pros are on a different league than rec hacks, and are an order of magnitude better at everything, but even still I am a bit dubious about the serve speeds on tv sometimes.
 

dgold44

G.O.A.T.
So I've played with the RF97 for the past 2-3 years. My ground strokes with it are fine but my serve has always been a bit lacking. Then I recently tried out a lighter racket, the Clash 98 and I suddenly felt like my serves were a lot better since I felt like I could swing the racket faster. I feel like decrease in weight was the reason that my serve was faster. Which made me wonder, do I just need to get stronger so that I can serve with the RF97 better, (I do question how much difference a 31 gram diff makes tho in terms of required strength) or if it was mostly just my technique that's lacking which prevents me from swinging it on serve as freely.

All technique !!!
You get these scrawny azz girly boys serving 110 because of technique
 

FiReFTW

Legend
But bird arms

Yeah in my theory its better to have skinny arms, strong shoulders tho, you can accelerate a lighter arm much faster than a very heavy one, and the racquet on top of the arm has the same weight, so accelerating it faster is more benefitial hehe.
 

SystemicAnomaly

Bionic Poster
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Chas Tennis

G.O.A.T.
All muscle shortening forces are developed in the sarcomere.


1) Titin
original-1534950199.gif


This animation represents Titin in the muscle sarcomere, blue. Some forces are produced by elastic Titin, a giant molecule. The Titin forces are called 'Passive Forces'


2) Actin & Myosin (Titin not shown)

LateObviousAmericanpainthorse-small.gif


Better known and understood shortening forces are produced by other structures in the sarcomere called Actin and Myosin. The Actin & Myosin forces are called 'Active Forces'. Nerve signals release calcium ions that cause the Myosin to reach over to the Actin, form 'cross bridges', and cause muscle shortening.


Sarcomeres are the microscopic engines of muscle motion. Both the characteristics and limitations of the Titin and of the Actin & Myosin are observed in muscle motion. In 2019 not all features of muscle movement are well understood. Especially the features of Titin are curently being researched and discovered.

The answer to the OP is in the use and capabilities of Titin. The use involves stretching muscles and their Titin and then using stretched muscles to strike the ball at high speed. The mix of Titin vs Actin & Myosin vs time during tennis strokes is not well known.

1) Look at the mechanisms of Titin - do they resemble the rubber in a sling shot?

2) Look at the mechanisms of Actin & Myosin - do they resemble a caterpillar walking?

These two very different mechanisms will have different speeds for shortening the sarcomere.

Which mechanism would you think has the fastest maximum speed of sarcomere and muscle shortening?

----------------------------------------------------------------------------------------------------------------------------------------------------------------------

Complete Sarcomeres with Actin, Myosin and Titin as they contract and are stretched by external forces.
sm.titin.gif
 
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zaph

Professional
Your body will ultimately be a limiting factor on max service power. I am 5' 6" and lightweight, there is no way I can match the service power of someone who 6' 4" and 200 pounds plus.

Saying that, I have noticed that tall guys and big guys tend to have poor service techniques. They can get away with muscling the ball when they first learn to play and their height means they can get away with suspect services techniques. If I hit the serve the same way, I would constantly double fault.

So they can end up a situation were there serve doesn't really improve. Good technique isn't about the serve you can hit now, it is about giving yourself the opportunity to improve as your progress.
 

Crocodile

G.O.A.T.
Over 50 percent of service speed comes from having a fast arm . That being said, having the appropriate kinetic chain of movement is essential for correct technique.
 

ChaelAZ

G.O.A.T.
Watch pros warming up serves. They hit 90's without even bending legs much or any of the "power" they use in normal serves. It's more about technique/timing, then the extra pop from strength.
 

Chas Tennis

G.O.A.T.
Over 50 percent of service speed comes from having a fast arm . That being said, having the appropriate kinetic chain of movement is essential for correct technique.

Could you explain how the Kinetic Chain Concept deals with stretched muscles and the Stetch Shorten Cycle? For example, how is the elastic energy stored in the stretched muscles that perform ISR dealt with?

[ ISR - internal shoulder rotation, a defined joint motion. Called medial shoulder rotation in much of the world. ]

There is definitely a sequence but
1) Is it a sequence of body parts (or segments) building speeds from one segment to another? The Kinetic Chain Concept? Wouldn't that be all body parts with only speeds or kinetic energies?
2) Or is it a sequence of body motions that both build speeds and stretch muscles so that both kinetic energy from speed and potential energy stored in stretched muscles is involved.

Is there a Kinetic Chain Concept (even the name leaves out Potential Energy) reference for tennis strokes that describes the part played by stretched muscles?

Does the poor name, "Kinetic Chain", mislead people?

What is a "fast arm" and why is it fast?
 
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Boubi

Professional
So I've played with the RF97 for the past 2-3 years. My ground strokes with it are fine but my serve has always been a bit lacking. Then I recently tried out a lighter racket, the Clash 98 and I suddenly felt like my serves were a lot better since I felt like I could swing the racket faster. I feel like decrease in weight was the reason that my serve was faster. Which made me wonder, do I just need to get stronger so that I can serve with the RF97 better, (I do question how much difference a 31 gram diff makes tho in terms of required strength) or if it was mostly just my technique that's lacking which prevents me from swinging it on serve as freely.
Tennis is physics in application => you have to work on your technique (all shots)
 

BetaServe

Professional
Not only power, but height and arm length also play a big role:



Raonic looks like a lion and the others look like cats
 
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Crocodile

G.O.A.T.
Could you explain how the Kinetic Chain Concept deals with stretched muscles and the Stetch Shorten Cycle? For example, how is the elastic energy stored in the stretched muscles that perform ISR dealt with?

[ ISR - internal shoulder rotation, a defined joint motion. Called medial shoulder rotation in much of the world. ]

There is definitely a sequence but
1) Is it a sequence of body parts (or segments) building speeds from one segment to another? The Kinetic Chain Concept? Wouldn't that be all body parts with only speeds or kinetic energies?
2) Or is it a sequence of body motions that both build speeds and stretch muscles so that both kinetic energy from speed and potential energy stored in stretched muscles is involved.

Is there a Kinetic Chain Concept (even the name leaves out Potential Energy) reference for tennis strokes that describes the part played by stretched muscles?

Does the poor name, "Kinetic Chain", mislead people?

What is a "fast arm" and why is it fast?
My understanding is that the kinetic chain is a sequence of movement that requires the following principles to adhere to which includes:
Balance
Inertia
Opposite force
Momentum
Elastic energy
Coordination
It is these principles that determine how kinetic chain happens. Saying this, the kinetic chain can be observed and faults identified by the nature of chain that a player exhibits. For example some of the faults we find include:
1. Omitting part of the chain
2. Doing the chain in wrong order
3. Over doing or under doing a part of the chain
4. Doing a segment either too quickly or slowly which is what many refer to as timing.

A fast arm is what many refer to what should happen as a result of correct kinetic chain which adheres to the bio mechanical principles that I have mentioned. Hope this helps. Swing me another question if you want to. Cheers
 

Chas Tennis

G.O.A.T.
My understanding is that the kinetic chain is a sequence of movement that requires the following principles to adhere to which includes:
Balance
Inertia
Opposite force
Momentum
Elastic energy
Coordination
It is these principles that determine how kinetic chain happens. Saying this, the kinetic chain can be observed and faults identified by the nature of chain that a player exhibits. For example some of the faults we find include:
1. Omitting part of the chain
2. Doing the chain in wrong order
3. Over doing or under doing a part of the chain
4. Doing a segment either too quickly or slowly which is what many refer to as timing.

A fast arm is what many refer to what should happen as a result of correct kinetic chain which adheres to the bio mechanical principles that I have mentioned. Hope this helps. Swing me another question if you want to. Cheers

Do you have a link to a reference that explains how the Kinetic Chain's segments are using elastic energy?

In biomechanics and kinesiology the stretch shorten cycle is considered and not hidden.
 

SystemicAnomaly

Bionic Poster
My understanding is that the kinetic chain is a sequence of movement that requires the following principles to adhere to which includes:
Balance
Inertia
Opposite force
Momentum
Elastic energy
Coordination
It is these principles that determine how kinetic chain happens. Saying this, the kinetic chain can be observed and faults identified by the nature of chain that a player exhibits. For example some of the faults we find include:
1. Omitting part of the chain
2. Doing the chain in wrong order
3. Over doing or under doing a part of the chain
4. Doing a segment either too quickly or slowly which is what many refer to as timing.

A fast arm is what many refer to what should happen as a result of correct kinetic chain which adheres to the bio mechanical principles that I have mentioned. Hope this helps. Swing me another question if you want to. Cheers
Chas appears to have an issue with the KC model, particularly as it applies to the serve. I think he believes that a simple KC does not explain how leg drive affects ESR. Also appears to believe that SSC is incompatible with the KC. I do not share his concerns.

http://www.golfloopy.com/stretch-shortening-cycle-ssc/

https://www.aspetar.com/journal/viewarticle.aspx?id=198#.XX9m-6jYqzw
20141026124940.png
 
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SystemicAnomaly

Bionic Poster
Do you have a link to a reference that explains how the Kinetic Chain's segments are using elastic energy?

In biomechanics and kinesiology the stretch shorten cycle is considered and not hidden.
Models, like the KC model, do not necessarily tell us all the nitty-gritty details. They may often present more of a general overview. I believe we see this with climate models and various physics models. This does not invalidate the usefulness of these models.
 

Chas Tennis

G.O.A.T.
Models, like the KC model, do not necessarily tell us all the nitty-gritty details. They may often present more of a general overview. I believe we see this with climate models and various physics models. This does not invalidate the usefulness of these models.

Chas appears to have an issue with the KC model, particularly as it applies to the serve. I think he believes that a simple KC does not explain how leg drive affects ESR. Also appears to believe that SSC is incompatible with the KC. I do not share his concerns.

http://www.golfloopy.com/stretch-shortening-cycle-ssc/

You are exactly right about the KC, leg thrust and ESR. I think that is a clear illustration of how the KC fails. A service motion uses several sub-motions during the serve to force ESR and that stretches ISR muscles. Lets say that we are interested in leg thrust to jump and how that might affect ESR and stretch the ISR muscles. The legs straighten and that raises the body and accelerates the shoulder mass up. If the elbow is at a right angle and the forearm and racket are up and tilted back, forearm & racket inertia and leg thrust forces ESR and stretches ISR muscles. The leg thrust causes the ESR at a distance from the pelvis. The trunk is massive and moves up slowly. I see clear muscle stretching but I don't see segments speeding up between the pelvis and shoulder. It looks as if the abdomen were a length of wood between the pelvis and shoulder, there could have been ISR muscle stretching just because the shoulder mass was accelerated up. Elastic energy stored for the shoulder joint without speeding segments passing it up. I believe that using biomechanics, kinesiology, the stretch shorten cycle, and other principles - in particular considering the energy stored in stretched muscles - makes more sense.

In addition, the researchers that confirmed ISR, attacked the way the Kinetic Chain had missed the single joint motion, ISR, that contributed the most to racket head speed at the instant of impact. The KC missed that for decades. These publications started in 1995 pointing out specifically that the KC missed rotation of the long axis of the upper arm. Those are better arguments than I have and they emphasize the 'rotation of the long axis' - ISR. (Even if there still are some questions, that I recently learned about, on the accuracy of some of those early measurements.) I agree with the issue that Marshall and Elliott had with the Kinetic Chain.

Do you disagree with the Marshall and Elliott publication from 2000?

I believe that this situation exists because we can see segments swinging in high speed videos but it is more difficult to see the upper arm axially rotating but not going anywhere. It is also very difficult to see stretched muscles and especially those muscles that are stretched for the long axis rotation of the upper arm. Tennis strokes are viewed in biomechanics as closely associated with the stretch shorten cycle.


-----------------------------------------------------------------------------------------------------------------------------
Did you see this excellent and detailed video analysis video on the forehand in another thread? The KC is discussed and there are many good points. But the stretch shorten cycle, important for the stretch shorten cycles of abdominal muscles, was not mentioned during the stroke analysis. (It was mentioned once after the analysis.)
 
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Boubi

Professional
My understanding is that the kinetic chain is a sequence of movement that requires the following principles to adhere to which includes:
Balance
Inertia
Opposite force
Momentum
Elastic energy
Coordination
It is these principles that determine how kinetic chain happens. Saying this, the kinetic chain can be observed and faults identified by the nature of chain that a player exhibits. For example some of the faults we find include:
1. Omitting part of the chain
2. Doing the chain in wrong order
3. Over doing or under doing a part of the chain
4. Doing a segment either too quickly or slowly which is what many refer to as timing.

A fast arm is what many refer to what should happen as a result of correct kinetic chain which adheres to the bio mechanical principles that I have mentioned. Hope this helps. Swing me another question if you want to. Cheers
There is no such thing as ''kinetic chain''
 

Kevo

Legend
In addition, the researchers that confirmed ISR, attacked the way the Kinetic Chain had missed the single joint motion, ISR, that contributed the most to racket head speed at the instant of impact. The KC missed that for decades. These publications started in 1995 pointing out specifically that the KC missed rotation of the long axis of the upper arm. Those are better arguments than I have and they emphasize the 'rotation of the long axis' - ISR. (Even if there still are some questions, that I recently learned about, on the accuracy of some of those early measurements.) I agree with the issue that Marshall and Elliott had with the Kinetic Chain.

Do you disagree with the Marshall and Elliott publication from 2000?

I believe that this situation exists because we can see segments swinging in high speed videos but it is more difficult to see the upper arm axially rotating but not going anywhere. It is also very difficult to see stretched muscles and especially those muscles that are stretched for the long axis rotation of the upper arm. Tennis strokes are viewed in biomechanics as closely associated with the stretch shorten cycle.

I don't think the KC missed anything. It's a conceptualization of what's happening. It's not a mathematical simulation that precisely predicts how fast someone with throw, kick, or serve if you put in their height and weight. To be fair, maybe this is just semantics and such, but people miss things and concepts can be poorly conceived, but the KC as a concept still makes sense and is a good model for understanding even if those using it failed to fully describe certain techniques.

Furthermore, I think at least with Tennis and other racquet sports, it would seem to be an egregious error for someone to miss arm rotation since it clearly provides a leverage advantage with a racquet hanging out of your hand and can be clearly seen on many old videos and has been used for who knows how many players since the early 1900s. You can clearly see it in Wimbledon videos from the 1930s. It was certainly published in Tennis magazine at least by 1993 as that is when I learned about it and the lightbulb finally went off for me on serve.
 

AlexSV

Semi-Pro
It's probably closer to 10% for strength / technique. 90% for some intangible mental aspect that allows you to use the technique and strength.
 
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