The arm is not dragging by the body

[ho]

Originally Posted by user92626

Killed by enormous speed?

What kind of logics is this?


If you got killed from that, it would likely be from slamming your face on the ground or something similar.

I'm sorry, if you slam on something

[ho]

Originally Posted by toly

I answered on all your claims in post #18, except the idea “… the prolongation of contact time”.
jumpulse.com tried very hard to sell this idea, but without any success. IMO this is nonsense, absurd etc. Even Oscar Wegner quit taking about that.

Ball is a soft object, on impact it deformed, the harder you hit, the more it deformed, the more it deformed, the more it stay on the string bed, the more it stay on string bed, the more it bounce out.
Oscar is a tennis coach, he is not a scientist.
Just hit the heck out of the ball, arm and body as one unit, you will have such an easy time on the court.

[toly]

Originally Posted by maxpotapov

As I understood Albesca, it's not just arithmetic sum, but there's a progression in how parts align and interact to create optimal conditions for fastest racquet acceleration at the point of impact.

I would also argue, that even if PROPER coordination/rotation of lower/upper body contributes only 15% to the racquet speed, LACK THEREOF might cause a 40% slow down.

Yes, I agree with you.

The problem is that we don’t know ideal procedure on how to hit FH. After 30 years from now, current FH technique probably would be ridiculous. But, at least we should try to understand what is really very important and what is not.

For example, Lock&Roll coach emphasizes too much importance of the hips and body rotation. But, when he demonstrates FH, his arm and its parts (including wrist) are very active. That’s why I dislike his monkey’s drum idea. IMO he puts wrong accents in his explanations.

[Dellon]

Interesting study I found ... compares the major differences between novice and expert players. the ones marked with an * shows significant differences between the two: upper trunk and wrist

http://www.sph.umd.edu/KNES/faculty/...s/46%20-50.pdf

[Dellon]

and one more a bit more comprehensive

http://www.jssm.org/vol9/n4/15/v9n4-15pdf.pdf

[Dellon]

to me this is the ultimate position in tennis with your upper body facing the net ... when I hit a forehand I always think I'm hitting it with my chest and when I do that everyhting else works perfectly.

[IMG]H:\My Pictures\forehand.jpeg[/IMG]

[Dellon]

how do I attach a picture?

[Dellon]

this is what I'm thinking that I am when I rotate my body and hit a forehand ...teh top handle is my shoulders and chest) ... just imagine it has a spring at the bottom ... you twist it to the right and then release it ... no hip rotation no other things ... they happen naturally as they all conect you to the ground

http://www.advdesigns.com/ro14insptdr.html

[toly]

Originally Posted by ho

Ball is a soft object, on impact it deformed, the harder you hit, the more it deformed, the more it deformed, the more it stay on the string bed, the more it stay on string bed, the more it bounce out.

The harder we hit the ball, the more it is deformed and damaged. The damage of the ball is essential.
If we hit ball with racquet speed 1 mph, coefficient of restitution (if I remember correctly) will be around 70%. If racquet speed is 80 mph, this coefficient is just 30%. Thus, scientific data disagree with your statement.

Originally Posted by ho

Just hit the heck out of the ball, arm and body as one unit, you will have such an easy time on the court.

If we rotate fixed passive arm and body as one unit, we will produce around 15% of the possible maximum of the racquet speed. See please Elliot data.

[maxpotapov]

Originally Posted by toly

For example, Lock&Roll coach emphasizes too much importance of the hips and body rotation. But, when he demonstrates FH, his arm and its parts (including wrist) are very active. That’s why I dislike his monkey’s drum idea. IMO he puts wrong accents in his explanations.

That's most likely due to assumption, that novice/recreational players use their arm only, and hips/body rotation is counter intuitive and thus must be overemphasized.

I personally think it's a good way to start, as developing proper fundamentals is difficult (counter intuitive, energy inefficient) yet essential. But once body starts moving and working, it's time to explore those 85% that accelerate racquet head through the contact point.

[albesca]

Originally Posted by toly

..For example, Lock&Roll coach emphasizes too much importance of the hips and body rotation. But, when he demonstrates FH, his arm and its parts (including wrist) are very active. That’s why I dislike his monkey’s drum idea. IMO he puts wrong accents in his explanations.

Yes Toly, i'm watched along L&R forehand video and I have come to your own conclusions !!

[albesca]

Originally Posted by Dellon

how do I attach a picture?

Thank you Dellon for ur contribution.

You would upload ur photo up on a image storage service.. after the uploading, get the pic link and insert it with the pic button in post editor.

I like "Google Photos - Picasa Web Albums" but if you search "image hosting" on google .. you can find thousands other for free.

Ciao
Al

[rkelley]

Originally Posted by toly

For example, Lock&Roll coach emphasizes too much importance of the hips and body rotation. But, when he demonstrates FH, his arm and its parts (including wrist) are very active. That’s why I dislike his monkey’s drum idea. IMO he puts wrong accents in his explanations.

Originally Posted by albesca

Yes Toly, i'm watched along L&R forehand video and I have come to your own conclusions !!

How does the arm and wrist being active negate the assertion that the power is coming not from the arm but from the legs and core? The arm is of course active because it's ultimately the thing that is being whipped by the legs and the body. And again, the fact that the arm is whipped into the ball doesn't mean that the muscles in the arm aren't being used. They most definitely are being used, but more like a spring.

Also you do realize that the Lock and Roll guy is a pretty accomplished player and coach? I've personally found his videos to be very helpful.

Just go grab a tennis racquet and a ball, go out to your favorite wall, and hit a few. Serves, ground strokes and overheads all work on the principle that larger muscles groups unload energy into whipping the racquet into the ball. Actually most sports that involve throwing and hitting things use this concept. Just throw a ball - same idea. Your legs and core whip your arm around to throw.

[ho]

Originally Posted by toly

The harder we hit the ball, the more it is deformed and damaged. The damage of the ball is essential.
If we hit ball with racquet speed 1 mph, coefficient of restitution (if I remember correctly) will be around 70%. If racquet speed is 80 mph, this coefficient is just 30%. Thus, scientific data disagree with your statement.

Damaging ???
The harder we compress the ball, the more it will bounce out, if you do not comprehend this, and show scientific data disagree with me, I quit.

Originally Posted by toly

If we rotate fixed passive arm and body as one unit, we will produce around 15% of the possible maximum of the racquet speed. See please Elliot data.

Sure, but the mass behind it as 10 time larger. result in the ball speed will be more.
Think, Toly, think.

[toly]

Originally Posted by ho

Damaging ???
The harder we compress the ball, the more it will bounce out, if you do not comprehend this, and show scientific data disagree with me, I quit.

The racquet can really hurt a tennis ball and not just it. See for example Youzhny, PhD scientific experiment http://www.youtube.com/watch?v=fi-CgSO9Evw&ob=av3e around 0:40.

Kid experiment in video (not scientific?), http://www.youtube.com/watch?v=ym3wczI0s84, shows that ball bounce high is not directly proportional drop high. The physic low is: The greater the height of the incident ball, the less the efficiency rebound (more damage).

Originally Posted by ho

Sure, but the mass behind it as 10 time larger. result in the ball speed will be more.
Think, Toly, think.

About this matter, see please my posts http://tt.tennis-warehouse.com/showt...80#post5895380 and http://tt.tennis-warehouse.com/showt...60#post5892760.

[albesca]

Originally Posted by rkelley

How does the arm and wrist being active negate the assertion that the power is coming not from the arm but from the legs and core? The arm is of course active because it's ultimately the thing that is being whipped by the legs and the body. And again, the fact that the arm is whipped into the ball doesn't mean that the muscles in the arm aren't being used. They most definitely are being used, but more like a spring.

Also you do realize that the Lock and Roll guy is a pretty accomplished player and coach? I've personally found his videos to be very helpful.

Just go grab a tennis racquet and a ball, go out to your favorite wall, and hit a few. Serves, ground strokes and overheads all work on the principle that larger muscles groups unload energy into whipping the racquet into the ball. Actually most sports that involve throwing and hitting things use this concept. Just throw a ball - same idea. Your legs and core whip your arm around to throw.

I'm not here to prove anything to anyone. I say only that for years I left the control of my forehand to the trunk and legs ..and I'm still waiting yet to see a decent ball come out from my strings (a bit of spin and a bit of speed.. don't pretend so much).

Only when I moved my attention to the speed of the arm in the forward swing the level of my forehand has changed, that doesn't mean i don't use legs and trunk .. only i don't think at them, I know my lower body is loaded and that's all, so I cannot do other then to conclude that the arm is crucial in the production of ball speed ... crucial.. and the matter the arm go fast.. are we! Kinetic chain does anything by itself. The lines attached in the monkey drum don't impact a mass .. we need to do it, that changes everything .. dragging the arm like a monkey drum is not enough and the nice R&L guy would spend some words in why and what he does with his arm too.. because, by me, it isn't secondary.

But mine is only very modest opinion of a tennis fan, so take it for what it is.

[user92626]

What the heck are you guys arguing about?

Just keep it simple. Use your arm, relaxed, and whip the ball hard. Get your body involved and your legs help with the body turning so the arm can swing a larger range/path.

Using your arm only will give you a very short range and you will cramp the muscles together. That's all.

[SystemicAnomaly]

Originally Posted by maxpotapov

... it's not just arithmetic sum, but there's a progression in how parts align and interact to create optimal conditions for fastest racquet acceleration at the point of impact.

I would also argue, that even if PROPER coordination/rotation of lower/upper body contributes only 15% to the racquet speed, LACK THEREOF might cause a 40% slow down.

Originally Posted by toly

... I think that 15% contribution to the racquet speed is not very important for the reason that we have to waste a lot of energy to create fast rotation of 130 - 200 pounds body. IMO it is better first to concentrate on arm actions and then on the body. The arm is much more important. In tennis everything is important, however with varying degrees of importance.

Don't really know exactly what Brian Elliot means by this 15% contribution. However, what I've read of his published study, he seems to indicate that a full well-coordinated kinetic chain is important to high level tennis strokes. In light of this, the 15% figure appears to be rather misleading. It suggests to some that the contributions from the legs, hips, core and trunk are not all that important. I do not believe that this is the case. maxpotapov's statements above could have some merit.

If the contributions from the links are really not all that important, then why do high level players "waste a lot of energy" employing those links on most of their shots? Often, they are playing or practicing for 3-5 hours or more a day. It would seem foolish for them to "waste energy" for an extended period of time if the returns are trivial or unimportant.

It is my belief that using the legs, hips, torso, etc reduces stress to the shoulder and rotator groups. We transfer "energy" to the shoulder and arm from the previous links rather than have the shoulder (and arm) generate it all own its own. The leg muscles are much stronger that the shoulder and arm muscles. The legs, hips and torso also represent larger masses (with greater rotational inertia) than the shoulder/arm and racket. So when we transfer the energy from those larger parts to the shoulder, it allows the arms to accelerate more easily (with less stress).

I am keenly aware of the stresses in my own shoulder. For the past few years I've had somewhat limited shoulder function (from an old volleyball injury to the rotator groups -- some 20 yrs ago). If I prepare late for a shot and try to rely solely on my shoulder/rotators to swing my racket, I experience significant pain. However, when I employ my legs, hips and torso, I can get my shoulder/arm moving quite fast without pain.
.

[bhupaes]

IMO, maxpotapov is 100% correct. The work done by the legs and torso loads up the muscles of the lagging arm/shoulder, and this energy is released when the arm fires. I believe there are studies that show that stretched muscles are able to generate more force/speed when they contract. Ergo, factoring the legs/body out of the equation will have a big impact on the final power delivered.

Of course, the arm muscles are very active. My contention is that the more we are able to let the arm relax by using the legs/body, the more control we will get. If the arm muscles are 100% active, yeah, there will be enough power to launch the ball to the moon, but control will go down the toilet.

Also, IMO, there are many ways to hit the forehand (or backhand). This variation may be due to stylistic preferences, and/or game situations. Thus I would say that it is not realistic to assume that a particular muscle group always contributes a fixed percentage of power for a specific stroke such as the forehand.

[bhupaes]

One clarification on my point of view - when I say that legs and bodies should be used to the maximum extent, I am not recommending doing upper body rotation that resembles a U-turn! Far from it - in fact, I am not a big believer in UBR. I don't believe that the rotational speed of the upper body is a big contributor to racquet head speed. I don't believe UBR is done for its additive effect to racquet head speed. However, the right amount of upper body turn is essential to properly load/stretch the appropriate muscles. Similar reasoning applies to leg use. Some people, the pros in particular, are able to get a lot out of UBR and legs. Some of us sedentary and stiff types simply will not be able to get as much, but we should aim to maximize what we do get.

Okay, I've said everything I know now, right or wrong...