See discussions, stats, and author profiles for this publication at: https://www.researchgate.

net/publication/274370956

Biomechanics of Advanced Tennis

Book · January 2003

CITATIONS READS
29 14,485

3 authors:

Bruce C Elliott Machar Reid

University of Western Australia Tennis Australia
341 PUBLICATIONS 12,293 CITATIONS 230 PUBLICATIONS 5,771 CITATIONS

SEE PROFILE SEE PROFILE

Miguel Crespo
International Tennis Federation
293 PUBLICATIONS 1,909 CITATIONS

SEE PROFILE

All content following this page was uploaded by Bruce C Elliott on 23 April 2015.

The user has requested enhancement of the downloaded file.

 Downloaded from bjsm.bmjjournals.com on 23 April 2006

Biomechanics and tennis

B Elliott

Br. J. Sports Med. 2006;40;392-396

doi:10.1136/bjsm.2005.023150

Updated information and services can be found at:

http://bjsm.bmjjournals.com/cgi/content/full/40/5/392

These include:
References This article cites 19 articles, 1 of which can be accessed free at:
http://bjsm.bmjjournals.com/cgi/content/full/40/5/392#BIBL

Rapid responses You can respond to this article at:

http://bjsm.bmjjournals.com/cgi/eletter-submit/40/5/392

Email alerting Receive free email alerts when new articles cite this article - sign up in the box at the
service top right corner of the article

Topic collections Articles on similar topics can be found in the following collections

Sports Medicine (1225 articles)

Notes

To order reprints of this article go to:

http://www.bmjjournals.com/cgi/reprintform
To subscribe to British Journal of Sports Medicine go to:
http://www.bmjjournals.com/subscriptions/
 Downloaded from bjsm.bmjjournals.com on 23 April 2006
392

REVIEW

Biomechanics and tennis

B Elliott
...............................................................................................................................

Br J Sports Med 2006;40:392–396. doi: 10.1136/bjsm.2005.023150

Success in tennis requires a mix of player talent, good concentric phase (shorten) is enhanced. This is
also supported by the fact that the concentric
coaching, appropriate equipment, and an understanding action begins with the appropriate muscles
of those aspects of sport science pertinent to the game. This under higher tension than would be created if
paper outlines the role that biomechanics plays in player they were to contract purely concentrically from
a resting state. Research has shown that the
development from sport science and sport medicine benefit to performance from these two factors,
perspectives. Biomechanics is a key area in player particularly the muscle pre-tension, is critical to
development because all strokes have a fundamental success in sports such as tennis.6 Examples from
selected strokes are:
mechanical structure and sports injuries primarily have a
mechanical cause. N Service: A subtle coaching point in maximis-
ing power in the serve is the timing of the ‘‘leg
...........................................................................
drive’’ with the racquet preparation for the
drive to the ball. The eccentric stretch and pre-

S
uccess in tennis is greatly affected by the tensing of the anterior shoulder muscles
technique a player uses and biomechanics (particularly the internal rotators) is max-
plays an integral role in stroke production. imised by a vigorous leg drive which positions
All strokes have a fundamental mechanical the racquet ‘‘down behind and away from the
structure, and sports injuries primarily have a lower back’’ in preparation for the drive to the
mechanical cause.1 Player development based on ball.
scientific evidence allows an individualised
approach to be structured, with due considera- N Groundstrokes: Rotation of the shoulders
greater than the hips (creating a separation
tion to the key mechanical features of each skill, angle) and the positioning of the upper limb
while also fostering flair and permitting the relative to the trunk during the backswing
physical characteristics of a player to be con-
phase of these strokes, place appropriate
sidered. An understanding of biomechanics from
muscles on stretch. This is why in the back-
a sports medicine perspective is also important if
hand a separation angle (one handed ,30˚;
player development is to occur with minimal risk
two handed ,20˚) is created in the backswing
of injury.
in preparation for the swing to the ball.7
The examples given in the following sections
are intended to reflect general directions rather N Volley/service return: The split step, an inte-
gral part of preparation for a volley, service
than provide a comprehensive review of the
literature. More detailed reviews can be found in return, or groundstroke, places the quadriceps
the ITF publication Biomechanics of advanced muscle (extensor at the knee joint) on stretch,
tennis,2 and the books From breakpoint to advan- permitting storage and subsequent release of
tage,3 The physics and technology of tennis4 and energy to enhance quick movement in pre-
Biomechanical principles of tennis technique: using paration for the subsequent stroke.
science to improve your strokes.5
The key to the recovery of the elastic energy is
The review will be presented under a number
the timing between the stretch and shorten
of headings that reflect the different areas in
phases of the motion. The benefit of this stored
which biomechanics is important to player
energy is reduced if a delay occurs between these
development. Firstly, biomechanics from a gen-
phases of the movement. In the bench press,
eral perspective will be followed by the role it
plays in stroke production. Sports medicine, as it after a period of about one second, 55% of the
plays a role in the development of stroke stored energy was lost.8 Elliott et al9 showed that
production, is then discussed from a biomecha- speed of internal rotation of the upper arm was
nical perspective. increased by about 20% for a no-pause compared
with a 1.5 second pause condition. In tennis it is
therefore essential that only a short pause occurs
GENERAL THEORY OF BIOMECHANICS
between the backswing and forwardswing
Biomechanics theory provides coaches, players,
....................... phases of stroke production or at maximum
and sport science support staff with a general
knee flexion during the serve.
Correspondence to: framework for the development of stroke pro-
Professor Elliott, University duction. I will discuss a number of the general
of Western Australia, principles that guide this development. Kinetic chain
Perth, WA, Australia; There are generally two segment coordination
bruce.elliott@uwa.edu.au
Muscle pre-tension (elastic energy) strategies used in tennis (table 1). In strokes
Accepted In a stretch-shorten cycle, elastic energy stored where power is required (such as the service and
10 December 2005 during the eccentric phase of the action (the groundstrokes), a number of body segments
....................... stretch) is partially recovered, such that the must be coordinated in such a way that a high

www.bjsportmed.com
 Downloaded from bjsm.bmjjournals.com on 23 April 2006
Biomechanics and tennis 393

Table 1 Coordination strategies in tennis

Power stroke (the service)10 Precision stroke (the volley at net)11

Leg drive and trunk rotations) shoulder speed Shoulder rotation, forward step of ) racquet speed
(forward/shoulder-over- the front leg, and forward
shoulder/twist) movement of the racquet arm all
work together as a unit
+
Upper arm elevation and ) elbow speed
flexion
+
Forearm extension and ) wrist speed and
pronation and upper arm racquet orientation
internal rotation
+
Hand flexion ) racquet speed

racquet speed is generated at impact. Where precision is The complexity of fig 1 is one reason why coaches often
needed, the number of segments is reduced and segments prefer to use the ‘‘critical points’’ approach as the basis for
operate more as a unit (such as the volley at the net), although their analyses.
the drive volley now challenges this general principle. Irrespective of what procedure is used, the four stage
Efficient function, with maximal performance and mini- approach to technique development (preparation, observa-
mal risk of injury, requires optimum activation of all the links tion, intervention, and reassessment) developed by bio-
in the kinetic chain designed for power.12 Injury is often mechanists in combination with pedagogists has had a major
associated with alterations in the flow of energy across influence on the way tennis stroke production is analysed,
segments, such that if one segment is removed from the interventions developed, and performance reassessed.
chain, then there is an increased reliance on the others to
accommodate this loss, which may lead to tissue overload. Equipment design
A discussion of this topic is beyond the scope of this paper,
Variability in stroke production and the reader is directed to the book by Brody et al4 for a
Work by Knudson13 has shown that selected aspects of the complete review of this broad topic. However, there is no
stroke production of high performance players are variable, doubt that modern racquets have enabled the ball to be hit
whereas other aspects are repeatable. For instance, in the with a higher speed than was possible with previous designs.
forehand drive, wrist and elbow angular positions are Lighter racquets with larger ‘‘areas of percussion’’ and new
generally consistent at impact. However, this repeatable string designs have all affected modern technique and are the
angular position was not the result of highly consistent primary reason for a number of changes to stroke production
patterns of angular velocity and acceleration of the same discussed below.
joints. That is, a given end result is achieved through a variety
of movement strategies. Coaches in developing stroke BIOMECHANICS OF STROKE PRODUCTION
production must then vary drills—for example, pace, spin, Serve/groundstrokes
direction, and height of ball feed or drill structure—to Internal rotation of the upper arm at the shoulder
develop a variety of neuromotor timings associated with a Work by my team has primarily been responsible for
given stroke, to achieve the almost infinite combinations of identifying the important role that internal rotation of the
racquet speed, trajectory, and impact characteristics asso- upper arm at the shoulder joint plays in the service (fig 2)
ciated with a successful return. and the forehand strokes (table 2).10 14 This factor has in
many ways modified the way that these strokes are
Analysis protocols developed at beginner and advanced levels of play. The
Technique analysis falls on a continuum between subjective images in fig 2 show how internal rotation at the shoulder,
(qualitative) and more objective (quantitative) analyses. which begins before impact, continues into the early follow
Research shows that an expansive view of subjective through phase of the service action. Functionally, the internal
technique analysis, the procedure generally used by coaches, rotator musculature must accelerate the upper arm in the
is required if performance is to be optimised. Any effective swing to impact, before the external rotators eccentrically
process must evaluate movement to identify both strengths contract to decelerate this rotation during the follow through
and weaknesses in performance and then diagnose the phase of the action. As the external rotators are much smaller
movement to prescribe an appropriate intervention.15 than their internal rotator counterparts, it is essential that
A variety of models of technique analysis have been specific training is structured to protect the shoulder from
proposed. However, they may generally be divided into injury, as discussed in the sports medicine section below.
approaches that focus on: Remember, these figures relate to the approximate
contributions at impact and take no consideration of such
N analysing general biomechanical principles—for example,
assessment of balance during stroke production, followed
movements as leg drive in the service action. They are
indicators of the movements responsible for the generation of
by the application of force and inertia in the development
racquet speed and do not indicate the importance of a
of racquet speed and so on
particular movement in a stroke. For instance, in the power
N identifying variables that are structured in a deterministic
model—the mechanical method (see fig 1 for a model of
serve, pronation is primarily responsible for racquet orientation,
and elbow extension assists in the generation of impact height.
the serve). The advantage of this approach is that the
relations between variables is highlighted Trunk rotations in the serve
N key technique points (position of the racquet at the
completion of the backswing or impact) being identified
The view most commonly held by coaches was that a player
rotated the trunk horizontally about a near vertical axis

www.bjsportmed.com
 Downloaded from bjsm.bmjjournals.com on 23 April 2006
394 Elliott

POWER SERVE

BALL SPEED BALL TRAJECTORY

Ball speed at impact (horizontal ~ 0) Air resistance/gravity

PREPARATION/BACKSWING Vertical
movement of
• Grip
ball
• Foot positions

Ball spin
• Trunk rotation
– hips Racquet trajectory and
– shoulders alignment
• Racquet rotation Off-centre
– displacement impact
Vertical and horizontal
• Type of swing racquet speed
– full
– abbreviated
• Body orientation

Angle of racquet face

• Ball toss Grip
– relationship of arms
Racquet speed (horizontal)

– position of non-racquet arm

Upper limb
angles
FORWARDSWING
• Leg drive
Trunk alignment
• Position at maximum external rotation
(off the ground)
• Shoulder and arm alignment
• Trunk rotations
– twist
– forward Pre-impact ball path and height
– shoulder-over-shoulder
• Weight transfer
• Non-racquet arm tuck for trunk rotation
• Shoulder flexion
• Elbow extension
• Shoulder internal rotation
• Wrist flexion

FOLLOW THROUGH
• Internal rotation
• Landing
– foot
– position on court IMPACT POSITION
• Racquet path
• Off ground and in court
• Shoulder abduction angle
• Body extended
Racquet (strings, impact position) • Racquet not aligned with forearm

Figure 1 Model of the power serve in tennis. Published with permission of the International Tennis Federation.

during the forward swing in the service action. Players knew Lower limb and pelvic drive in groundstrokes
better and have tilted the trunk to rotate more in a shoulder- Research at the University of Tokyo has provided insight into
over-shoulder orientation, rather than a simple horizontal the role of lower limb drive and pelvic rotation in the
rotation of the shoulders. They obviously positioned them- forehand17 and backhand18 strokes. The importance of
selves in this manner to enable internal rotation of the upper internal extensor moments at the back hip was identified
arm at the shoulder to play the important role in the service in both the above studies. Again the importance of hip
action that we now know it does (fig 2). Research by (pelvic) rotation has been highlighted in both forehand and
Bahamonde16 on angular momentum in the trunk during the backhand strokes.
serve clearly showed the importance of shoulder-over-
shoulder and forward rotation movements during the service SPORTS MEDICINE
action. Although science again cannot claim that it was the Loading
reason for these movements, it certainly played an integral Epidemiological data have shown that tennis injuries are
role in their integration into player development. Current primarily caused by overuse.3 Loading (the rate of force
research by Elliott, Sweeney, Alderson, and Reid is aimed at development, peak force, and torque are mechanical factors
quantifying the role of the ‘‘back leg drive’’ in the generation of that collectively are often referred to as ‘‘load’’) may be
shoulder-over-shoulder trunk rotation in the service action. applied to the body externally (ground reaction force,

www.bjsportmed.com
 Downloaded from bjsm.bmjjournals.com on 23 April 2006
Biomechanics and tennis 395

Figure 2 Pictures of service action showing shoulder-over-shoulder trunk rotation and internal rotation of upper arm at the shoulder joint. Published
with permission of the International Tennis Federation. The player has given permission for publication of this figure.

vibration) or internally (muscle forces and torques). Research Tennis elbow

on elite players at the Sydney Olympics provided an insight The prevalence of lateral humeral epicondylitis is acknowl-
into the load placed on the shoulder and the elbow joint of edged as a condition that primarily occurs in the recreational
these players.19 These data provided information on leg drive, athlete. Research on the one handed backhand stroke shows
the abbreviated backswing, and service speed as they affected that this condition may be related to the use of faulty stroke
shoulder and elbow loading. In very general terms, this paper mechanics by novice players.21 Skilled players impact the ball
showed the following. with a hyper-extended wrist and extend the hand through
impact. That is the extensor muscles about the wrist joint act
N Loading increased with an increase in service speed. That
is, irrespective of sex, if a player wishes to develop a more
concentrically to develop racquet speed through impact.
However, novice players often strike the ball with the wrist
powerful serve they need to modify technique (rotate flexed (,13˚), while moving the hand at the wrist joint into
selected segments more quickly) and prepare the body further flexion. That is the extensor muscles about the wrist
physically to perform the higher speed movement(s). joint contract eccentrically, before the contraction concen-
N Those players with more effective knee flexion-extension
during the service action were associated with lower
trically following impact. Wrist extensor electromyography
for both groups showed similar levels of activity in the period
loading at the shoulder and elbow. This finding needs to before ball impact, whereas the skilled players showed
be further clarified such that the effect of leg drive on greater electromyographic levels after contact.
loading is assessed; this is currently taking place at the The above study was followed by another with a similar
University of Western Australia. design but with professionals and intermediate level players
N There was a trend for players with very abbreviated
backswings to record higher force levels at the shoulder.
Table 2 Approximate contributions to impact racquet
This finding is also currently being tested in a more
velocity (%)
controlled design.
Topspin forehand
Staying on the topic of loading and the tennis serve, Chow Power serve (forward direction)
et al20 investigated activation on the lower trunk muscles
Shoulder 10 15
during various types of service actions. They showed that co- Upper arm
activation of lower trunk muscles assists in the stabilisation Horizontal flexion 15 25
of the lumbar spine during extension/flexion and rotation of Internal rotation 40 40
this region during the service action. The abdominal muscles Forearm
Extension Negligible Negligible
were more active in the topspin serve than the flat and slice Pronation 5 Negligible
serves during the upward swing of the racquet to impact. Hand
These results reinforced the importance of abdominal and Flexion (palm/ulnar) 30 –
low back exercises (core stability) together with the muscles Flexion (palmar/radial) – 20
about the shoulder and lower limbs in strength and
rehabilitation programmes in tennis.

www.bjsportmed.com
 Downloaded from bjsm.bmjjournals.com on 23 April 2006
396 Elliott

with and without a history of tennis elbow.22 Hand angular

velocity at the wrist, measured by an electrogoniometer, was What is already known on this topic
significantly different in the professionals (4 rad/s, exten-
sion) and intermediate group who had a history of tennis
elbow (0.4 rad/s, flexion). As with the study by Blackwell and
N The biomechanics of tennis has been well researched, but
publications are spread over a wide range of journals
Cole,21 lateral epicondylitis has been associated with an
eccentric contraction of the wrist extensors at impact. No N Furthermore, interpretations of findings are in various
formats, thus limiting their application
significant differences were found in impact acceleration or
elbow kinematics between the three groups.

Muscle balance What this study adds

One of the possible causes of shoulder injury may be peak
strength/torque imbalances in those muscles responsible for
acceleration and then deceleration of the upper arm at the
N This review succinctly integrates biomechanical research
from performance and sports medicine perspectives
shoulder joint. Certainly work by Tod Ellenbecker and Paul
Roetert has provided players, coaches, and sports medicine
personnel with isokinetic profiles of highly skilled and junior has certainly assisted tennis development, it is also important
tennis players.23 The comparison of the concentric strength of to realise that much is still to be accomplished.
one muscle group compared with the eccentric strength of
the antagonist group in throwers was explored by Noffal.24 He Competing interests: none declared
concluded that rehabilitation and injury prevention regimens The player in figure 2 has given permission for its publication.
that include exercises for eccentric external rotation strength
may bring more balance to the dominant shoulder of
throwing athletes. Such information is critical to the REFERENCES
preparation of athletes where explosive concentric and 1 Whiting W, Zernicke R. Biomechanics of musculoskeletal injury. Champaign,
IL: Human Kinetics, 1998.
eccentric contractions are common place. Remember, in most 2 Elliott B, Reid M, Crespo M, eds. Biomechanics of advanced tennis. London:
tennis strokes, the stretch-shorten cycle is characterised by International Tennis Federation, 2003.
eccentric followed by concentric contractions. For example in 3 Pluim B, Safran M. From breakpoint to advantage. Solana Beach, CA:
Racquet Tech Publishing, 2004.
the serve you have: 4 Brody H, Cross R, Lindsay C. The physics and technology of tennis. Solana
Beach, CA: Racquet Tech Publishing, 2002.
N external upper arm rotation at the shoulder during the
backswing slowed by eccentric contraction of the internal
5 Knudson D. Biomechanical principles of tennis technique: using science to
improve your strokes. Solana Beach, CA: Racquet Tech Publishing, 2006.
6 Walshe A, Wison G, Ettema G. Stretch-shorten cycle compared with isometric
rotators at the shoulder preload: contributions to enhanced muscular performance. J Appl Physiol
N concentric contraction of the shoulder internal rotators, in
the drive to the ball, is then slowed by an eccentric
1998;89:97–106.
7 Reid M, Elliott B. The one- and two-handed backhands in tennis. Sports
Biomech 2002;1:47–68.
contraction of the shoulder external rotators during the 8 Wilson GJ, Elliott B, Wood G. The effect on performance of imposing a delay
follow through during a stretch-shorten cycle movement. Med Sci Sports Exerc
1991;23:364–70.
It is therefore apparent that we must train muscles in 9 Elliott B, Baxter K, Besier T. Internal rotation of the upper arm segment during
a stretch-shorten cycle movement. J Appl Biomech 1999;15:381–95.
concentric and eccentric modes, while also recognising that 10 Elliott BC, Marshall RN, Noffal G. Contributions of upper limb segment
large muscle imbalances will lead to injury. This is particularly rotations during the power serve in tennis. J Appl Biomech 1995;11:433–42.
true in the eccentric contraction during the follow through, as 11 Elliott BC, Overheu P, Marsh P. The service line and net volleys in tennis: a
cinematographic analysis. J Sci Med Sport 1988;20:10–18.
the external rotators at the shoulder are required to ‘‘decelerate’’ 12 Kibler B. Kinetic Chain contributions to elbow function and dysfunction in
the rapidly internally rotating upper arm. Prehabiliation or sports. Clin Sports Med 2004;23:545–52.
exercises to minimise loading stresses should be included in any 13 Knudson D. Intra-subject variability of upper extremity angular kinematics in
the tennis forehand drive. International Journal of Sport Biomechanics
training programme before a return to full training.25 1990;6:415–21.
14 Elliott B, Takahashi K, Noffal G. The influence of grip position on upper limb
contributions to racket head velocity in a tennis forehand. J Appl Biomech
CONCLUSIONS 1997;13:182–96.
There is no question that players striving for more power, more 15 Knudson D, Morrison. Qualitative analysis of human movement, 2nd ed.
control, or more variety in stroke production through trial and Champaign, IL: Human Kinetics, 2002.
16 Bahamonde R. Changes in angular momentum during the tennis serve.
error are the primary determinants in changes to stroke J Sports Sci 2002;18:579–92.
mechanics. However, I have shown that biomechanics certainly 17 Iino Y, Kojima T. Torque acting on the pelvis about its superior-inferior axis
plays a role in the process of change. General theory provides a through the hip joints during a tennis forehand stroke. Journal of Human
Movement Studies 2001;40:269–90.
base on which modifications can be made, and an under- 18 Akutagawa S, Kojima T. Trunk rotation torques through the hip joints during
standing of individual stroke mechanics inevitably leads to the one- and two-handed backhand tennis strokes. J Sports Sci
improved performance. Science also enables players to modify 2005;23:781–93.
19 Elliott B, Fleisig G, Nicholls R, et al. Technique effects on upper limb loading in
their training regimens with minimal risk of injury. I have no the tennis serve. J Sci Med Sport 2003;6:76–87.
doubt that the other sports science disciplines (psychology, 20 Chow J, Shim J-h, Lim Y-t. Lower trunk muscle activity during the tennis serve.
exercise physiology, and pedagogy/motor learning) could also J Sci Med Sport 2003;6:512–18.
21 Blackwell J, Cole K. Wrist kinematics differ in expert and novice tennis players
make a case for their role in player development. performing the backhand stroke: Implications for tennis elbow. J Biomech
Areas where science can play an improved role are in the 1994;27:509–16.
linking of growth and development of the body, pedagogy, 22 Knudson D, Blackwell J. Upper extremity angular kinematics of the one-
and skill development. When should selected biomechanical handed backhand drive in tennis players with and without tennis elbow.
Int J Sports Med 1997;18:79–82.
principles be introduced? When should we teach the leg drive 23 Ellenbecker T, Roetert P. An isokinetic profile of the trunk rotation strength in
in the service action from skill development and lower limb elite tennis players. Med Sci Sport Exerc 2004;36:1959–63.
strength perspectives? From a tissue loading perspective, 24 Noffal G. Isokinetic eccentric-to-concentric strength ratios of the shoulder rotator
muscles in throwers and non-throwers. Am J Sports Med 2003;31:537–41.
should we stress the importance of energy storage and 25 Kibler B. Rehabilitation of rotator cuff tendinopathy. Clin Sports Med
muscle pre-tension at an early age? Although sport science 2003;22:837–47.

www.bjsportmed.com
View publication stats