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BU-Tennis
01-10-2009, 06:51 PM
Ok. So i was watching some slow motion video of pro serves. And the biggest thing that I noticed was how the so called "kinetic chain" is almost non existent. I was under the impression, and have told many people, that in order to serve well you have to fire the legs, hips, shoulders, arm, then wrist. However, I noticed that after the legs start to explode into the shot, the arm, torso, hips, and shoulders move at the same time. Check out the video below to see what I mean. While the kinetic chain sounds good I think it is nearly impossible to accomplish correctly. Not to mention, anytime I try it, my arm feels like its going to rip off. I think its important to notice how the body moves and rotates to add power and consistency to a serve but we can't forget that you still have to swing the racquet with the arm also.

http://www.youtube.com/watch?v=WWC1hcKBh4g&feature=related

SystemicAnomaly
01-10-2009, 08:04 PM
Not true. The kinetic chain most certainly does exist, and is very important, for an efficient, effective service motion. It seems that your understanding of the kinetic chain principle is flawed.

The chain consists of a sequence or pattern of overlapping links. This concept is also known as the kinetic-link principle or the linked system of transferring forces. A simple chain may consist of a simple series of overlapping actions -- a single action occurring & then concluding as another one starts up. We sometimes think of a kinetic chain in tennis as a sequence of events happening from the ground up.

However, the serve, as many other chains in tennis, are a bit more complex than this -- it is not a single simple chain of events. A number of actions occur in a complex pattern of parallell and sequential events.

Let's look at just a few segments of the service motion. Note that the legs are bending as the ball is tossed. The legs subsequently extend as the racket (head) drops behind the back. The legs should be fully extended (or nearly fully extended) as the arm and racket start their extension -- the upward swing of the racket head upr to contact the ball.

USTA Player Development - Technique: The Kinetic Chain (http://www.playerdevelopment.usta.com/content/fullstory.sps?iNewsid=114390&itype=7418)

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BU-Tennis
01-10-2009, 09:02 PM
I didn't say that the kinetic chain didn't exist. Just that it is a little more simple in execution than what was previously thought. It is mainly a subconscious motion. And i was mainly talking about the body involvement. the usta says the kinetic chain is the leg drive, torso rotation, upper arm elevation, forearm extension, and hand flexion. Some people add that the hips should fire before the shoulder. I mainly suggest that the torso and arms start moving at the same time, with the arm actually moving at a faster speed. When the rotation is complete the legs are fully extended, the chest is mostly open to the net, the upper arm is elevated, with the final part of the chain starting to occur. The new kinetic chain should merge trunk rotation and upper arm elevation into one movement, try to rotate your body without moving your arm, its impossible. People, like myself, who don't have access to high quality coaches and fancy facilities are left to discover tennis by themselves, and with the USTA and other people giving out advice that is too technically advanced for anyone to actually incorporate into their game is potentially hazardous. The kinetic chain, while it happens, is a natural development in the service motion and should not be forcibly incorporated.

WildVolley
01-10-2009, 09:24 PM
I too am a little confused by your post.

The first thing people are taught when learning the serve isn't the kinetic chain. I find it best to start with the proper grip and contact point and then work from there. I start beginners with a very short swing from the racket drop position and only later incorporate a full swing and the rest of the body.

I think the kinetic chain is a concept. The serve is a complex compound movement. How to maximize serve efficiency is a really a combination of art and science at this part. High speed video and computer modeling is giving us a better idea of how the best servers do what they do.

I think you can help train yourself using a video camera and slow motion video of good players. On the other hand, a good coach can help you recognize things that you are doing or not doing.

Almost all high level tennis occurs at a subconscious level with respect to stroke production, but that only develops out of a lot of conscious adjustments and repetition.

BU-Tennis
01-10-2009, 10:06 PM
I didn't say that the kinetic chain is the first thing taught. But when someone asks in a forum how to improve their serving technique the kinetic chain concept is usually one of the ideas presented.

Also, the main idea of the post is that the kinetic chain is flawed in its application. Although the body does move in this complex pattern, it is not a conscious effort by the player and never was even when first learning. To try and consciously coordinate these complex movements can result in poor form and injury.

I wanted to call attention to the fact that the arm starts its movement at the same time as the body and not just in a passive form. The arm must move into position at the same time as the body is rotating. Then, once they are in the hitting position, the elbow can straighten, the forearm can pronate, and the ball struck.

pierretennis
01-12-2009, 10:28 PM
BU- In France we realize that the serve is made up of rotations and linear movements. In America, they look purely at rotations, no? Maybe that is the flaw?

Pierre

BU-Tennis
01-12-2009, 11:01 PM
That is a good point pierre. I think the rotation of the body is sometimes deemed more important than the actual vertical movement of the arm. This could be the reason we see people over-rotating on their serve and losing balance and with virtually no pronation in the serving arm, which is created by the recoil of all the energy moving upward.

NamRanger
01-13-2009, 07:35 AM
I didn't say that the kinetic chain is the first thing taught. But when someone asks in a forum how to improve their serving technique the kinetic chain concept is usually one of the ideas presented.

Also, the main idea of the post is that the kinetic chain is flawed in its application. Although the body does move in this complex pattern, it is not a conscious effort by the player and never was even when first learning. To try and consciously coordinate these complex movements can result in poor form and injury.

I wanted to call attention to the fact that the arm starts its movement at the same time as the body and not just in a passive form. The arm must move into position at the same time as the body is rotating. Then, once they are in the hitting position, the elbow can straighten, the forearm can pronate, and the ball struck.



Sometimes players have to consciously recorrect their technique. Even though professional level footwork is subconscious, they had to do thousands upon thousands of hours of training to make their footwork 2nd nature.



Serving for some people is an ackward and unnatural motion. I have seen plenty of players who are just serving without thinking, and their kinetic chain is completely out of sync. If the do not consciously practice it, it can never become subconsciously done.



The arm does not move with the body. The arm is moving as a result of the body creating an upward and forward force.

SystemicAnomaly
01-16-2009, 04:19 AM
Ok. So i was watching some slow motion video of pro serves. And the biggest thing that I noticed was how the so called "kinetic chain" is almost non existent...

I didn't say that the kinetic chain didn't exist. Just that it is a little more simple in execution than what was previously thought..

I do not agree with this. The kinetic chain of the serve is not simple at all. However, it may not be all that important for a player to understand all the details or intricacies of the kinetic chain. On the other hand, it is probably beneficial for a good coach to understand these details.

A novice player does not necessarily need to be aware of the term, kinetic chain, at all. However, as a player develops and refines his/her strokes, it may be important to become aware of some of the details.


... I mainly suggest that the torso and arms start moving at the same time, with the arm actually moving at a faster speed. When the rotation is complete the legs are fully extended, the chest is mostly open to the net, the upper arm is elevated, with the final part of the chain starting to occur. The new kinetic chain should merge trunk rotation and upper arm elevation into one movement, try to rotate your body without moving your arm, its impossible. People, like myself, who don't have access to high quality coaches and fancy facilities are left to discover tennis by themselves, and with the USTA and other people giving out advice that is too technically advanced for anyone to actually incorporate into their game is potentially hazardous. The kinetic chain, while it happens, is a natural development in the service motion and should not be forcibly incorporated.

As a first order approximation, it might very well be useful to think of some of these elements happening at the same time. However, if flaws exist because of this notion, it may become necessary to refine these ideas. For instance, the arm and torso do not really move together (at least not all of the time). At the racket head drops and the torso is rotating (back toward the net), the torso actually leads the elbow & arm -- the elbow/arm lags behind a bit which results in a pectoral stretch. When this pectoral stretch is released, the arm starts to accelerate faster than the torso rotation.

The USTA (& others) is not forcing the concept of the kinetic chain down anyone's throat. It is presented for those who are ready to hear about it. Some players will benefit from knowing about the details while others will not. One must learn how to crawl and then walk before running. It is true that a good coach should not overwhelm the novice player with advice that is too technically advanced. That advice is meant players who already know much of the basics and are probably ready to learn more about the details.