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Tóm tắt nội dung (trích từ tài liệu gốc): Vol. 6, No. 3 / 2004 TM High-Performance TheUSTA NewsletterforTennisCoaches Understanding Optimum Technique Lance Jeffrey In Today's Game by Scott Riewald, Ph.D. and Paul Lubbers, Ph.D., adapted from High Performance Coaching Study Guide Having solid fundamentals of tennis tech- obeyed by all players. One of these commonalities Andy Roddick's forehand is characterized by solid nique is one of the key components that is how the ball is contacted. Even though many fundamentals and elements of style which are enable a player to reach his or her poten- professional players demonstrate different un
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Vol. 6, No. 3 / 2004
TM
High-Performance TheUSTA NewsletterforTennisCoaches
Understanding Optimum Technique Lance Jeffrey
In Today's Game
by Scott Riewald, Ph.D. and Paul Lubbers, Ph.D., adapted from High Performance Coaching Study Guide
Having solid fundamentals of tennis tech- obeyed by all players. One of these commonalities Andy Roddick's forehand is characterized by solid
nique is one of the key components that is how the ball is contacted. Even though many fundamentals and elements of style which are
enable a player to reach his or her poten- professional players demonstrate different unique to him.
tial. When a player masters the fundamentals of techniques during their respective swings--
technique, he or she can consistently produce due to differences in style, age, and physical critical mechanical fundamentals from individual
the most efficient, effective and successful size--the path and orientation of the racquet styles. Focus on instilling these fundamentals of
strokes while minimizing the risk of injury. These at the instant of ball contact are all very similar. technique and eliminating technical flaws that
fundamentals transcend different playing styles can lead to injury or limit performance, while at
and are relevant and applicable to virtually all Fundamentals, Style and Technical Flaws the same time allowing the player to evolve his
ages and levels of play. Coaches often have differing opinions on or her own individual style.
The goals of technique training are threefold: what the fundamentals of a stroke actually are, Optimum Technique
since it is very easy to confuse stylistic aspects The goal for all coaches should be to optimize
1. To understand what the fundamentals of of technique with the essentials. All players
technique are; bring unique aspects of technique to the game the technique of each player with whom they
of tennis that are specific to their body types work. With that said, no standard technique or
2. To be able to recognize and delineate and approach to the game. This is referred to as swing path for a stroke is going to be optimal for
among fundamentals, styles, and techni- style. For example, one player may have a small all players; what is optimal technique for one
cal flaws; and loop in her backswing as she prepares to hit a player may not be optimal for another.
forehand. Another may have a slightly larger
3. To be skilled at teaching technique in the loop. Is this a stylistic difference in technique While the optimal stroke technique may
context of the player's overall development. or does it represent a breakdown in the funda- vary from player to player, all tennis strokes
mentals of the forehand? One way to approach
Fundamentals of Technique this is to look at performance and potential continued on page 4
Fundamentals are those aspects of tech- injury aspects of the stroke. If the player's tech-
nique is likely to result in an injury or limit per-
nique that remain consistent from player to play- formance we would call this a technical flaw
er, regardless of playing style, age or level of play. and it should be corrected. However, in this
These are the mechanical features that must be example, since we see players who are able to
hit either type of shot with consistency, accura-
In This Issue cy and power, and neither shot increases the
injury risk to the player, we would not view this
USA Tennis High Performance as a flaw, but rather a stylistic difference in
technique. Either technique is acceptable and
Coaching Program Update 2 players should be encouraged to find what
works best for them.
Forehand Returns 5
As a coach, you need to be able to distinguish
Optimum Technique and
the Phases of a Stroke 10
DEAR COACH USA Tennis High Performance
Coaching Update
I n this issue of High-Performance Coaching, you will find that we have dedicated a great deal of space to most coaches'
favorite topic: Technique. In the coaching profession there is never a shortage of ideas, opinions and innovative ways
to address technique. Perhaps the information in the following pages will clear the way for you to examine what you
believe to be the "truths" of technique and help you as you teach the fundamentals to your players.
Speaking of the coaching profession, we recently came across an article that belittled the role of coaches in the United
States and the manner in which they coach. Dr. E. Paul Roetert, Managing Director of USA Tennis High Performance, felt
strongly enough about what was written in this editorial by a physical educator that he wrote a response entitled Coaching
as a Profession. Dr. Roetert's article addresses what was written and, at the same time, challenges all of us to strive to learn
and improve ourselves so that we ensure that Coaching stays a Profession.
As always, we hope that you will enjoy this issue of High-Performance Coaching. If you have any suggestions or comments,
please feel free to contact us at Coaching@usta.com or 305-365-USTA.
Paul Lubbers, Ph.D.
Director, Coaching Education
USA Tennis High Performance
USA Tennis High Performance Coaching Program Update
The USA Tennis Coaching Education Department is accepting applications for the USA Tennis High Performance
Coaching Program. Over 400 coaches throughout the United States have participated in this program, which is intended
specifically for the coach who is working with players striving for excellence in competitive tennis (i.e., sectional and
national ranked junior players to collegiate and young professionals. Applications for the 2005 program dates are available
by contacting Bobby Bernstein at 305-365-8711 or e-mailing us at Coaching@USTA.com. We encourage all interested
coaches to apply as soon as possible. See page 12 for dates, locations and application deadlines.
USA Tennis High Performance Coaching Program Attendance
The following list of coaches successfully completed the May 11-16, 2004, USA Tennis High Performance Coaching
Program in Houston, Texas. Congratulations to all of the coaches for their hard work and dedication toward helping improve
the level of play in the United States. Job well done!
Jim Blacketer Christopher DeVore Gerry Perry RJ Tessier
Lubbock, TX Flower Mound, TX Springfield, MO Houston, TX
Tim Blenkiron Greg Haywood Jason Peters Chris Wade
Las Vegas, NV Ojai, CA Wichita Falls, TX Dallas, TX
Carey Brading Doug Kruger Scott Flippin Read Meredith Geiger Walton
Littleton, CO Little Elm, TX Houston, TX Austin, TX
Thomas Brinkhoff Todd Norton Blake Russ John Wilkerson
Ventura, CA Houston, TX Woodland Hills, CA Houston, TX
Steve Bryan Kevin O'Shea Craig Sandvig
Clear Lake Shores, TX Austin, TX University City, MO
Shirish Deshpande Oliver Stephens
Omaha, NE Monterey, CA
2 Vol. 6, No. 3 / 2004 THE USTA NEWSLETTER FOR TENNIS COACHES
USA Tennis High Performance Update
Coaching as a Profession by E. Paul Roetert, Ph.D., Managing Director of USA Tennis High Performance
Irecently read an editorial in a professional journal that really 1. Developing and/or updating your philosophy of coaching. Rick Stewart/Getty Images
disturbed me. The editorial was written by a physical educa- 2. Communicating with and motivating your players.
tion professor with a background in health education. That 3. Conditioning players.
sounds like a pretty good background--in fact, I believe that we 4. Planning for the season, both practices and matches.
often don't promote the health benefits of physical education 5. Teaching specific skills in a proper progression.
enough. But here's what concerned me: All of these skills, and many more, are covered in the USA
Tennis High Performance Coaching program, so if you haven't
This professor stated that he has approached physical educa- taken part in that program yet, look on page 2 for further infor-
tion as a health educator, in contrast to how a coach might. He mation. Over 400 High Performance coaches have already partic-
went on to say that he occasionally lapsed into the coach men- ipated. Oh, and for that physical educator mentioned previously,
tality. Finally, he points out that coaches often deliver physical make sure he never works with your athletes.
education as a bitter pill, forcing athletes to do things not
because it's fun but because it must be done even though it is Need Hi res. from Dave
painful or uncomfortable. All I can say is, "Boy, am I glad this guy
is not a coach." In fact, I wonder about his
skills as a teacher. All good coaches are, in
my opinion, also good teachers. They pos-
sess the ability to teach skills and, at the
same time, motivate the learner to work
hard to reach his or her potential.
Coaches can have a tremendous impact
on players' lives--both positive and nega-
tive. It is our job as coaches to make sure
that our influence is as positive as possible.
Coaching tennis is a step beyond just
teaching the strokes. In fact, it requires a
more comprehensive approach. Coaching
is directly related to competition, it
occurs over an extended period of time
and it encompasses the overall develop-
ment (physical, mental, emotional, tennis
skills and strategy) of an athlete. That's
why a coach's job is so important.
As a coach, you must continually strive
to better yourself. Study successful coach-
es, not just in tennis, but also in other
sports. You will start recognizing specific
traits all good coaches share. Look for
coaches that have strong ethics, a good
coaching philosophy, specific knowledge in
the technique and tactics of the sport and
a desire to continually improve. Many
occupations, such as doctors, lawyers and
teachers have educational and/or practical
requirements necessary to retain profes-
sional status. As a coach, you owe it to
yourself and your students to keep up with
the latest information in the field of coach-
ing as well. Continuing education can be a
key to staying at the top of your profession.
Consider upgrading your knowledge in the
following areas, just to name a few:
THE USTA NEWSLETTER FOR TENNIS COACHES 3 Vol. 6, No. 3 / 2004
continued from page 1
Understanding Optimum Technique continued
should share the following four characteristics and how they influence and drive these move- Loading and Unloading
(Saviano, 1999; Schonborn, 1998): ments. When coaches combine their practical Muscles are like rubber bands, to some
tennis teaching experience with knowledge of
1. It is simple. The optimal technique uses tennis biomechanics, they can accurately ana- extent, in that when they are stretched rapidly
as many segments as necessary to pro- lyze strokes, prescribe training and exercises, they store energy that can later be released. In
duce an effective shot. and maximize skill development while minimiz- preparation for a shot, the muscles of the lower
ing the risk of injury to their players. To help body and trunk are stretched, allowing them to
2. It is efficient. When using the optimal you become better equipped to analyze and subsequently contract more forcefully as the
technique, a player produces the shot with develop optimal technique, we want to describe player unloads and executes the shot. Once
minimum effort relative to the desired several key concepts of biomechanics and illus- loaded, the muscles must be unloaded quickly
results. In addition, use of the optimal trate how these principles are used by some of to make the best use of the elastic energy that
technique minimizes stress to the body today's top players. was stored during loading. Timing and coordi-
and helps to prevent injury. nation are therefore critical for tapping into
Forces and Torques this "free energy."
3. It is effective. Using the optimal tech- A force can be defined simply a push or pull.
nique, the player can successfully execute Momentum
the desired shots. Forces are what drive all movement. Forces Momentum is essentially the quantity of
occur inside (e.g., muscle contractions, joint
4. It is flexible and versatile. The player contact forces) and outside (e.g., ground reaction motion an object possesses and is equal to an
can adapt the technique to the tactical forces, friction, gravity) the body. How well the object's mass multiplied by its velocity. There
requirements of the game situation. body creates and manages these forces deter- are two types of momentum used in tennis
mines, among other things, how well a player strokes and both are important in today's game.
As a coach, you can help players acquire can move, develop power, and maintain stability. � Linear momentum, as the name suggests, is
optimum technique by teaching them the
mechanical fundamentals of stroke production, Typically, when a force is applied to an momentum in a straight line. Linear momen-
while still allowing them to evolve their own object that object will rotate. This tendency for tum is created by the forward step in a square
individual stroke characteristics. A good exam- a force to cause rotation is called a torque or stance forehand.
ple of this is the serve of both Roger Federer and moment of force. Think of a see-saw. When a � Angular momentum is rotational momentum
Andy Roddick. Both players have mastered the person sits on one side of the see-saw, the force and is created by the rotations of the various
fundamentals of technique, yet their technical of his weight creates a torque and causes the body segments. The open stance forehand
styles of hitting the ball are different. see-saw to rotate about its axis. uses significant angular momentum. The
tremendous increase in the use of angular
Technique as Part of a Whole Process One way that torque impacts tennis play can momentum in ground strokes and serves has
It is important to look at technique develop- be seen when looking at muscles and how they had a significant impact on the game of tennis.
function. In all tennis strokes, muscular forces One of the main reasons for the increase in
ment as part of the larger process of developing produce torques that rotate body segments power in the game today is the incorporation
a player's ability to play the game successfully. around body joints. In the service motion, for of angular momentum into ground stroke and
Good technique should not be a goal unto itself, example, the internal rotation of the upper arm, serve techniques.
so keep the isolation of technique work to a that is so important to the power of the serve, is
minimum. When working on technique, try, the result of an internal rotation torque at the There are several additional points to note
when it is appropriate and possible, to incorpo- shoulder joint caused by muscular contractions. about momentum. First, momentum can be
rate the broad spectrum of skills required to play To rotate a segment with more power a player transferred from one object to another. Second,
the game. For example, tactical understanding is would generate greater muscle force. momentum can be changed from one form to
intricately tied to technique. Any discussion of another. This is probably most clearly seen
the fundamentals of technique must include The Kinetic Chain when we consider the angular momentum
the development of tactical patterns that are All the different segments of the body are developed by the coordinated action of the dif-
based around a player's technical strengths. ferent body segments being transferred to the
linked together. What happens in one part of the ball and changed to linear momentum as it
Technique and Biomechanics body impacts what happens everywhere else. leaves the racket after contact.
The terms "technique" and "biomechanics" Power generation in tennis starts from the ground
up, and it is important for players to tap into the Center of Gravity and Balance
are often used interchangeably when discussing strength and the power of the legs and torso to Understanding the concepts of the center of
tennis, but there are slight--yet important-- develop racquet head speed. Recognize it is pos-
differences in what these terms mean. Tech- sible to achieve high racquet head speeds using gravity and balance is enormously important if
nique refers to how a movement is performed only the shoulder and arm, but this places greater you are to coach tennis successfully. These con-
without necessarily giving consideration to the stress on the upper body and can lead to injury. cepts are interrelated and have a profound
physical factors that influence the movement.
Biomechanics goes a little deeper to study and continued on page 9
understand the forces experienced by the body
4 Vol. 6, No. 3 / 2004 THE USTA NEWSLETTER FOR TENNIS COACHES
TECHNIQUE Forehand Returns
Top to bottom: by E. Paul Roetert, Ph.D., Managing Director
Tim Henman, of USA Tennis High Performance
Thomas Johansson, I n these sequence pictures, we will analyze the forehand returns
Serena Williams. of Tim Henman, Thomas Johansson and Serena Williams. More
specifically, we are looking at the forehand return as these players
are being pulled wide off the court by their opponent's serve. Although
there are differences in these players' respective returns, there also are
some clear commonalities.
Keep in mind that each of these players uses a different grip.
Henman is closest to an Eastern Forehand grip, Williams employs a
true semi-Western grip and Johansson is closer to a Western. These
grips likely developed because of the way these players were taught,
as well as the court surfaces on which they grew up playing. Henman
played mostly on faster court surfaces growing up (including grass),
Williams mostly on hard courts and Johansson mostly on clay. These
grips affect not only game style, but also the players' swing path, as
can be seen in these photos of the forehand return. Henman exhibits
a shorter backswing and more of a blocking action whereas Johansson
and Williams have a more extended backswing and follow-through.
The first thing to focus on is how well-prepared all three players
are. They all utilize the split step very well, enabling them to explode
forward and sideways to the ball. It looks like Henman doesn't expect
the wide serve as much as the other two players; therefore he's not
able to transfer as much body weight into the shot.
Each of these players steps out with the right leg first. The photos
clearly show that tremendous leg strength is needed to be able, not
only to generate ground reaction forces, but also to be able to recover
to the middle of the court after contact. Note that although these
players are hitting a difficult return, they focus on staying as bal-
anced as possible while keeping their head still throughout the shot.
One of the things that helps all three players to achieve this balance
is the use of the left arm.
Because of the speed of the serve in the men's game, we see that
Henman and Johansson make contact with the ball earlier than does
Williams. This gives Williams a bit more time to set up and take a
good cut at the ball.
As the players make contact it is clear that each shot has a differ-
ent purpose. Henman has a short backswing and focuses on getting
the ball back to give himself time to recover. He's not able to provide
much force from that position, but with his excellent athletic ability,
he is looking to keep the ball low and get back into position for the
next shot. Williams and Johansson are hitting a much more forceful
shot, although Williams is set up for the quicker recovery.
Williams gets an excellent shoulder turn, followed by a quick and
strong push-off to recover. Johansson also has a very good shoulder
turn, but he looks like he's going more for a winning shot, especially
judging by how far beyond the doubles sideline he ends up. Besides
the obvious technique differences (see comments about the grips
above), the key differences among these shots are how wide the
serves are and how well each player has anticipated the serves. All
three of these players clearly have excellent focus on the ball, superb
timing and great balance while they execute their forehand return.
5 Vol. 6, No. 3 / 2004 THE USTA NEWSLETTER FOR TENNIS COACHES 1
2 3 4
5 6 7
Photos by Lance Jeffrey
8 9 10
8 Vol. 5, No. 4 / 2003
continued from page 4
Understanding Optimum Technique continued
effect on the success or failure of stroke A player uses static balance when he or base of support--the one foot remaining
production. Loss of balance or poor bal- she prepares for a serve. on the ground--or you will fall over. Once
ance is one of the single biggest causes of the COG falls outside the base of support,
errors in tennis. � Dynamic balance is the ability to con- it becomes difficult to maintain balance.
trol the body during motion. A player
Center of Gravity uses dynamic balance when he or she Balance and stability are essential in
The center of gravity (COG) is an changes direction after hitting a shot. all aspects of tennis, from movement to
hitting a shot. The following points relate
imaginary point around which body For the body to stay balanced, the to balance and should be followed by all
weight is evenly distributed. The center center of gravity must be located over the tennis players
of gravity typically lies at the level of the base of support. A good way to picture the
belly button when a player is standing. base of support is to construct an imagi- � Maintain good upper body posture,
However, a player's COG does not stay in nary rectangle between your feet. The with the head up and the shoulders and
one place and can change considerably as feet themselves serve as two sides of the back relatively straight.
body segments are moved. This concept is rectangle. The other two sides are formed
critical to understanding balance and by drawing a line between both sets of � Keep the upper body as still as possi-
stability and how gravity affects tennis toes and another between the heels. As ble, with minimal movement. That is
technique. long as your COG sits over this base of especially important with the head
support you will maintain balance. during all the phases of a stroke.
Balance and Base of Support
Balance is the ability of a player to Try this as an experiment: Place your � Use a proper base of support by keeping
feet shoulder-width apart and you should the feet at approximately shoulder-
control his or her equilibrium or stability. find that it is easy to get your balance. width apart.
As a coach, you need to know and under- Now lift one foot off the ground. When you
stand two types of balance: do this, you will either have to shift your � To enhance stability during the back-
weight so it is centered over your new swing/preparation phase, lower your
� Static balance is the ability to control center of gravity by bending your knees.
the body while in a stationary position.
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THE USTA NEWSLETTER FOR TENNIS COACHES 9 Vol. 6, No. 3 / 2004
FUNDAMENTALS Optimum Technique and the
Phases of a Stroke by Scott Riewald, Ph.D. and Paul Lubbers, Ph.D.
Andre Agassi: Preparation Phase
Amazing! In this picture, we see some of the keys that
characterize aspects of great preparation:
� Loading of the large muscle groups that include the legs,
hips and trunk. Please note the shoulder/hip separation,
which provides Andre with large amounts of stored ener-
gy that then can be used in the hitting phase.
� An established position where the weight is primarily
shifted to the back leg with a low center of gravity and
solid base of support.
� Excellent balance where his head is still and shoulders
level.
� The use of the non-dominant arm which aids in shoulder
rotation and also serves as a counterbalance to the rac-
quet arm.
10 Vol. 6, No. 3 / 2004 Maria Sharapova: Hitting Phase
Here we see Maria Sharapova hitting her signature
square stance backhand. She is initiating the hitting phase
of the stroke by beginning to uncoil her trunk and shoulders
and by transferring her weight forward. This illustrates the
combination of angular and linear momentum that is seen
in almost every stroke used in today's game. A few other
things to note:
� Her racquet head is well below the ball, which means her
swing path will travel from low to high and will aid her in
the development of topspin.
� Many players use the wrist (ulnar deviation) to further
drop the racquet head below the ball.
� Sharapova displays excellent balance with a wide base of
support, her head up, shoulders level and eyes focused
on the ball.
THE USTA NEWSLETTER FOR TENNIS COACHES
Ask the Expert continued
Justine Henin-Hardenne: Contact Phase
Here we see Justine Henin-Hardenne hitting with classic
form, a running backhand. At contact point, she is displaying
tremendous balance and strength. Her head is down and her
eyes are focused on the ball. At this point she has a low center
of gravity with a solid base of support. This base provides her
stability as the large muscles uncoil and transfer energy through
the kinetic chain to the racquet. When examining the contact
point look for the following characteristics.
� Full extension of racquet arm at contact. Note that the type of
grip will impact the location of the contact point. In this case,
Henin-Hardenne uses a full Eastern backhand grip which
brings her contact point farther out into the court.
� Racquet angle at contact is square ( �5o).
� Still head and level shoulders.
� Continuation of swing path through the contact point.
photos by Lance Jeffrey
Roger Federer: Follow-Through 11 Vol. 6, No. 3 / 2004
Reigning US Open champion Roger Federer is executing a
beautiful follow-through that displays the tremendous angular
momentum and racquet head speed that is part of the modern
forehand. The follow-through serves as a means to decelerate the
racquet after contact and contributes to making the racquet fol-
low the planned path of the ball for as long as possible. Without a
follow-though, a player would experience much greater loads on
the shoulder, potentially leading to injury. Some other guiding
principles that relate to the follow-through are:
� Depending on the type of shot executed, the ground reaction
force can drive a player off the ground.
� The best players exhibit great dynamic balance and body con-
trol--even when off the ground.
� Head and eyes remain on contact point after the ball is off the
strings.
THE USTA NEWSLETTER FOR TENNIS COACHES
UNITED STATES TENNIS ASSOCIATION Presorted
Standard
USA Tennis High Performance US Postage
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High-Performance USA Tennis High Performance
Coaching Program Dates
Published Quarterly By
Program Dates for 2004 and 2005
USA Tennis Coaching
Education Department Date Location Application Deadline
7310 Crandon Boulevard Program is Full
Key Biscayne, Florida 33149 November 16-21, 2004 Atlanta, Georgia November 15, 2004
February 15, 2005
305-365-8782 January 11-16, 2005 Key Biscayne, Florida
Editor May 17-22, 2005 Carson, California
Paul Lubbers, Ph.D.
Applications for the above program dates are available
Editorial Consultant by contacting 305-365-USTA or e-mailing us at
Mark Preston
Coaching@USTA.com. We encourage all interested
USTA Staff coaches to apply as soon as possible.
Bobby Bernstein
Scott Riewald, Ph.D.
� 2004 United States Tennis Association
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