confused w/ the term "MTM"

[boramiNYC]

shuresh u got that exactly right. the centripetal force is the basis of swinging of human arm. pulling must be toward the center. determining the center is no simple matter however but fun topic for discussion.

[sureshs]

Originally Posted by boramiNYC

shuresh u got that exactly right. the centripetal force is the basis of swinging of human arm. pulling must be toward the center. determining the center is no simple matter however but fun topic for discussion.

Bhupaes confused the centripetal force with pulling to the right because he observed the tip of the hand moving to the left when the racket tip was moving to the right (due to wrist bend, etc). Later in the arc, the hand and the racket could both be moving to the right. So, focusing on one part of the arc does not provide the right picture. There needs to be a centrally directed force in any curvilinear motion, and the direction of the force changes from instant to instant.

[bhupaes]

Originally Posted by sureshs

Bhupaes confused the centripetal force with pulling to the right because he observed the tip of the hand moving to the left when the racket tip was moving to the right (due to wrist bend, etc). Later in the arc, the hand and the racket could both be moving to the right. So, focusing on one part of the arc does not provide the right picture. There needs to be a centrally directed force in any curvilinear motion, and the direction of the force changes from instant to instant.

No, I didn't confuse anything. If one were only depending on centripetal force, any muscle not used for gripping the racquet will be passive. Try swinging like that and see where the ball goes.

I will stick with everything I've said in this thread - let's just agree to disagree.

[sureshs]

Originally Posted by tennisfan69

that is up for discussion. but from analyzing various videos like this of top players, the question to be answered is if the pulling across is a deliberate action or it is a consequence of the swing.
the concept of hitting thru 3-5 balls as being coached at where my sons get coached, i am interested from experts here is it correct. so i dont have any conclusion, but more questions.

Is he hitting the ball solidly when he wants to put pace on it? Is he generating the pace you want to see? Is he generating the spin you want to see? Is he blending pace and spin into his shots at the level of his peers?

The hitting through 3 balls advice is mostly for beginners and adults, who are tentative with their shots. It becomes a bad reinforcing habit as they become even more tentative in a match. Eventually, people should evolve to learn how to swing the racket for varying amounts of pace and spin, and for different target areas, as all juniors do.

In the simplest example, I have observed a coach correct the swing in this fashion: the junior was hitting too closed and with too much spin and the ball was landing short. He simply told him that to hit beyond the service line was the goal. The junior achieved that by blending in more linear momentum. In another case, a junior was hitting backhands hard but long. The coach fed him ball after ball with the goal of keeping it in, and the junior learnt how much spin to add in that situation.

There are many arguments here which are based on strawman examples and pushing some system. Life is much simpler in reality.

[bhupaes]

^^^ One more thing, sureshs. The pulling in action has an additional side effect - it helps release the wrist forward thus adding more to RHS, assuming the wrist is held loose, and the player has good timing.

There, we should be in 100% disagreement now!

[sureshs]

Originally Posted by bhupaes

No, I didn't confuse anything. If one were only depending on centripetal force, any muscle not used for gripping the racquet will be passive. Try swinging like that and see where the ball goes.

I will stick with everything I've said in this thread - let's just agree to disagree.

It is not just centripetal force, there is also linear acceleration that has to be supplied, the path is not perfectly circular, gravity is involved, etc. Obviously twirling a stone on a string is not like hitting the tennis ball. For example, I have explained many times why the two-pendulum model of passive swing is wrong and led to wrong calculations.

[sureshs]

Originally Posted by bhupaes

^^^ One more thing, sureshs. The pulling in action has an additional side effect - it helps release the wrist forward thus adding more to RHS, assuming the wrist is held loose, and the player has good timing.

There, we should be in 100% disagreement now!

There is definitely conscious action, it is not like Nadal showed up and was swinging his hand loosely for the heck of it. But the major part of the motion is due to maintaining the arc. It is not a matter of pulling the racket to the right. That is not the apt way to describe what is going on. Just like the idea of pulling across has been completely debunked. It would look like that video mentioned earlier with the person almost losing balance.

[boramiNYC]

Originally Posted by bhupaes

No, I didn't confuse anything. If one were only depending on centripetal force, any muscle not used for gripping the racquet will be passive. Try swinging like that and see where the ball goes.

I will stick with everything I've said in this thread - let's just agree to disagree.

doesn't that passiveness explain alot of straight arm or whippy crazy rhs for the high level tennis?

[sureshs]

Originally Posted by boramiNYC

doesn't that passiveness explain alot of straight arm or whippy crazy rhs for the high level tennis?

Yes many parts should be laid back and passive not tight.

Look, there is definitely intent behind a swing in tennis. Nadal definitely does not want the racket to keep moving to the left. In that sense, he is pulling it to the right, but that does not seem the appropriate way to explain this. There are also flick shots where you can see pros deliberately manipulating the racket with the wrist in isolation from the rest of the swing.

[bhupaes]

Originally Posted by boramiNYC

doesn't that passiveness explain alot of straight arm or whippy crazy rhs for the high level tennis?

Well, I guess I should have used the word "dead" instead of "passive" in my earlier post! IMO, you are right in that a lot of the movements are passive in that energy is released rather than created. Thus I would advocate having a loose arm structure in general. However, "passive" does not mean no activity ("dead"). Energy is stored during the eccentric contraction phase in many arm muscles for generating power and spin, and some muscles are very active (especially for control related actions). It is too complex to lend itself to a simplistic analysis or description, IMO. I can imagine and feel what happens, but far be it from me to try to quantify it, or even describe it accurately!

[toly]

Originally Posted by bhupaes

This is a crucial observation - that the tip of the racquet is actually moving to the left, while the hand is actually pulling the racquet to the right.

What is happening is that Nadal is rotating his upper arm, as in internal shoulder rotation. This causes the racquet that is pointing downwards to become more horizontal, and the tip moves outwards faster than the hand is moving in. This is the real effect of pulling across - it whips the racquet outwards, forwards and upwards, due to the leverage of the arm structure. This is the purpose of pulling in - it is not for adding sidespin.

In general, the racquet is pulled in using two movements - internal shoulder rotation, and the biceps. Those with bent arm forehands use the biceps more than those who use straight arms. Nadal clearly is an extreme sort of guy , and seems to be using only ISR.

Sidespin can happen, however. If the grip is more western, the pulling in of the racquet causes the head to rise up more vertically, which is what this particular stroke sequence is showing. If the grip is more eastern, I think there will be more forward and sideways movement, as I suspect happens in Federer's stroke.

One more thing - the pulling in starts a little before contact. It is a deliberate move, and not something that happens because the arm is moving in a circle.

You can do shadow swings and experience what happens first hand... that's how I came to my conclusions.

The Oscar Wegner in video http://www.youtube.com/watch?v=MxUPDHegz98 around 2.50 demonstrates across motion and side spin. In our example Nadal create mostly topspin, see original video. You also can ask JY about sidespin in this particular Nadal FH video.

Wegner also said, around 6.30, that Federer slowly goes to the ball then all acceleration occurs sideway. IMO there is no correlation among his explanations and videos of Federer and Nadal FH.

Tell me please, in what frame exactly Nadal begins sideway acceleration.

When Nadal rotates the arm around shoulder, he creates centrifugal force which has normal component to the racquet string plane. This force normal component (motion dependent torque) automatically rotates the racquet in clockwise direction, see Rod Cross article http://www.racquetsportsindustry.com...the_serve.html.
This normal component is function of angle (ϕ) between arm and racquet. If ϕ=0, this component is zero. This normal component is also function of arm angular acceleration. The more we accelerate angular rotation the less is motion dependent torque.

On other hand, Nadal applies extremely hard arm pronation/ISR. This is also angular rotation, which also creates its own centrifugal force and motion dependent torque. Rod Cross completely ignored this fact.

Moreover, this motion dependent torque pushes the hand to rotate the racquet in clockwise direction, opposite to the torque created by arm rotation. So, there is no automatic motion dependent whip effect. I believe, Nadal creates very fast wrist/hand swing, by using extremely actively hand’s (or whatever) muscles.
I think you still remember the physics, you can get it.

[bhupaes]

Originally Posted by toly

The Oscar Wegner in video http://www.youtube.com/watch?v=MxUPDHegz98 around 2.50 demonstrates across motion and side spin. In our example Nadal create mostly topspin, see original video. You also can ask JY about sidespin in this particular Nadal FH video.

Well, he's talking about Federer - and I would expect Federer to produce more sidespin. Again, remember, you have shown us one example of Nadal. I have seen him hit vicious sidespin on many occasions. But I still maintain the sidespin is a side effect of the technique used, and may or may not always happen.

Wegner also said, around 6.30, that Federer slowly goes to the ball then all acceleration occurs sideway. IMO there is no correlation among his explanations and videos of Federer and Nadal FH.

I think you've misunderstood. Oscar doesn't say all acceleration is sideways. He only points out that there is a strong sideways pull near the point of contact. Also, "slowly" is relative - all it means is that in the initial phase, RHS is considerably slower than the contact phase, as far as I am concerned.

Tell me please, in what frame exactly Nadal begins sideway acceleration.

In the picture I included in my post, assuming each overlay is a frame, probably around the 18th frame.

When Nadal rotates the arm around shoulder, he creates centrifugal force which has normal component to the racquet string plane. This force normal component (motion dependent torque) automatically rotates the racquet in clockwise direction, see Rod Cross article http://www.racquetsportsindustry.com...the_serve.html.
This normal component is function of angle (ϕ) between arm and racquet. If ϕ=0, this component is zero. This normal component is also function of arm angular acceleration. The more we accelerate angular rotation the less is motion dependent torque.

Okay...

On other hand, Nadal applies extremely hard arm pronation/ISR. This is also angular rotation, which also creates its own centrifugal force and motion dependent torque. Rod Cross completely ignored this fact.

Moreover, this motion dependent torque pushes the hand to rotate the racquet in clockwise direction, opposite to the torque created by arm rotation. So, there is no automatic motion dependent whip effect. I believe, Nadal creates very fast wrist/hand swing, by using extremely actively hand’s (or whatever) muscles.
I think you still remember the physics, you can get it.

Ah, there you go again, toly! We've hit on our fundamental area of disagreement one more time... passive vs. active wrist! Unfortunately, neither you nor I can prove our points from photographs!

Let me also point out that in the video of Oscar you have posted, he shows a combination of upper arm rotation and biceps action when he is pulling the racquet in. I think this is natural for most people, and we have an extreme example in Nadal.

[5263]

Originally Posted by sureshs

Your claims about a deliberate across swing have been shown to be wrong when the intention is to hit solidly and not in a grazing fashion. It is due to body rotation into the ball. The claim of an abrupt pull back before contact has been shown to be wrong.

I don't know where you get "abrupt pull back"; is that your words?
I don't know where you get "deliberate across" swing; is that yours?

In MTM we teach to "pull up and across". We don't suggest that it be abrupt or
deliberate...only that you do it and anyone can see the best players do it.
It may need to be more deliberate till it becomes natural? can't say.
That is what is known as well as what has been clearly shown.
If you can't see it, maybe that accounts for the desperate need of help for your
Fh that you posted about.

[5263]

Originally Posted by bhupaes

Ah, there you go again, toly! We've hit on our fundamental area of disagreement one more time... passive vs. active wrist! Unfortunately, neither you nor I can prove our points from photographs!

Let me also point out that in the video of Oscar you have posted, he shows a combination of upper arm rotation and biceps action when he is pulling the racquet in. I think this is natural for most people, and we have an extreme example in Nadal.

bhupaes, sorry I don't believe toly was ever a serious engineer and clearly he
is very much a beginner in tennis. Any good engineer comes to things with an
open mind, seeing several possible solutions to a challenge, then works to pick
the best for the intended application. No respected engineer would take the
comments Oscar made about an I/O out of context to try to twist it and try to
make a bogus point on related to normal rally Fhs.

toly clearly has several ideas that he is
intent on proving, like the using muscles in the wrist (forearm) to get power,
along with some of his other ideas; BUT to the exclusion of other ideas that
also work,
and imo, work much better than his beginner approach. He acts as if he is
bringing something new to strokes, but with any experience at all, he would
see that his suggestions are like nearly every beginner shows up with for coaching.
And the reason they come for coaching is that those rookie ideas don't work for
hitting with power AND keeping it in the courts.

As an engineer myself, I realize his ideas can be a source of power, but so
far, I've never seen any player work them with even a basic level of consistency
required to do even avg in this game. I'm a good enough sport to acknowledge
that some player may come along and somehow change that, although I doubt it.
Notice the difference in yours and my recognition of what they have
to share concept wise, but just know we have been thru that and not seen it
successful, whereas they deny our very successful approach and try to somehow
put a square peg in a round hole to force their ideas into what they see despite the
vids and evidence.
Also notice toly never shows the swing "from contact on", which is where my
claims are demo'd and also avoids admitting the bigger spacing in his pics that
show accel into contact. And also never understands how the hand working
across in his pics leads is what the racket face will be doing thru contact and
beyond, while also talking of some garble about the clear and present side
aspect to the TS we have seen which is actual proof of side motion at contact.

[connico]

Originally Posted by 5263

In MTM we teach to "pull up and across". We don't suggest that it be abrupt or
deliberate...only that you do it and anyone can see the best players do it.
It may need to be more deliberate till it becomes natural? can't say.
That is what is known as well as what has been clearly shown.
If you can't see it, maybe that accounts for the desperate need of help for your
Fh that you posted about.

So your not teaching anything, you just describing how it should work. I can accept MTM if your not teaching to deliberately pull across the body and only describing a swing path.

I've always had issues with MTM because my impression from the videos and oscars comments is that that MTM teaches a deliberate pull across motion which I don't agree with.

In saying this, does MTM recognise that on a advance forehand pronation is key to efficient power and topspin?

[Frank Silbermann]

MTM stands for "Mary Tyler Moore."

[5263]

Originally Posted by connico

So your not teaching anything, you just describing how it should work. I can accept MTM if your not teaching to deliberately pull across the body and only describing a swing path.

I've always had issues with MTM because my impression from the videos and oscars comments is that that MTM teaches a deliberate pull across motion which I don't agree with.

In saying this, does MTM recognise that on a advance forehand pronation is key to efficient power and topspin?

To your 1st point, "deliberate" is not a term that I remember hearing or reading
from Oscar related to the strokes, but I'm not stating that it has not been used.
I just don't ever remember thinking of it that way. Our teaching does work on
developing feel for a path and normally little would be said, relying more on demonstration and
a couple of comments like "try this and see how that feels" coupled with a
demo of what to try or a simple suggestion. It's about trying to relate to the
student in a way that works for them. Maybe that is part of why it does not
translate well for some on this forum, while others get it straight away.

As to Pronation, again, that is not a term we would normally use, as most students
would not have a clue what it is. It even comes up as a spelling error on here and
is way easier to demo than to explain...especially with a Fh imo.
This is far from an optimal medium to share MTM, but so many have got it thru
the years from here just like I did, it would be a shame to get bullied off from helping so
many. My new 70 yr old student heard of MTM from debates much like these (not TT)
and called me for lessons to see what this uproar was all about, even though he
had played tennis his whole life. After each lesson he thanks me several times and
speaks of how he can't believe pros are still teaching the traditional way.
Thanks for your reasonable approach to things and use what works for you.
I'm happy that you are playing, traditional or modern and just am here for those looking
for an edge or to improve.

[JW10S]

Oh gee, look what I've missed, another obviously planted MTM thread. I'm not going to waste my time reading through all the posts but will answer the OP that MTM is just 1 of many, many, many, modern systems of teaching out there. MTMers will tell you anyone not teaching MTM is teaching traditonal, and anyone teaching modern tennis is using MTM, which is just not true. I'm a modern teacher (and so are the pros who work for me) and I work with current ATP, WTA and ITF players and use none of the MTM tenants I read about here. Don't be sucked into the 'it's either MTM or traditional' because that is nowhere close to the truth. It's just not that black and white.

[sureshs]

Originally Posted by toly

Wegner also said, around 6.30, that Federer slowly goes to the ball then all acceleration occurs sideway. IMO there is no correlation among his explanations and videos of Federer and Nadal FH.

It is a bunch of imaginary things. If people over-analyze something to show that they have a new insight, they come up with these kind of things. They look for intent where there isn't any. They try to artificially separate intent from flow to show that there is some value-add to their method. Many of these claims are of the wishy-washy kind and what we end up doing is trying to treat them rationally and then arguing among ourselves. This prolongs the thread and provides publicity. We are the ones who are being fooled.

[sureshs]

Originally Posted by JW10S

Oh gee, look what I've missed, another obviously planted MTM thread. I'm not going to waste my time reading through all the posts but will answer the OP that MTM is just 1 of many, many, many, modern systems of teaching out there. MTMers will tell you anyone not teaching MTM is teaching traditonal, and anyone teaching modern tennis is using MTM, which is just not true. I'm a modern teacher (and so are the pros who work for me) and I work with current ATP, WTA and ITF players and use none of the MTM tenants I read about here. Don't be sucked into the 'it's either MTM or traditional' because that is nowhere close to the truth. It's just not that black and white.

I also suspected a planted thread but did not want to mention it. When a new user pops up with the first question about this methodology, I was very suspicious. But I wanted to give him/her the benefit of the doubt.

In any case, you are absolutely correct. We are all suckers to constantly fall for this and for assuming that there is any rational basis for their claims.