Efficient Deceleration the Forgotten Factor in.5

Efficient Deceleration:The Forgotten Factor inTennis-Specific TrainingMark S. Kovacs, PhD, CSCS,1 E. Paul Roetert, PhD,1 and Todd S. Ellenbecker, DPT, CSCS21Player Development, United States Tennis Association, Boca Raton, Florida; and 2Physiotherapy Associates,Scottsdale, Arizona

Strength and Conditioning Journal Classics are previously published articles that have impacted the strength andconditioning profession. We are pleased to offer current SCJ readers this meaningful classic. REPRINT: Strength andConditioning Journal, December 2008-Volume 30-Issue 6-pp 5869.

S U M M A R Y

EFFICIENT DECELERATION IS PAR-

AMOUNT TO ALLOW FOR FAST

AND EXPLOSIVE CHANGES OF

DIRECTION. BECAUSE MOST TEN-

NIS POINTS HAVE BETWEEN 3 AND

7 CHANGES OF DIRECTIONS, THE

DEVELOPMENT OF THE COMPO-

NENTS IN CHANGE OF DIRECTION

MOVEMENTS IS A MAJOR COM-

PONENT OF COMPETITIVE PLAY.

TRAINING FOR TENNIS REQUIRES

A STRONG UNDERSTANDING NOT

ONLY OF THE ACCELERATION

ASPECTS OF MOVEMENT BUT

ALSO THE NEED FOR TENNIS-

SPECIFIC DECELERATION. IN THIS

ARTICLE, WE REVIEW TENNIS

MOVEMENTS FROM BOTH AN

UPPER- AND LOWER-BODY PER-

SPECTIVE AND DESCRIBE THE

IMPORTANT COMPONENTS OF

TENNIS-SPECIFIC DECELERATION

WITH PRACTICAL EXAMPLES OF

DECELERATION TRAINING IDEAS.

INTRODUCTION

For competitive tennis players,exceptional movement isa requirement to achieve success

in junior tournaments as well as at thecollegiate or professional level. Accelera-tion focused training is common instrength and conditioning programs for

tennis players; however, less emphasis issometimes given to the importance thateffective deceleration training plays inboth upper- and lower-body movementsof the tennis athlete. The lower bodyneeds to perform large decelerations toprepare for and recover after ground-strokes and volleys, as well as duringthe follow-through and landing phaseof the serve (29). The upper body, par-ticularly the muscles of the upper backand posterior aspects of the shoulder, fea-ture the major muscles that help deceler-ate the upper limbs after ball contact inserves, groundstrokes, and volleys (30).As such, deceleration needs to be consid-ered a vital component of a competitivetennis players training routine to achievepeak tennis performance. To explorethe complex nature of deceleration,a deterministic model has been used toshowcase the multifaceted nature ofdeceleration and the many componentsthat need to be trained to successfullyexecute the correct movements. A deter-ministic model is a systematic model thatis used to analyze and evaluate an impor-tant component of a skill, which providesan approach that is based on a hierarchyof factors that are dependent on the resultor outcome of the performance (22). Fig-ure 1 describes a deterministic model fordeceleration that can help the strengthand conditioning specialist highlightareas that need to be trained during thephases of a periodized training program.

At the simplest level of analysis, deceler-ation is the fine interplay betweenmusculoskeletal, neural, and technicalcomponents. To develop effective decel-eration capabilities in tennis athletes, it isimportant that the strength and condi-tioning program includes ample timeon all 3 of these broad areas of training.

PLYOMETRIC MOVEMENTS

Plyometric exercises typically areincorporated into an athletes programby the strength and conditioning spe-cialist to improve explosive movementsby improving power outputs (21). Plyo-metric movements involve an eccentricloading immediately followed by a con-centric contraction (14). Plyometrictraining enhances athletic performance,typically by improving power outputsas measured by concentric contrac-tions. However, the benefit of plyomet-ric training also aids in the training ofadaptations in the sensorimotor systemthat enhances the athletes ability tobrake, sometimes referred to as therestrain mechanism (35,36). In addi-tion, plyometric training aids in thecorrection of mechanically disadvanta-geous jumping and change of direction-movements. Another added benefitwith respect to deceleration training is

KEY WORDS :

acceleration; deceleration; movement;quickness; speed; tennis

VOLUME 37 | NUMBER 2 | APRIL 2015 Copyright National Strength and Conditioning Association92

the landing components after a plyo-metric type movement. Because plyo-metric movements produce greaterpower outputs, as the result of thegreater use of stored potential energy,than nonplyometric movements (33),

these greater forces require greaterdeceleration abilities. Therefore, train-ing with the use of plyometric move-ments not only improves power andexplosive movements but also resultsin training adaptations during the

landing or deceleration phase of thesemovements. The need to develop thisimproved ability to brake andimprove the restrain mechanism willbe the major focus of the remainderof this article.

Figure 1. Deterministic model of deceleration.

Figure 2. Lower body deceleration after a tennis stroke.

Strength and Conditioning Journal | www.nsca-scj.com 93

LOWER-BODY DECELERATION

Although training acceleration is vitalto help an athlete become faster, thisimproved acceleration ability maynot transfer into improved tennisperformance if the athlete does nothave the ability to decelerate thefaster velocities in the appropriatetime frame and under the neededcontrol to make optimum contactwith the tennis ball. The ability to

effectively decelerate is also impor-tant while transitioning into a recov-ery movement that will allow theathlete to be in position for the nextstroke in the rally. Figure 2 demon-strates the body position and impor-tance of appropriate strength,balance, and coordination, first toaccelerate into the forehand, andsecond to decelerate rapidly aftercontact with the ball has been made.

An athletes ability to decelerate isa trainable biomotor skill and, as such,needs to be included in a well-rounded, tennis-specific training pro-gram. An athlete who can deceleratefaster and in a shorter distance is anathlete who will not only be faster butwill also have great body control dur-ing the tennis stroke. This greatercontrol during the stroke will resultin a greater level of dynamic balance(Figures 1 and 4), which translatesinto greater power of the strokes,and more solid racket and ball con-tact, which results in more effectiveexecution. A major influence on a ten-nis players ability to decelerate ismomentum. Momentum is the prod-uct of the mass of a moving athleteand his/her velocity. As an athletesvelocity increases, momentum isamplified, requiring greater forces todecelerate the fast moving tennisplayer. A larger tennis player (i.e.,greater mass) has a more difficult time

Figure 3. Upper and lower body deceleration after a tennis serve.

Figure 4. Four major deceleration components.

SCJ Classic Article Reprint

VOLUME 37 | NUMBER 2 | APRIL 201594

de-celerating and, if the coach focusesthe majority of movement training onacceleration without focusing ampletime on deceleration, it will result inan athlete who has a faster initialvelocity but who may not be able tocontrol the body to slow down fastenough before and/or after makingcontact with the ball. This will resultin reduced oncourt performance andmay result in the increased likelihoodof injury. It has been proposed in theliterature that the causes of the major-ity of athletic injuries are the result ofinappropriate deceleration abilitiesof athletes and an overemphasis ofacceleration-focused (concentric spe-cific movement) exercises both onand off-court (11,26).

UPPER-BODY DECELERATION

In the upper extremity, the body useseccentric contractions after ballimpact in virtually all strokes to decel-erate the upper-extremity kineticchain. These contractions are of vitalimportance around the shoulder andscapular area because they help tomaintain the critically important sta-bility that is needed to both preventinjury and enhance performance. For

example, during the serve (Figure 3),the upper arm is elevated approxi-mately 90100 degrees relative tothe body (abduction). In this position,large forces are generated by the inter-nal rotator muscles such as the latissi-mus dorsi and pectoralis major toaccelerate the arm and racquet headforward toward an explosive ballimpact.

Immediately after ball impact, themuscles in the back of the shoulder,

including the scapular stabilizers (in-fraspinatus, teres minor, serratus ante-rior, trapezius and rhomboids [27]),have to work eccentrically to decelerate

the arm as it continues to internallyrotate. Fleisig et al. (9) reported

anterior translational forces during the

acceleration and follow-through phasesof the overhead throwing motion to

approximately 13 body weight in the

glenohumeral joint. The posterior rota-tor cuff muscletendon units are

Figure 5. Deceleration and requirement of eccentric strength during a forehand stroke.

Figure 6. Lengthtension curve before and after eccentric exercise. Adapted fromBrughelli and Cronin (3).


responsible for maintaining jointstability by resisting this anteriortranslation/distractional force to pre-vent injury to the glenoid labrum andother structures in the shoulder (9).This deceleration is critical for injuryprevention because the inability todissipate these large forces by themuscles in the back of the shoulderand scapular area can lead to injury(Figure 3). Similar results are seen intennis movements and require appro-priate training (7).

In addition to the high levels of activ-ity identified during the serve, thesame rotator cuff and scapularmuscles work to decelerate the armon the forehand during the follow-through phase. Training these impor-tant muscles provides importantmuscle balance to the tennis player.Players are deficient in these impor-tant decelerator muscles (5,16,31)and do not understand the importanceof training these muscles by incorpo-rating deceleration type trainingprograms into their normal trainingregimens.

TRAINING SPECIFICITY

It has been shown in the scientificliterature that linear accelerationand linear maximum velocity are sep-arate qualities from multidirectionalmovements that require a change ofdirection and/or a deceleration ofmovement (43). Young et al. (43) foundthat straight-ahead sprinting, such asa 100-m sprint in track and field, doesnot transfer directly to the movementstypically seen on a tennis court. Thisresult is caused by the differences inmovement mechanics, muscle firingpatterns, and motor learning skillsrequired to perform straight line sprint-ing versus tennis play that require startand stop movements and numerouschanges of direction in every point.As a result, training for tennis-specificacceleration, deceleration, and recov-ery movements (change of direction)requires movement patterns, distances,and energy system focus that resemblescompetitive tennis play. Because tennisis an untimed competition, it may last

Figure 7. 90/90 prone plyometric exercise.

Figure 8. Prone horizontal abduction plyometric exercise.

Figure 9. Reverse catch deceleration training exercise.



anywhere from 30 minutes to 5 hours(17). However, from a practicalstandpoint, we know that high-levelcompetitive tennis has some typicalpatterns that occur during matchesthat can help the strength and condi-tioning professional when designingprograms. Athletes typically encounterbetween 3 and 7 directional changesper point, rarely move more than 30yards in one direction (16,38). In addi-tion, point length averages are around6 seconds, with the majority of pointslasting less than 10 seconds, anda typical work-to-rest ratio during indi-vidual points and matches is between1:2 and 1:5 (15,16,18,19,30). All thesefactors can be used to help developtennis-specific deceleration trainingprograms.

WHAT FACTORS IMPROVE ATENNIS PLAYERS DECELERATIONABILITY?

Dynamic balance, eccentric strength,power, and reactive strength are 4major qualities that have a significantinfluence on an athletes ability to decel-erate, while maintaining appropriatebody position to execute the necessarytennis stroke and then recover for thenext stroke (Figure 4) (41). Althoughother components do contribute to anathletes ability to effectively decelerate,these 4 factors will be investigated to aidthe strength and conditioning coach indesigning effective programs.

DYNAMIC BALANCE

Dynamic balance is paramount in ten-nis, specifically during the decelerationmovement phase before or after theplayer makes contact with the ball.Dynamic balance is the ability of theathlete to maintain a stable center ofgravity while the athlete is moving(1). This ability to maintain balance ina dynamic environment allows the ath-lete to successfully use the segmentalsummation of muscular forces andmovements through the kinetic chain(13). This efficient energy transfer fromthe ground and up through the entirekinetic chain will result in a moreefficient and powerful tennis stroke,in addition to faster racket head speeds

and ball velocities. Additionally,dynamic balance can refer to the abilityduring movements of opposing musclesto work optimally together to produceuncompensated movement patterns(1). This is particularly important inthe upper extremity when proper mus-cle balance must be maintained toimprove shoulder joint stability.Although experts may not agree onthe mechanisms involved in athletespe-cific balance, the research suggests thatchanges in both sensory and motor sys-tems influence balance performance(1). The feedback obtained fromplyometric movements encompassesa number of reflexive pathwaysthat aid muscle and neural adapta-tions to accommodate unanticipated

movements (34). These adaptationsare vital for the prevention of injuriesduring practice and competition.

ECCENTRIC STRENGTH

Eccentric strength requires trainingof the muscles during the lengthen-ing phase of the muscle action. Anexample would be during the stepbefore and the loading phase ofa forehand (Figure 5). Eccentricstrengthening exercises need to beperformed both bilaterally and uni-laterally. Nearly all tennis move-ments require the athlete to loadone side of the body more than theother, and it is paramount thatthese uneven loading patterns aretrained eccentrically as well as

Figure 10. Tennis-specific reverse catch. A) Start. B) Deceleration phase.


concentrically. It is known that phys-

ically trained humans can support

approximately 30% more weighteccentrically than concentrically(6,23,40). Therefore, eccentric focusedstrength training needs to be incorpo-rated into an athletes periodized pro-gram to successfully maximize his orher athletic improvement. A secondmajor benefit of training eccentricstrength is to aid in the prevention ofinjuries (2,26). A large portion of injuriesto tennis players is attributable toinsufficient eccentric strength both inthe upper body during the decelerationof the racket after serves, groundstrokes,and volleys, as well as in the lowerbody during the deceleration of thebody before planting the feet to

establish a stable base for effectivestroke production.

Eccentric strengthening exercises havea positive effect on altering the lengthtension relationship of muscle (3). Theoptimum length of peak tension occursat longer lengths, therefore, shifting thecurve to the right (Figure 6).

Lengthtension curves for single fibers(sarcomeres), whole muscle, and singlejoints all have different shapes (3). As theresult of these different shapes, it is vitalfor the athlete to be trained at a varietyof angles and torques to stimulate adap-tations in as many muscle fibers as pos-sible to capture the greatest effect onaltering the lengthtension relationship,specifically during eccentric dominant

movements. A great review of the eccen-tric exercise literature by Brughelli andCronin (3) devised some tentative con-clusions that should be helpful whendesigning programs focused on eccen-tric strengthening to optimize the lengthtension relationship. High-intensity and higher volumeeccentric exercise result in greatershifts in optimum length Eccentric muscle actions at longerlengths result in greater shifts in opti-mum length It may be possible to produce a sus-tained shift in optimum length after 4weeks of eccentric exercise Excessive muscle damage may notneed to be induced for this shift inoptimum length to occur with eccen-tric exerciseFrom the muscle physiology litera-ture, we know that after eccentricexercise, the athletes cytoskeletal pro-teins, such as desmin and titin, are dis-rupted and degradation occurs (10),possibly as high as 30% after a singlebout of eccentric exercise (37). Thisprocess then results in a protectiveadaptation that strengthens the cyto-skeletal proteins and prevents themfrom being damaged in the future.This is one of themajor theorizedmech-anisms as to why eccentric strengthen-ing is important for injury prevention,especially during movements thatrequire rapid deceleration. Mostmuscle-related injuries occur when theyare actively lengthened (11). From theliterature, it appears that neural controlof eccentric actions is unique from con-trol of concentric actions (25). The cen-tral nervous system adjusts motor unitrecruitment, activation level, distributionof that activation, and afferent feedbackduring eccentric muscle actions (8).Therefore, specificity of muscle contrac-tion mode (i.e., eccentric, isometric orconcentric) during training is important.

POWER

Power for the tennis player is whatdirectly translates into greater rackethead speed and ball velocity. Mostforms of plyometric exercise move-ments are geared toward improvingmuscular power. Plyometric exercises

Figure 11. External rotation at 90 degrees with elastic tubing. A) Start. B) Finish.



are vital for the development ofgreat deceleration abilities througha number of separate, yet interrelatedmechanisms. Plyometric movementsinduce neuromuscular adaptations tothe stretch reflex, as well as the elastic-ity of muscle and Golgi tendon organs(GTOs) (39). The stretch reflex is ini-tiated during the eccentric loading andresults in greater motor unit recruit-ment during the ensuing concentriccontraction. GTOs have a protectivefunction against excessive tensile loadsin the muscle; however, plyometrictraining results in a degree of desensi-tization of the stretch reflex, which al-lows the elastic component of muscleto undergo a greater stretch (12).The combined adaptations resultsin a more powerful concentric con-traction which, in tennis, wouldresult in greater power and speed inrecovering from hitting one stroke tothe next. It is thought that a largeportion of muscular performancegains after plyometric movementsare attributed to neural changesrather than morphological (39). Thisimproved neuromuscular functiondirectly influences the major compo-nents needed for effective decelera-tion ability (Figure 1).

REACTIVE STRENGTH

Reactive strength has been defined asthe tcgqzaplayer rapidly drops and dur-ing the muscle contraction sequencefrom the eccentric to the concentricphase in the stretchshortening cycle

Figure 12. Romanian deadlift (RDL). A) Start. B) Finish.

Figure 13. Box jump. A) Start. B) Finish.


and is a specific form of muscle power(42). A plyometric training programthat uses lateral and multidirectionalmovements while limiting time on theground will develop reactive strengthand subsequent power outputs in themuscles and movements that are seenduring tennis play. This type of trainingdirectly relates to a tennis athlete in hisor her recovery sequences betweenshots and also during the times in a pointwhen he or she is wrongfooted andis in need of rapid change of direction.Increased muscle activity, specificallyin the form of eccentric loading, willenhance muscle stiffness. Thisincrease in muscle stiffness leads tomore force absorption in the muscu-lartendon unit rather than transmit-ted through the articular structures(32). It has been suggested that muscleactivation is a dynamic restraintmechanism that results in protectingthe joints such as the shoulder, hip,knee, and ankle (32).

PRACTICAL APPLICATIONS FORTHE TENNIS ATHLETE

Deceleration is a biomotor skill that isclosely linked to agility and multidi-rectional movement training. Assuch, it needs to be trained in a multi-focused training program with appro-priate rest periods and loads that areprogressed based on the tennis

players growth, maturation, andtraining stages. From a training per-spective, the posterior muscles of thetennis athlete need to be a focus if theathlete is to become a successfulplayer who has great decelerationability. In the lower body, the hip ex-tensors, including the glutes and ham-string muscles, need to be trainedspecifically in an eccentric mannerwith progressive increases in resis-tance. In the upper body, a majorfocus needs to be on the posterioraspect of the shoulder region, whichwill assist in the deceleration of thearm during the tennis serve, ground-strokes, and volleys. Because limiteddata are currently available on decel-eration training guidelines, it is impor-tant to monitor training closelybecause eccentric loading can causemore delayed onset of muscle sore-ness than similar concentric exercise(23). Because multiple sets of exer-cises have shown greater results thansingle sets (20), deceleration trainingshould be performed using multiplesets with varied repetition rangesbased on the age, maturation andtraining status of the athletes.

UPPER-BODY EXERCISES

This section contains 5 upper-extremity plyometric exercises. Eachexercise can be started with a small

hand-sized plyometric ball weighingapproximately 0.5 kg to start withprogression to a 1-kg ball as trainingprogresses and competency and toler-ance to the exercise is demonstratedby the player. Exercise 5 (Figure 11)does not use a weight but rathera piece of elastic tubing to providethe overload for this exercise. Theplyo dropping exercises typically use30-second sets of exercise, whereasthe reverse catching exercises usemultiple sets of 15 to 20 repetitionsto improve local muscular strengthand endurance.

Exercise 1. Exercise 1 shows the 90/90prone plyometric exercise that placesthe shoulder and upper arm ina functional position inherent in theserving motion. In this exercise,the player rapidly drops andcatches the ball as quickly as possible,with the ball moving only a few cen-timeters as it leaves the grasp of theplayer temporarily before being re-caught and dropped from the refer-ence position as pictured. Typically,multiple sets of 30 seconds are used intraining to foster local muscularendurance (Figure 7).

Exercise 2. Exercise 2 is a prone hori-zontal abduction plyometric exercisein which the athlete lies prone ona supportive surface with the shoulderabducted 90 degrees with the elbowextended. A small medicine ball isused to repeatedly drop and catchthe ball as rapidly as possible asdescribed for exercise 1 previously.By rotating the hand such that thethumb is pointing upward during thedropping and catching activity (i.e.,external shoulder rotation) this exer-cise has been found to increase activa-tion of the rotator cuff muscles(Figure 8) (24,28).

Exercise 3. Exercise 3 shows a reversecatch deceleration training exercise.In this exercise, the arm is againpositioned in 90 degrees of elevation(abduction) and 90 degrees of elbowflexion as pictured. A partner standsjust behind the player and throwsa small 0.5- to 1-kg medicine ball

Figure 14. Lateral hurdle runs with hold.



toward the players hand (30). Uponcatching the ball, the arm moves intointernal rotation until the forearm isnearly parallel to the ground, just as itis decelerated during the servingmotion functionally. The player,after decelerating the ball, rapidlyfires the ball backwards toward thepartner, performing a concentriccontraction of the rotator cuff andscapular muscles. Recent researchhas demonstrated significant in-creases in eccentric strength in theshoulder of subjects when usingthese types of exercises in a perfor-mance enhancement training pro-gram (Figure 9) (4).

Exercise 4. Exercise 4 shows a varia-tion of the reverse catch exercisewhere the athlete keeps the elbowstraight during the catching and sub-sequent release of the plyo ball tosimulate the serving motion anda PNF D2 diagonal pattern. ThePNF D2 pattern is a functional diag-onal pattern that closely simulates

the movement pattern the upperextremity goes through during thethrowing or serving motion. D2extension, which is performed con-centrically in this exercise, includesthe patterns of shoulder flexion,abduction, and external rotation,whereas the eccentric actionincurred in this exercise after thecatch of the medicine ball (D2 flex-ion) includes shoulder extension,internal rotation, and slight crossarm adduction. This pattern is chosenfor its activation pattern, whichclosely simulates the functionalthrowing or serving action, as wellas its activation of the rotator cuffand scapular muscles. Emphasis is ini-tially on the deceleration of the ball asthe arm continues forward aftercatching the ball then rapidly revers-ing direction to perform an explosiveconcentric backward throwing move-ment (Figure 10).

Exercise 5. Exercise 5 shows theexternal rotation at 90 degrees

exercise with elastic tubing. The tra-ditional way of doing this exerciseinvolves slow controlled internaland external rotation at 90 degreesof abduction. However, to increasethe eccentric or deceleration empha-sis of this exercise, a plyometric typeformat can be incorporated to addvariety. Start with tension on the tub-ing with the shoulder elevated 90 de-grees in the scapular plane (30degrees forward from the coronalplane) (Figure 11). The shouldershould be externally rotated 90 de-grees, which places the forearm ina vertical position. The athlete thenrapidly decelerates forward intointernal rotation until the forearmreaches a horizontal position. Uponreaching this position, the athletethen explosively returns the handand forearm back to the startingposition with as little pause betweenthe initial lengthening phase of theexercise and the concentric explosivephase as possible. This is repeated for

Figure 15. A) MB deceleration catch lunge (linear). B) MB deceleration catch lunge (Lateral). C) MB deceleration catch lunge (45degrees). D) MB deceleration catch lunge (cross-over).


multiple sets of 15 to 20 repetitions(Figure 11).

LOWER-BODY EXERCISES

Exercise 6. Exercise 6 shows a Roma-nian deadlift strength exercise thatworks on the muscular developmentof the hamstrings, glutes, and lowerback muscles as force is appliedduring eccentric muscle actions.Repetition ranges and time underload for this exercise should focuson both muscular strength andendurance during the training pro-gram (Figure 12).

Exercise 7. Exercise 7 shows a tradi-tional box jump with specific empha-sis on the landing phase. It isimportant to have the athlete landin a strong squat position, whichdevelops eccentric strength andrapid deceleration abilities. A moreadvanced athlete who has developedappropriate lower body strength canadvance to performing a depthbox jump. However, for youngerathletes, or athletes with limitedstrength in the lower body, a depthjump should only be performedafter appropriate training andlower-body strengthening exercises(Figure 13).

Exercise 8. Lateral Hurdle Runs withHold. This is a traditional lateralfocusedplyometric movement that works onthe muscles of the lower body, froma stretch shortening perspective, butalso at the end of each set of 4 hurdlesthe athlete needs to decelerate andcome to a complete stop and holdthe lowered center of mass positionfor 2 complete seconds before reaccel-erating back into the exercise(Figure 14).

Exercise 9. Medicine Ball DecelerationCatch and Lunge (Linear, Lateral, 45Degrees, and Cross-Over). This exercisefocuses on the athlete catchinga relatively heavy medicine ballduring the eccentric portion of thelunge and then releasing it duringthe concentric portion of thelunge. The catching aspect of themovement loads the eccentric por-tion (Figure 15).

Mark Kovacs isthe Manager ofSport Science forthe United StatesTennisAssociation.

Paul Roetert isthe ManagingDirector ofPlayer Develop-ment for theUnited StatesTennisAssociation.

Todd S.Ellenbecker isthe NationalDirector of Clini-cal ResearchPhysiotherapyAssociates and isthe Director ofSports Medicinefor the ATP Tour.

REFERENCES1. Bressel E, Yonker JC, Kras J, and

Heath EM. Comparison of static and

dynamic balance in female collegiate

soccer, basketball and gymnastics athletes.

J Athletic Training 42: 4246, 2007.

2. Brockett CL, Morgan DL, and Proske U.

Predicting hamstring strain injury in elite

athletes. Med Sci Sports Exerc 36: 379

387, 2004.

3. Brughelli M and Cronin J. Altering the

length-tension relationship with eccentric

exercise. Sports Med 37: 807826, 2007.

4. Carter AB, Kaminski TW, Douex AT, and

Knight CA. Effect of high volume upper

extremity plyometric training on throwing

velocity and functional strength ratios of the

shoulder rotators in collegiate baseball players.

J Strength Cond Res 21: 208215, 2007.

5. Chandler TJ, Kibler WB, Stracener EC,

Ziegler AK, and Pace B. Shoulder strength,

power, and endurance in college tennis

players. Am J Sports Med 20: 455458,

1992.

6. Ellenbecker TS, Davies GJ, and

Rowinski MJ. Concentric versus eccentric

isokinetic strengthening of the rotator cuff.

Am J Sports Med 16: 6469, 1988.

7. Elliott B and Anderson J. Biomechanical

performance models: The basis for stroke

analysis. In: ITF Biomechanics of

Advanced Tennis. Elliott B, Reid M, and

Crespo M, eds. London: The International

Tennis Federation, 2003. p. 157175.

8. Enoka RM. Eccentric contractions require

unique activation strategies by the nervous

system. J Appl Physiol 81: 233923346,

1996.

9. Fleisig GS, Andrews JR, Dillman CJ, and

Escamilla RF. Kinetics of baseball pitching

with implications about injury mechanisms.

Am J Sports Med 23: 233239, 1995.

10. Friden J and Lieber R. Eccentric

exerciseinduced injuries to contractile and

cytoskeletal muscle fibre components.

Acta Physiol Scand 171: 321326, 2001.

11. Garrett W. Muscle strain injuries. Am J

Sports Med 24: S2S8, 1996.

12. Hutton RS and Atwater SW. Acute and

chronic adaptations of muscle

proprioceptors in response to increased

use. Sports Med 14: 406421, 1992.

13. Kibler WB. Clinical biomechanics of the

elbow in tennis: implications for evaluation

and diagnosis. Med Sci Sports Exerc 26:

12031206, 1994.

14. Komi PV and Bosco C. Utilization of stored

elastic energy in leg extensor muscles by

men and women.Med Sci Sports 10: 261

265, 1978.

15. Kovacs M. Energy system-specific training

for tennis. Strength Cond J 26: 1013,

2004.

16. Kovacs M, Chandler WB, and Chandler TJ.

Tennis Training: Enhancing On-Court

Performance. Vista, CA: Racquet Tech

Publishing, 2007.

17. Kovacs MS. Tennis physiology: training the

competitive athlete. Sports Med 37: 111,

2007.

18. Kovacs MS. Applied physiology of tennis

performance. Br J Sports Med 40: 381

386, 2006.

19. Kovacs MS. A comparison of work/rest

intervals in mens professional tennis. Med

Sci Tennis 9: 1011, 2004.

20. Kraemer WJ and Ratamess NA.

Fundamentals of resistance training:

Progression and exercise prescription.

Med Sci Sports Exerc 36: 674688, 2004.



21. Kyrolainen H, Komi PV, Hakkinen K, and

Kim DH. Effects of power-training with

stretch-shortening cycle (SSC) exercises

of upper limbs in females. J Strength Cond

Res 12: 248252, 1998.

22. Lees A. Technique analysis in sports: A

critical review. J Sports Sci 20: 813828,

2002.

23. Lindstedt SL, LaStayo PC, and Reich TE.

When active muscles lengthen: properties

and consequences of eccentric

contractions. News Physiol Sci 16: 256

261, 2001.

24. Malanga GA, Jenp YP, Growney ES, and

An KN. EMG analysis of shoulder

positioning in testing and strengthening the

supraspinatus. Med Sci Sports Exerc 28:

661664, 1996.

25. Moore CA and Schilling BK. Theory and

application of augmented eccentric

loading. Strength Cond J 27: 2027,

2005.

26. Proske U, Morgan DL, Brockett CL, and

Percival P. Identifying athletes at risk of

hamstring strains and to protect them. Clin

Exp Pharmacol Physiol 31: 546550,

2004.

27. Reid M, Chow JW, and Crespo M.

Muscle activity: an indicator for training.

In: ITF Biomechanics of Advanced

Tennis. Elliott B., Reid M., and

Crespo M., eds. London: The

International Tennis Federation, 2003. p.

111136.

28. Reinhold MM, Wilk KE, Fleisig GS,

Zheng N, Barrentine SW, and

Chmielewski T. Electromyographic analysis

of the rotator cuff and deltoid musculature

during common shoulder external rotation

exercises. J Orthop Sports Phys Ther 34:

385394, 2004.

29. Roetert EP and Groppel JL, eds. World-

Class Tennis Technique. Champaign, IL:

Human Kinetics, 2001.

30. Roetert EP and Ellenbecker TS. Complete

Conditioning for Tennis (2nd ed.).

Champaign, IL: Human Kinetics, 2007.

31. Roetert EP, Ellenbecker TS, and

Brown SW. Shoulder internal and external

rotation range of motion in nationally

ranked junior tennis players: A longitudinal

analysis. J Strength Cond Res 14: 140

143, 2000.

32. Sinkjaer T and Arendt-Nielsen L. Knee

stability and muscle coordination in

patients with anterior cruciate ligament

injuries: an electromyographic approach.

J Electromyogr Kinesiol 1: 209217,

1991.

33. Stone MH, OBryant HS, McCoy L,

Coglianese R, Lehmkuhl M, and

Schilling B. Power and maximum strength

relationships during performance of

dynamic and static weighted jumps.

J Strength Cond Res 17:15271533,

2003.

34. Swanik CB, Lephart SM, Giannantonio FP,

and Fu FH. Reestablishing proprioception

and neuromuscular control in the ACL-

injured athlete. J Sport Rehabil 6: 182

206, 1997.

35. Swanik KA, Lephart SM, Swanik CB,

Lephart SP, Stone DA, and Fu FH. The

effects of shoulder plyometric training on

proprioception and selected muscle

performance characteristics.

J Shoulder Elbow Surg 11: 579586,

2002.

36. Swanik KA, Swanik CB, Lephart SM, and

Huxel K. The effects of functional training

on the incidence of shoulder injury in

intercollegiate swimmers. J Sports Rehabil

11: 142154, 2002.

37. Trappe T, Carrithers J, White F, Lambert CP,

Evans WJ, and Dennis RA. Titin and nebulin

content in human skeletal muscle following

eccentric resistance exercise.Muscle Nerve

25: 289292, 2002.

38. Weber K, Pieper S, and Exler T.

Characteristics and significance of running

speed at the Australian Open 2006 for

training and injury prevention. Med Sci

Tennis 12: 1417, 2007.

39. Wilk KE, Voight ML, Keirns MA,

Gambetta V, Andrews JR, and Dillman CJ.

Stretchshortening drills for the upper

extremities: Theory and clinical application.

J Orthop Sports Phys Ther 17: 225239,

1993.

40. Wilson GJ, Murphy AJ, and Pryor JF.

Musculotendinous stiffness: Its relationship

to eccentric, isometric, and concentric

performance. J Appl Physiol 76: 2714

2719, 1994.

41. Young W and Farrow D. A review of agility:

Practical applications for strength and

conditioning. Strength Cond J 28: 2429,

2006.

42. Young W, Wilson G, and Byrne C.

Relationship between strength qualities

and performance in standing run-up vertical

jumps. J Sports Med Physical Fitness 39:

285293, 1999.

43. Young WB, McDowell MH, and

Scarlett BJ. Specificity of sprint and agility

training methods. J Strength Cond Res 15:

315319, 2001.


Date post:	05-Jan-2016
Category:	Documents
Upload:	peterashcroft72677
View:	19 times
Download:	0 times

Efficient Deceleration the Forgotten Factor in.5

Documents