br med bull 2009 frisch bmb_ldp034

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Injuries, risk factors and prevention initiatives

in youth sport

Anne Frisch, Jean-Louis Croisier, Axel Urhausen, Romain Seil,

and Daniel Theisen*Sports Medicine Research Laboratory, Public Research Centre for Health, 1a-b, rue ThomasEdison, L-1445 Strassen, Grand-Duchy of Luxembourg; Centre de lAppareil Locomoteur, deMedecine du Sport et de Prevention du Centre Hospitalier de Luxembourg, Luxembourg, andDepartement des Sciences de la Motricite, Faculte de Medecine, Universite de Liege, Belgium

Background: Sports injuries in young athletes are a public health issue which

deserves special attention. Effective prevention can be achieved with training

programmes originating from the field of physical therapy and medicine.

Sources of data: A systematic literature search on injury prevention in youth

sport was performed in the MEDLINE database.

Areas of agreement: For prevention programmes to reduce sports injuries,

critical factors must be considered, such as training content, duration and

frequency, as well as athlete compliance.

Areas of controversy: Home-based programmes could be inferior to supervised

training, but are efficient if compliance is high. So far prevention programmes

have focused on team sports and their efficiency in individual sports remains to

be proven.

Growing points: Active prevention programmes focusing specifically on the

upper extremity are scarce. Initiatives enhancing the awareness of trainers,

athletes and therapists about risk factors and systematic prevention measures

should be encouraged.

Keywords: sports injuries/young athlete/prevention strategies/compliance/risk factors

British Medical Bulletin 2009; 127

DOI:10.1093/bmb/ldp034

& The Author 2009. Published by Oxford University Press.

All rights reserved. For permissions, please e-mail: [email protected]

Accepted: August 20,

2009

*Correspondence to:

Daniel Theisen, Sports

Medicine Research

Laboratory, CRP-Sante,

1a-b, rue Thomas Edison,

L-1445 Strassen, Grand-

Duchy of Luxembourg.

E-mail: daniel.theisen@

crp-sante.lu

British Medical Bulletin Advance Access published September 24, 2009


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Introduction

Promotion of a physically active lifestyle is encouraged worldwide, par-ticularly with regard to the many health benefits.1 In children and adoles-cents, regular sports practice facilitates the development of fundamental

movement skills,2

helps prevent obesity and its long-term consequences3

and has long-lasting benefits on bone health.4 Unfortunately, increasedintensity and volume of sport practice lead to a higher rate of acute andoveruse injuries. For the young athlete, the consequences of sports inju-ries could be numerous, ranging from re-injury to career-ending.5

Long-term impacts of sports injuries are frequently found in adulthood,such as an accelerated development of osteoarthritis.6

In addition to the potentially long-term outcomes of sports injurieson later life, the related healthcare costs constitute a substantial econ-omic burden. In a recent study, Cumps et al.7 showed that the ensuing

total direct medical costs of sports injuries in Flandren (i.e. rehabilita-tion, medical care, hospitalization, medication, bandages, transport,crutches) amounted to 15 027 423.00], which represents 0.07 0.08%of the total budget spent on health care. In the USA, the estimatedtotal hospital charges for sports injury hospitalizations among 5 18-year-olds were $485 million over a period of 4 years, with a steadyincrease each year.8 The highest medical costs are mostly found forknee injuries, especially for anterior cruciate ligament (ACL) injuries.7,8

The costs for one ACL surgery plus rehabilitation were estimated to upto $17 000. Gianotti et al.9 analysed knee ligament injuries in NewZealand and found that the mean treatment costs were $885 for non-surgical knee injuries, $11 157 for ACL surgeries and $15 663 forother knee ligament surgeries. The socio-economic impact should alsobe viewed under the light of indirect costs of sports injuries, such asabsence from work and long-term health consequences, which add tothe direct costs.7

Reduction of only a moderate proportion of all sports injuries is ofsignificance for the young athletes health and could have a long-termeconomic impact regarding health-care costs.10 It is therefore importantto convince medical doctors, physical therapists, trainers and coaches,as well as the athletes themselves, of the necessity to implement active

prevention measures into their therapy and training programmes, thusdecreasing the (re-)injury rate and enhancing athletic performance.Indeed, recent scientific literature based on a systematic injury preven-tion approach suggests that well-designed programmes do have positiveeffects, provided that a number of conditions are fulfilled.

Van Mechelen et al.11 proposed a general four-step model (Fig. 1) forsports injury surveillance. The first step comprises the description and

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the extent of the injury problem. In a second phase, the aetiology andmechanisms of sports injury are being investigated. A third stage con-cerns the introduction of preventive measures, which will then beassessed regarding their effectiveness by repeating step 1. The purposeof this paper is to review the state-of-the-art knowledge on injury pre-vention in child and youth (,19 years) sports based on that model. Inthe first part, the incidence and frequency of particular sports injurieswill be briefly recalled, highlighting the specificities of the young agegroup related to biological maturation. The second part will discussintrinsic risk factors of that population, with special emphasis on thosewhich are modifiable and can be targeted by intervention. In the lastpart, active prevention programmes will be critically presented regard-

ing their implementation, characteristics and efficiency. This analysiswill make it possible for practitioners of different areas to draw rel-evant recommendations for their work.

Search strategy and methods

A systematic search of relevant publications was performed for thesection on active prevention strategies via the MEDLINE database(1966 May 2009). The keywords used were adolescent OR youth

AND sports injury AND prevention, yielding a total of 1953 hits.Additional searches were performed in the authors personal databases.Relevant papers were selected on the basis of the following criteria:

exclusive focus on organized sports;

separate results for young athletes under the age of 19 years;

longitudinal studies: only prospective designs;

major focus on intrinsic risk factor;

Fig. 1 Sequence of prevention in four steps, adapted from Van Mechelen et al.11

Preventing sports injuries in the young athlete

British Medical Bulletin 2009 Page 3 of 27


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intervention studies using active prevention programmes;

search limited to English papers only.

Figure 2 provides an overview of the search strategy used. On the basisof these selection criteria, 14 studies were retained for further analysis.

Injuries in youth sport

Before investigating the effectiveness of prevention measures, it is man-

datory to get a global overview of the injury problem. This is, however,a difficult task for any person confronted with the considerableamount of literature that has accumulated in recent years. It appearsthat the sports injury issue can be addressed from multiple points ofviews (Fig. 3). Most studies1224 have focused on one specific sport dis-cipline highlighting injuries related to the inherent characteristics of thesport in question. Other investigations2528 have addressed a particularbody region or injury type, which again only provides a rather limitedview of the sports injury problem. The aim of this section is thereforeto briefly summon up the main acute and chronic injuries related to

youth sports to present a general picture, taking into account the speci-ficity of this population, the sport-specific context and the anatomicallocation. Previous reports have shown rates of injury per 1000exposure hours between 0.5 and 34.4, with highest rates for boys in icehockey (534.4 injuries/1000 h), rugby (3.413.3 injuries/1000 h) andsoccer (2.3 7.9 injuries/1000 h), and for girls in soccer (2.5 10.6injuries/1000 h), basketball (3.6 4.1 injuries/1000 h) and gymnastics(0.5 4.1 injuries/1000 h).5,29 For a more detailed analysis of injury

Fig. 2 Flow-chart illustrating the search strategy used for investigations dealing with active

prevention strategies.

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incidence rates in different sport disciplines, the reader is kindly

referred to some excellent reviews that have been recently pub-lished.5,2931

When analysing different studies on sports injury prevention, somemethodological issues arise, the most important being the way ofreporting injuries (e.g. absolute number of injuries, injury proportionor injury incidence) as well as injury definition.32 The latter mayexplain part of the sometimes large variations in the reported injuryrates.33 The time of sports practice has been frequently used in the lit-erature with minor distinctions,33,34 such that some caution is war-ranted when interpreting the results presented here (Tables 1 and 2).

Recently, consensus statements on injury definitions and data collectionprocedures have been published for soccer35 and rugby.36

Epidemiology of acute injuries

The main acute injuries in youth sports are sprains, strains, fractures,dislocations and contusions. Overall, sprains account for 2748% ofall injuries in the young athlete,19 21,37 with the ankle and knee beingthe two most common anatomical locations for sprains.20 Ankle andknee sprain rates are particularly high in sports involving sharp cutting

manoeuvres, running and pivoting movements, stopping and startingmovements or jumps and landings on one foot. Typically, disciplinessuch as tennis, volleyball, handball, basketball and soccer are especiallyconcerned here.18,23,37,38 In youth soccer, ankle sprain incidencereaches up to 1.50/1000 h.39 These results are comparable to the 1.56ankle sprains/1000 h found in youth basketball.40 Considering kneesprains, higher incidences were found for females compared withmales, both in soccer39 (0.72/1000 h versus 0.14/1000 h) and in

Fig. 3 Multiple perspectives to analyse the sports injury problem.




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basketball41 (0.09/1000 h versus 0.02/1000 h). Finger injuries,especially finger sprains, are frequent in team ball sports such asnetball42 (15%), basketball16 (4.9%) and handball21 (1018%).Strains are very common in adolescent soccer, where they account for1753% of all injuries.17,20,34,37 The groin region seems to be most

often concerned (0.57 strains/1000 h), followed by the thigh region(0.36 strains/1000 h) and the calf and back regions (both 0.21 strains/1000 h).39 For some sports, concussions are relatively frequent. Forsoccer, the incidence found was 0.36 concussions/1000 h,39 whereasfor ice hockey, it was 0.74 concussions/1000 h,15 thus representingthe most common specific injury type (18% of all injuries).

Fractures were found to represent between 2% and 37% of all inju-ries related to soccer,17,20,34,37,43,44 mostly at the wrist, foot and ankleregion.20 A similar large proportion was found in basketball (17 36%),43 volleyball (7 21%)43 and gymnastics (2 40%).12,19,43

Dislocations accounted for 2939% of all injuries in basketball,43 for1435% in volleyball,43 for 135% in gymnastics19,43 and for 0.330% in soccer.17,20,43 In the young athlete, dislocations are often recur-rent and can lead to post-traumatic instability.26,45 Contusions are alsorelatively frequent, especially in team sports and gymnastics (up to over50%).43

Epidemiology of chronic injuries

Overuse injuries are due to repetitive stress on a biological tissue,which leads to microtrauma in this specific body region. In adolescentsoccer, overuse injuries account for 10 34% of all reported inju-ries.20,22,37,39,46 In youth basketball, 38% overuse injuries werereported,16 whereas in youth handball, they represented 7 21% oftotal injury number.21,24 Many overuse injuries in adolescents are dueto traction apophysitis.47

Some chronic injuries are specifically associated with children andadolescents. Concerning the upper extremity, the main overuse injuriesare the little leaguers shoulder, the rotator cuff tendinopathy and the

little leaguers elbow. The former is a stress fracture of the proximalepiphyseal plate,45 which is specific to young overhead sports athleteswith open growth plates, involved in sports such as baseball, volleyballand tennis.48 Shoulder impingement and rotator cuff tendinopathiesare frequent in swimmers due to excessive internal shoulder rotation.Rotator cuff tendinopathy also occurs as a result of chronic repetitivehitting and overhead serving in young tennis players.49 Little leaguerselbow is a traction apophysitis of the flexor/pronator muscles origin on

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the medial epicondyle and can be found in young baseball players, per-forming excessive throwing training.50

Regarding the lower extremity, a common cause for anterior kneepain in young athletes is the OsgoodSchlatter lesion, a traction apo-physitis of the tibial tuberosity. It is mostly found in children who are

in a growth spurt and engaged in cutting and jumping sports, such assoccer, basketball, gymnastics and volleyball.48,50,51 In elite juniorfigure skating, the OsgoodSchlatter disease was found in 9% of allthe girls and 14% of all the boys.14 Kujala et al.27 showed that 21% ofthe active student population suffered from OsgoodSchlatter and thatthe knee pain caused complete cessation of training for an average of3.2 months over a 5-year period. At the ankle, Severs disease is fre-quent in young athletes participating in basketball, soccer, track andother running activities.48 This calcaneal apophysitis affects the inser-tion of the Achilles tendon and the plantar fascia50 and is secondary torepetitive microtrauma or overuse of the heel. Severs disease is thesecond most common osteochondrosis found in the younger athleteafter the OsgoodSchlatter lesion. Investigating young soccer playersaged 919 years, Price et al.52 reported that OsgoodSchlatters andSevers disease accounted for 5% of all injuries. In the age group of1113 years, these two conditions accounted even for 14% of all inju-ries. Another specific chronic injury at the knee joint in adolescence isthe SindingLarsenJohansson disease, a tensile stress that affects theproximal attachment of the patella tendon.51

Stress fractures also belong to the overuse injury category. Owing tomechanical overloading the balance between osteoclastic resorption and

bone formation is disrupted. In tennis, stress fractures are often foundat the lower extremity, more precisely at the foot, where the fifth meta-tarsal, the metatarsal diaphysis and navicular neck are most often con-cerned.49 In gymnastics, most stress fractures were found at the spine(42%), followed by the lower extremity (35%) and the upper extremity(23%).13 Stress fractures at the lumbosacral spine are also called spon-dylolysis. They are often secondary to repetitive hyperextension of thespine, as found in gymnastics, ballet, volleyball, diving and serving intennis.45 In basketball, stress fractures of the lower limb were found tobe the third most frequent diagnosis (5.4%) after lateral ankle sprains

and patellar tendinitis.16

In elite junior skating, all stress fractures werelocated at the lower limb, except one that was found at the lumbarspine.14 Stress fractures were the most frequent overuse injury in femaleskaters with 19.8%,14 whereas in male skaters they amounted to13.2%, the third most frequent diagnosis of overuse injuries. Generally,female athletes could potentially be more prone to stress fractures thanmales,13,14,47 an aspect that will be further addressed below.




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Long-term consequences of sports injuries

The immediate outcome of a serious acute or chronic injury is theinterruption of sports practice. A severe injury immobilizes the athleteup to several months and may require surgery or/and intensive and pro-longed rehabilitation. On a long-term basis, the consequences of asports injury may include decreased sports participation in later life, aswell as loss of function and chronic pain, as discussed below. However,the literature on long-term consequences of injuries in youth sports isscarce, most investigations having focused on the adult population.Furthermore, only few types of injuries have been followed up on along-term basis, which precludes any detailed analysis in relation to thedifferent types of injuries specific to the younger population.

The injury type that has received most attention is the knee sprain,resulting in ACL or meniscus tears. Gonarthrosis, as diagnosed by radi-ography, is significantly increased after all knee injuries compared with

the uninjured joint of the same patient.53 Half of the patients with adiagnosed ACL or meniscus lesion have osteoarthritis with associatedpain and functional impairment 1020 years after the diagnosis.54 Inoperatively treated handball players, the rate of return to sport at pre-injury levels was relatively good (58%), but the re-injury rate was ashigh as 22%, with half of the players reporting pain, instability orreduced range of motion 611 years after their ACL injury.55 A recentstudy56 showed that on an average 11.5 years after ACL reconstruction,1427% of the patients suffered severe loss of function and some 16%declared having rigorously modified their lifestyle. Among a group of

non-operated children (average age 10.1 years) with ACL injury, 35%had not returned to their pre-injury activity level after an average of3.9 years.57

The consequences of ankle sprains and shoulder dislocations havealso been investigated on a long-term basis, but not as frequently asknee injuries. In a group of young patients (mean age 20 years) fol-lowed up 2.5 years after inversion ankle injury without surgery, 74%were found to have persisting symptoms such as pain, perceivedinstability, weakness or swelling, and 16% were unable to return totheir original sport.58 No relation was found between age, sex and typeof sport with respect to long-term consequences in that study. Another5-year follow-up of the functional outcome after surgery of chronicankle instability revealed that only half of the patients regained theirpre-injury ankle function.59 A major long-term risk after anteriorshoulder dislocation is chronic instability. Re-dislocation rate afterprimary traumatic dislocation ranges from 14%60 to 67%61 after 12and 5 years follow-up, respectively, often associated with functionalimpairment.

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From the preceding discussion, it appears that the long-term conse-quences of a severe injury can be substantial. Although most resultspresented above stem from the young adult population, it is likely thatthey also apply to children and adolescents. It should be noted,however, that the literature lacks systematic long-term prospective

follow-ups of sports injuries in the younger population. Furthermore,concerning chronic injuries in youth sports, long-term impacts on laterlife do not seem to have been investigated and could represent a fruitfularea for future research.

Intrinsic risk factors

The second step of van Mechelens sequence of prevention consists inthe description of the aetiology and mechanisms of injury (cf. Fig. 1),

which are population-specific. Risk factors that could increase thepotential for sports injuries may be qualified as extrinsic (environment-dependent) or intrinsic (athlete-dependent). Extrinsic factors that influ-ence sports injury risk include sports context, protective equipment,rules and regulations, playing surface and coaching education andtraining.30,31 They will not be further developed here, because ourmain focus is on intrinsic risk factors. Some intrinsic risk factorscannot be changed and will only be addressed briefly hereafter. Othersare potentially modifiable, which is of specific interest in the injury pre-vention context. The identification of intrinsic factors which could bepotentially altered forms the basis for designing effective preventionprogrammes.

Non-modifiable risk factors

The risk factor most consistently associated with a greater injury risk isprevious injury. Considering all injuries, soccer players with a historyof injury had a 1.739 to 3.044 times greater risk to sustain a new injury.When specifically looking at ankle sprains in youth soccer, Tyleret al.62 found an even greater relative risk of 6.5 associated with pre-

vious injury. Across different sport disciplines, McHugh et al .63

reported that the association between previous injury and injury occur-rence was significant, but only for male athletes.

The young athlete is particularly vulnerable to sports injuries becauseof the physical and physiological processes of growth.50 Body areasespecially affected in adolescents compared with adults are the bonetissue and the muscle-tendon units. The muscle-tendon units elongatesecondarily in response to bone growth leading to tightness of the




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muscles, especially those muscles which cross two joints, such as therectus femoris and gastrocnemius.47 Even if the metaphysis of longbones is more flexible and elastic in children than in adults, resulting ingreater bone deflection without fracture,45 there are two areas whichare especially susceptible to fractures. First, there is the line of weak-

ness between the epiphyseal plate and the formed bone. Second, thereis the apophyseal cartilage, which is often exposed to high pullingaction from the muscle-tendon unit, resulting either in acute avulsionfracture or in traction apophysitis, depending on whether the musculartraction applied is sudden and intense or chronic and repetitive.47

Growth plates in the epiphyseal regions may be injured by repetitivephysical loading and stress. These physeal injuries could produce per-manent injury to the cells in the zone of hypertrophy resulting ingrowth disturbance.64 Bailey et al.25 demonstrated that the incidence offracture of the distal end of the radius was highest at the time of peakvelocity of growth in both sexes. Thus, they concluded that during theadolescent growth spurt, there is a discrepancy between bone growthand bone mineralization, which results in a temporary period of rela-tive weakness of the bone. In a recent study, Sugimori et al.28 alsoshowed that the incidence of fractures in a large cohort of Japanesechildren was highest at the age of growth spurt.

Considering the influence of gender, girls seem to be more prone forsome injuries than boys. For example, in figure skating, the relativenumber of stress fractures (with respect to the numbers of athletes) was11% in girls, but only 8% in boys.14 In gymnastics, an even greaterdifference was found, with 30% for girls versus 21% for boys,13 which

could reflect different practice patterns. Unfortunately, none of the twostudies reported whether these differences were statistically significant,so the answer is not definite. Regarding knee injuries, especially ACLinjuries, girls were found to have a significantly higher incidence thanboys [0.43 injuries/1000 athletes exposures (AE) versus 0.09 injuries/1000 AE].65 Other studies further suggest that ankle injuries are morefrequent in girls than in boys.66,67 Possible reasons for higher injuryrisk in girls have been put forward, such as greater joint laxity,68 lowermuscle strength30,67 and poorer proprioception and coordination.38

Finally, there are maturity-associated variations that may influence

sports injury risk.64

The adolescent athlete is more susceptible to injurythan the prepubescent athlete because circulating androgens promotethe fast development of muscle mass and enhance movement velocityand power. These rapid changes are likely to influence self-control andrisk perception. Additionally, because of the non-linear growthprocess, children of the same chronological age may vary considerablyin biological maturity status. As a consequence, there are early and latematurity children. As classification for participation in youth sport still

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relies on chronological age, great variations with respect to height andweight can be found within a team, which increases the risk of sportsinjuries.64

Modifiable risk factors

Beside the non-modifiable risk factors, some authors have pointed outspecific risk factors in children and adolescents that can be modified byprevention.2931 Potentially implicated factors are fitness level, flexi-bility, muscle strength, joint stability, balance, coordination, psycho-logical and social factors.30 Concerning cardiovascular fitness, Heidtet al.69 showed that preseason conditioning significantly lowered injuryincidence in female adolescent soccer players. Regarding muscle flexi-bility, it has been found that inflexible muscles can produce pain onthe opposite side of a joint; in competitive swimmers, tightness of theposterior shoulder muscles was associated with anterior impinge-ment.47 Moreover, as previously discussed, inflexible muscles couldcause episodes of traction apophysitis and of overuse syndromes relatedto excessive strain, but this hypothesis still remains to be tested.47

Flexibility deficits, which are particularly common in adolescents suf-fering from overuse injuries, could be improved by regular stretchingexercises. Stretching following appropriate warm-up prior to athleticactivity may also prevent muscular injuries as was concluded in arecent review article.70

The high incidence of ACL injuries in females has lead Hewett

et al.38 to evaluate neuromuscular control and joint loads in 205 youngfemale athletes participating in soccer, basketball or volleyball. Theyused three-dimensional kinematics and kinetics to evaluate perform-ance during a standardized jump-landing task. Those athletes whoacquired a confirmed ACL injury during the 13-month follow-up hadsignificantly different pre-study knee posture and loading character-istics compared with the athletes who did not develop an ACL rupture.The knee abduction angle during landing was significantly greater inACL-injured compared with uninjured players. Moreover, ACL-injuredathletes had a 2.5 times greater knee abduction moment and 20%

higher ground reaction force than their uninjured counterparts. Hence,female athletes with increased dynamic valgus and high abductionloads are at increased risk for ACL injury.

Balance and coordination have been evaluated in high-school basket-ball players in a prospective follow-up study.40 Subjects who demon-strated poor balance (high postural sway scores) had nearly seven timesas many ankle sprains as subjects who had good balance (low posturalsway scores). As a result, the authors concluded that preseason balance




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measurement (postural sway) could serve as a predictor of ankle sprainsusceptibility. Similar conclusions were reached in another study,71

where ankle injuries were more commonly found in physical educationstudents with decreased postural control.

Considering the influence of psychological factors on sports injuries,

several studies suggest that life stress could be a significant predictor ofinjury.7275 For example, major life events, such as the death of a closefriend or family member, or the separation from girl/boy-friend, couldincrease the risk for a sports injury by up to 70%.72 Steffen et al.72

showed that injured soccer players had undergone significantly morestressful life events than the uninjured players. Beside life stress, copingresources, personality traits and competitive anxiety could have aneffect on sports injuries, as discussed in a recent review.74 Williams andAnderson76 have shown that the response to life stress is modulated bythe personality of the athlete, the history of stressors and the copingresources. These factors could be easily evaluated by means of standar-dized questionnaires. Although athlete personality and history of stres-sors cannot be modified, psychological interventions could be useful inimproving the athletes attitude and coping resources. This discussionis however beyond the scope of the present review.

Interventions for sports injury prevention

The previous section has described a series of intrinsic risk factors thatare potentially modifiable. They are the specific focus of interventions

aiming at preventing sports injuries and appear in step 3 of vanMechelens prevention model (Fig. 1). The efficiency of such preventionprogrammes must, of course, be evaluated using injury statistics from along-term prospective follow-up (step 4 of the injury preventionmodel).

Basically, there are two different kinds of prevention strategies, thepassive and the active. Passive strategies do not require active adap-tations from the athlete during practice. Once the prevention strategy isadopted (e.g. compliance with new rules or wearing protective equip-ment),77,78 the athlete is automatically protected. In contrast, active

strategies imply that the athlete cooperates and modifies his behaviourwithin the sports context. An example of an active prevention pro-gramme is the 11-programme, designed by the FIFA-MedicalAssessment and Research Centre (F-MARC).79 This intervention hasbeen developed in cooperation with international experts. It promotesfair play and encompasses 10 sets of exercises which focus on corestabilization, eccentric training of thigh muscles, proprioceptivetraining, dynamic stabilization and plyometrics with straight leg

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alignment. More recently, a revised version of this programme (11)has been successfully applied on young female soccer players,37 as willbe detailed later on.

In this paper, only studies dealing with active prevention strategiesare presented based on our systematic literature search (cf. introduc-

tion). Before describing different programmes in greater detail, it isworthwhile to discuss a number of issues related to the implementationof such programmes into the athletes training schedule.

Challenges to implement injury prevention strategies

The effectiveness of an injury prevention programme depends not onlyon its content but also on the success of its more or less permanentacceptance and implementation within the sports community. Greatefforts are sometimes required to convince trainers and coaches toadopt a specific prevention programme over longer periods of time.Compliance to prevention training at the level of the team as well asthe level of the individual athlete is critical. Therefore, the organizationof large-scale randomized controlled trials demands a long preparationtime and many resources.

One of the first premises for an effective prevention programme is thecooperation from trainers. The latter must be fully briefed with respectto programme duration and content, correct execution of exercises, fre-quency and the importance of athlete compliance. The interventionprogramme should be designed in such a way that it does not interfere

too heavily with the usual training activities. Furthermore, additionallyrequired material (exercise books and DVDs, balance mats, wobbleboards etc.) should be made available taking into account the financialimplications.

In some studies, teams are supplied with instructional videotapes atthe beginning of the intervention training, demonstrating the correctexecution of the prevention exercises.37,55,65,80 Sometimes the athletesare asked to control each other by watching the accomplished exerciseand giving each other feedback.37,81,82 Regular checks from the studyinstructors are nevertheless needed to verify the appropriate execution

of the programme, the implementation of which can take up to 1.5months.82

The success of an injury prevention programme also greatly dependson compliance of the individual athletes to the intervention, as will bediscussed hereafter. Adherence can be influenced by the sport- orstudy-specific context, since in team sports the trainer or coach bearsgreater responsibility, whereas in individual sports the athletes owncommitment is critical. Another difficulty of evaluating the role of




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compliance results from the fact that some studies do not specify whatkind of compliance was evaluated. Different indexes have beenreported, such as the percentage of training sessions in which the pro-gramme was used (training session compliance),37,82 compliance ofparticipants to the training sessions (participant compliance)37,65,82 84

or the percentage of teams adhering to the programme (team compli-ance)80,81 (Tables 1 and 2). None of these variables necessarily reflectthe compliance of the individualathletes to the entire intervention pro-gramme. These aspects are of particular importance when interpretingthe results of sports injury prevention initiatives. Close collaborationwith the study group is also needed regarding data collection and deter-mines, what has been termed, the collecting data compliance.85 Thelatter is also important regarding the gathering of information aboutsports injuries, which requires prior briefing or even training of one orseveral local contact persons.

Outcome of prevention initiatives

Injury prevention programmes focusing on the young athlete have beenmainly tested in the context of team sports, such as soccer,37,80,82,86 88

basketball,83 handball81,89,90 and multiple sports.65,84,85 To theauthors knowledge, no prevention programmes for individual sportshave been presented in the literature. This could have practical reasons,in that implementation and high compliance are easily achieved inteam sports compared with individual disciplines. Furthermore, in

team sports, more athletes can be targeted at one time.Tables 1 and 2 summarize the main results from studies investigating

the effects of different prevention programmes. In Table 1, only resultswith a significant positive effect on sports injuries are reported,whereas Table 2 reviews observations with no significant reduction ofinjuries. Regarding content, it appears that injury prevention in youthsports has mainly focused on the lower extremity and the trunk.Components which often appear in successful programmes are plyo-metrics,37,65,69,80 functional strength24,37,65,69,80,81,86,89,90 or condition-ing exercises,69 sport-specific agility drills,37,69,80 activities to improve

balance and body control37,81,83 85,87 90

and flexibility exer-cises.65,69,80 Great emphasis is generally placed on neuromuscularcontrol, core stability, lower limb alignment, hip control and properlanding technique (e.g. knee over toe position, decreased impactforces, bilateral landing). Close supervision and feedback (oral andvisual via ordinary video analysis) by a proficient trainer or at least bypeers seem to be of particular importance to guarantee properexecution of the exercises.37,81 This critical aspect may put home-based

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Table 1. Summary of studies reporting on successful active prevention programmes.

First author Sport Age

(years)

Sex Injury definition Prevention programme Injuries in th

control grou

Content Frequency/

duration

Emery83 (CRCT) Basketball 12 18 m f All injuries

occurring during

basketball that

required medical

attention and/or

caused a player to

be removed from

that current

session and/or miss

a subsequent

session

Sport-specific

balance training

warm-up for practice

sessions

5 min during one

basketball season

(5 times/week)

Acute-onset

injuries: 3.83

1000 player

hours

Home exercise

programme using a

wobble board

20 min (frequency

NR).

Emery85 (CRCT) Multiple 14 19 m f Any injury

occurring during a

sporting activity

that required

medical attention(i.e. visit to an

emergency

department or

physicians office,

chiropractic,

physiotherapy or

athletic therapy)

or resulted in the

loss of at least 1

day of sporting

activity, or both

A progressive,

home-based,

proprioceptive

balance-training

using a wobbleboard

Daily training for

6 weeks and then

weekly for

maintenance for

the rest of the6-month study

period

17%

participants

with injury

Heidt69 (RCT) Soccer 14 18 f An injury that

caused the athleteto miss a game or

a practice session

Cardiovascular

conditioning,plyometrics, sport

cord drills, strength

training and

flexibility exercises

to improve speed

and agility

7-week training

programmebefore the start

of the season (20

sessions)

33.7%

participantswith injury

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Table 1. Continued


(years)


control grou

Content Frequency/

duration

Hewett65 (CNRCT) Multiple

(soccer

basketball

volleyball)

14 18 f A serious knee

injury was defined

as a knee ligament

sprain or rupture

that caused the

player to seek care

by an athletic

trainer and that

led to at least 5

consecutive days of

lost time from

practice and

games

Neuromuscular

training programme,

incorporating

flexibility,

plyometrics and

weight training to

increase muscle

strength and

decrease landing

forces

6-week preseason

training sessions

that lasted 60

90 min a day, 3

days a week, on

alternating days;

1 season

follow-up

0.43 knee

injuries/1000

AE (untraine

females) 0.09

knee injuries

1000 AE (ma

athletes)

Junge86 (CNRCT) Soccer 14 19 m Any physical

complaint caused

by soccer that

lasted for more

than 2 weeks or

resulted in absence

from a subsequent

match or training

session

Improvement of

warm-up, regular

cooldown, taping of

unstable ankles,

adequate

rehabilitation,

application of the

11

two 1-year season

intervention (no

other details

indicated)

low-skill

group: 11.1/

1000 h

Malliou87 (CRCT) Soccer 15 18 NR An injury was

defined as any

mishap occurring

during scheduled

games or practices

causing an athlete

to miss a

subsequent game

or practice session

Proprioceptive

balance training

program, which

included

sport-specific

exercises on the

Biodex Stability

System, on the

mini-trampoline and

on the balance

boards

20-min balance

training twice a

week during the

competition

period

88 lower lim

injuries

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Mandelbaum80

(non-randomized

prospective cohort

study)

Soccer 14 18 f Non-contact ACL

tear was

confirmed by

history, physical

examination by a

physician and MRI

and/or

arthroscopic

procedure

Proprioceptive and

neuromuscular

programme,

including warm-up,

stretching,

strengthening,

plyometrics and

soccer-specific agility

drills

20-min warm-up

before each

athletic activity

during two

one-season

interventions

Season 1: 0.4

ACL injuries/

1000 AE;

Season 2: 0.5

ACL injuries/

1000 AE

McGuine84 (CRCT) Multiple

(soccer

basketball)

16 m f An ankle sprain

was defined as a

trauma that (i)

disrupted the

ligaments of the

ankle, (ii) occurred

during a

coach-directed

competition,

practice or

conditioning

session and (iii)caused the athlete

to miss the rest of

a practice or

competition or

miss the next

scheduled

coach-directed

practice or

competition

Balance exercises on

a flat surface or on a

board such as

single-leg stance

with eyes open and

closed; performing

functional sport

activities such as

throwing, catching

and dribbling on

one leg; maintaining

double-leg stancewhile rotating the

balance board

Progressive

five-phase

balance training

program; phases

1 4: five exercise

sessions/week for

4 weeks before

the start of the

season; in phase 5

(maintenance

phase), three

10-min sessions/week

1.87 ankle

sprains/1000

AEs

McHugh88

(prospective

cohort study)

Soccer 15 18 NR An inversion ankle

sprain was defined

as an ankle injury

with an inversion

mechanism

requiring the

player to miss at

least one game or

practice

Single-limb balance

training on a foam

stability pad

Balance training

was performed

for 5 min on each

leg, 5 days/week

for 4 weeks in

preseason and 2

times/week for 9

weeks during the

season

2.2 ankle

sprains/1000

exposures


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Table 1. Continued


(years)


control grou

Content Frequency/

duration

Olsen81 (CRCT) Handball 15 17 m f Any injury

occurring during a

scheduled match

or training session,

causing the player

to require medical

treatment or miss

part of the next

match or training

session

Exercises with the

ball, including the

use of the wobble

board and balance

mat to improve

running, cutting and

landing technique as

well as

neuromuscular

control, balance and

strength

During an

8-month season,

1520-min

programme at the

beginning of

every training

session for 15

consecutive

sessions and then

1/week during the

rest of the season

1.8 acute

injuires/1000

player hours

(0.6 in

training 10.3

in match)

Soligard23 (CRCT) Soccer 13 17 f An injury occurred

during scheduled

match or training

session, causing

the player to be

unable to fully

take part in the

next match or

training session

Application of 11 20-min

programme at all

training sessions

and prior to

matches for one

8-month season

4.8/1000 h

Wedderkopp90

(CRCT)

Handball 16 18 f Any injury

occurring during

scheduled games

or practices,

causing the player

to either miss the

next game,

practice session or

being unable to

participate

without

considerable

discomfort

Ankle disc practice

and two or more

functional strength

activities for all

major muscle groups

1015-min

programme at all

training sessions

for one 10-month

season

1.17/1000 h o

practice,

23.38/1000 h

of match

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Wedderkopp89

(CRCT)

Handball 14 16 f Any injury

occurring during

scheduled games

or practices,

causing the player

to either miss the

next game,

practice session or

being unable toparticipate

without

considerable

discomfort

Ankle disc practice

and two or more

functional strength

activities for all

major muscle groups

1015-min

programme at all

training sessions

for one 10-month

season

0.6/1000 h of

practice,

OR 4.8

(95% CI: 1.9

11.7); 6.9/

1000 h of

match

AE, athletes exposure; NR, not reported; m, male; f, female; CNRCT, cluster-non randomized controlled trial; CRCT, cluster randomized

controlled trial.

*Significantly different from the control group (P, 0.05).


009

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Table 2. Summary of studies reporting on unsuccessful active prevention programmes.

First

author

Sport Age

(years)

Sex Injury definition Prevention programme Injuries in

the control

groupContent Frequency/Duration

Emery83

(CRCT)

Basketball 1218 m f All injuries occurring

during basketball that

required medical

attention and/or

caused a player to be

removed from that

current session and/or

miss a subsequent

session

Sport-specific balance

training warm-up for

practice sessions

5 min during one

basketball season (5

times/week)

All injuries:

4.03/1000

player

hours

Home exercise

programme using a

wobble board

20 minutes (frequency

NR)

Junge86

(CNRCT)

Soccer 14 19 m Any physical complaint

caused by soccer that

lasted for more than 2weeks or resulted in

absence from a

subsequent match or

training session

Improvement of

warm-up, regular

cooldown, taping ofunstable ankles,

adequate

rehabilitation,

application of the 11

Two 1-year season

intervention

high-skill

group:

6.78/1000 h

Steffen82

(CRCT)

Soccer 13 17 f An injury was

registered if it caused

the player to be

unable to fully take

part in the next match

or training session

Application of the

11

During one soccer

season (8 months),

20-min warm-up

programme (including

5 min of jogging before

starting the exercises)

every training session

for 15 consecutive

sessions and thereafter1/week for the rest of

the season

3.7/1000 h

AE, athletes exposure; NR, not reported; m, male; f, female; CNRCT, cluster-non randomized controlled trial; CRCT, cluster randomized

controlled trial.

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009



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interventions at a disadvantage, since the quality of the execution (andthe compliancesee below) cannot be easily verified. Another factor toconsider is the possibility for variation and progression in the exerciseset, which will avoid ceiling effects, enhance motivation among trainersand athletes and favour compliance.81 Indeed, the 11-programme

applied by Steffen et al.82

in a group of young soccer players did notprovide the possibility for variation and progression, was characterizedby a low compliance and had no significant effect on injury incidence.Similarly, Junge et al.86 did not find significant improvements in injurystatistics with this prevention method in already skilled soccer players(cf. Table 2), only the low-skilled group had a decreased injury inci-dence (cf. Table 1). On the other hand, the revised 11 versionincluding additional exercises to provide variation and progression,plus a new set of structured running exercises, reduced the risk ofsevere injuries, overuse injuries and injuries overall in young femalesoccer players.37

Globally, there is a strong tendency of interventions with a high com-pliance to bring about significant reductions in injury inci-dence,37,65,80,81,84,88 whereas studies in which compliance to theprogramme was low showed only marginal effects.82,83 It should benoted here that a home exercise programme may be less motivatingand result in poorer compliance than a supervised and structured train-ing agenda followed in a group of peer athletes. Considering the factthat the young athletes behaviour can be easily influenced by theenvironment, the attitude of the trainers and probably also of theparents may be of particular importance here. The investigation of

Mandelbaum et al.80 had a team compliance of almost 100%, whichlead to an 88% reduction in ACL injuries in female soccer players.Similarly, in the study of Olsen et al.,81 87% of the participating clubsapplied the proposed intervention programme throughout the studyperiod, which yielded a 50% decrease in acute injuries in young hand-ball players. Hewett et al.65 found a 72% reduction in knee injuries infemale athletes from team sports after a specific 6-week preseasonpreparation. All the girls from the intervention group followed the pre-vention programme for 4 weeks, and 70% of them accomplished thefull training programme. McGuine and Keene84 reported a compliance

of 91%, which lead to a 38% reduction in ankle sprains in male andfemale high-school basketball and soccer players. In the study ofMcHugh et al.88 91% of the athletes followed the entire balance train-ing. The authors observed an overall reduction in injury incidence of77%. In contrast to the previous studies, Steffen et al.82 noted a lowtraining session compliance among young soccer players (52%),despite regular contacts with the coaches during the study period andencouragements to continue the intervention programme. Accordingly,




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the results did not reveal the expected training effects of reduced sportsinjury risk (cf. Table 2).

Given the previous findings, it appears that appropriate content andhigh compliance are critical, yet insufficient factors for a successfulintervention. Another important aspect seems to be the frequency and

duration of the prevention sessions, for which some fundamental differ-ences can be noted (cf. Tables 1 and 2). Some programmes with signifi-cant reductions in injury statistics have encompassed an initial highvolume phase of prevention exercises, i.e. 15 40 sessions of 1520 min, performed either daily or in every practice, followed by oneweekly session for maintenance.81,85 Another successful approach hasbeen to introduce a pre-season preparation programme of 1820 ses-sions over 67 weeks, with durations of up to 90 min.65,69 Finally, astrategy of continuous, moderate volume prevention training of 1020 min in each practice session (e.g. during warm-up) also yielded posi-tive results.37,80,89,90 From these results, it can be concluded that fre-quency and duration of preventive training sessions should guaranteecertain minimal criteria. All in all, the final choice will depend on prac-tical considerations of feasibility and acceptance by trainers andathletes.

Conclusion

Acute injuries and overuse syndromes in the young athlete deservespecific consideration. Detailed knowledge about injury incidence,

injury type and modifiable and non-modifiable risk factors makes itpossible to design pertinent prevention programmes. Their effectivenessdepends on a number of characteristics related to content, compliance,duration and frequency. Practical issues regarding implementation ofand adherence to these prevention exercises require special attention.The proposed programmes should be time-efficient for the trainers andmotivating for the athletes.

There seem to be no systematic analyses about the effectiveness ofinjury prevention programmes directed to the upper extremity, despitewell-described injury patterns. The latter are rather sport-specific and

concern, e.g. the young overhead athlete. The reasons why this areamay have raised less interest in the field of sports medicine are notclear. Attention should be drawn here to interventions aiming atdecreasing muscle dysbalances and restoring appropriate ranges ofmotion. The modalities and efficiency of such training programmes areyet to be investigated by long-term prospective follow-ups.

Finally, it is important to take into account the education of trainersand coaches. Indeed, few coaches consider sports injuries as an issue

A. Frisch et al.



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they can impact on.37 It is also regrettable that injury prevention seemsto have a rather low priority and has been cited by some trainers as areason for non-participation in injury prevention studies.37 This indi-cates the necessity to include the topic of injury prevention in the curri-cula of trainers and coaches. Furthermore, information and education

of the parents and the young athletes themselves should be reinforced.Only an uninjured athlete is able to perform at his/her best.

Funding

The present work has been financially supported by the ministerialdepartment of sports of the Grand-Duchy of Luxembourg.

References1 Haskell WL, Lee IM, Pate RR et al. (2007) Physical activity and public health: updated rec-

ommendation for adults from the American College of Sports Medicine and the AmericanHeart Association. Circulation, 116, 10811093.

2 Okely AD, Booth ML, Patterson JW (2001) Relationship of physical activity to fundamentalmovement skills among adolescents. Med Sci Sports Exerc, 33, 18991904.

3 Wong P, Chia MY, Tsou IY et al. (2008) Effects of a 12-week exercise training programmeon aerobic fitness, body composition, blood lipids and C-reactive protein in adolescents withobesity. Ann Acad Med Singapore, 37, 286288.

4 Kohrt WM, Bloomfield SA, Little KD, Nelson ME, Yingling VR (2004) Physical activity andbone healthACSM position stand. Med Sci Sports Exerc, 36, 19851996.

5 Caine D, Caine C, Maffulli N (2006) Incidence and distribution of pediatric sport-relatedinjuries. Clin J Sport Med, 16, 500513.

6 Saxon L, Finch C, Bass S (1999) Sports participation, sports injuries and osteoarthritis: impli-cations for prevention. Sports Med, 28, 123135.

7 Cumps E, Verhagen E, Annemans L, Meeusen R (2008) Injury rate and socioeconomic costsresulting from sports injuries in Flanders: data derived from sports insurance statistics 2003.Br J Sports Med, 42, 767772.

8 de Loes M, Dahlstedt LJ, Thomee R (2000) A 7-year study on risks and costs of knee injuriesin male and female youth participants in 12 sports. Scand J Med Sci Sports, 10, 9097.

9 Gianotti SM, Marshall SW, Hume PA, Bunt L (2008) Incidence of anterior cruciate ligamentinjury and other knee ligament injuries: a national population-based study. J Sci Med Sport,in press.

10 Verhagen EA, van Tulder M, van der Beek AJ, Bouter LM, van Mechelen W (2005) An econ-omic evaluation of a proprioceptive balance board training programme for the prevention ofankle sprains in volleyball. Br J Sports Med, 39, 111115.

11 van Mechelen W, Hlobil H, Kemper HC (1992) Incidence, severity, aetiology and preventionof sports injuries. A review of concepts. Sports Med, 14, 8299.

12 Caine D, Knutzen K, Howe W et al. (2003) A three-year epidemiological study of injuriesaffecting young female gymnasts. Phys Ther Sport, 4, 1023.

13 Dixon M, Fricker P (1993) Injuries to elite gymnasts over 10 yr. Med Sci Sports Exerc, 25,13221329.

14 Dubravcic-Simunjak S, Pecina M, Kuipers H, Moran J, Haspl M (2003) The incidence ofinjuries in elite junior figure skaters. Am J Sports Med, 31, 511517.

15 Emery CA, Meeuwisse WH (2006) Injury rates, risk factors, and mechanisms of injury inminor hockey. Am J Sports Med, 34, 19601969.




24/27

16 Hickey GJ, Fricker PA, McDonald WA (1997) Injuries of young elite female basketballplayers over a six-year period. Clin J Sport Med, 7, 252256.

17 Kakavelakis KN, Vlazakis S, Vlahakis I, Charissis G (2003) Soccer injuries in childhood.Scand J Med Sci Sports, 13, 175178.

18 Kibler WB, Safran MR (2000) Musculoskeletal injuries in the young tennis player. ClinSports Med, 19, 781792.

19 Kolt GS, Kirkby RJ (1999) Epidemiology of injury in elite and subelite female gymnasts: a

comparison of retrospective and prospective findings. Br J Sports Med, 33, 312318.20 Le Gall F, Carling C, Reilly T (2008) Injuries in young elite female soccer players: an

8-season prospective study. Am J Sports Med, 36, 276 284.21 Olsen OE, Myklebust G, Engebretsen L, Bahr R (2006) Injury pattern in youth team hand-

ball: a comparison of two prospective registration methods. Scand J Med Sci Sports, 16,426432.

22 Soderman K, Adolphson J, Lorentzon R, Alfredson H (2001) Injuries in adolescent femaleplayers in European football: a prospective study over one outdoor soccer season. Scand JMed Sci Sports, 11, 299304.

23 Verhagen EA, Van der Beek AJ, Bouter LM, Bahr RM, Van Mechelen W (2004) A oneseason prospective cohort study of volleyball injuries. Br J Sports Med, 38, 477481.

24 Wedderkopp N, Kaltoft M, Lundgaard B, Rosendahl M, Froberg K (1997) Injuries in youngfemale players in European team handball. Scand J Med Sci Sports, 7, 342347.

25 Bailey DA, Wedge JH, McCulloch RG, Martin AD, Bernhardson SC (1989) Epidemiology offractures of the distal end of the radius in children as associated with growth. J Bone JointSurg Am, 71, 12251231.

26 Deitch J, Mehlman CT, Foad SL, Obbehat A, Mallory M (2003) Traumatic anterior shoulderdislocation in adolescents. Am J Sports Med, 31, 758763.

27 Kujala UM, Kvist M, Heinonen O (1985) Osgood Schlatters disease in adolescent athletes.Retrospective study of incidence and duration. Am J Sports Med, 13, 236241.

28 Sugimori H, Odajima T, Yamaguchi K (2008) Epidemiological study of fractures in Japanesechildren and adolescents. Clin Calcium, 18, 844850.

29 Caine D, Maffulli N, Caine C (2008) Epidemiology of injury in child and adolescent sports:injury rates, risk factors, and prevention. Clin Sports Med, 27, 19 50, vii.

30 Emery CA (2003) Risk factors for injury in child and adolescent sport: a systematic review ofthe literature. Clin J Sport Med, 13, 256268.

31 McGuine T (2006) Sports injuries in high school athletes: a review of injury-risk and injury-prevention research. Clin J Sport Med, 16, 488499.

32 Brooks JH, Fuller CW (2006) The influence of methodological issues on the results and con-clusions from epidemiological studies of sports injuries: illustrative examples. Sports Med, 36,459472.

33 Finch CF (1997) An overview of some definitional issues for sports injury surveillance. SportsMed, 24, 157163.

34 Hawkins RD, Fuller CW (1999) A prospective epidemiological study of injuries in fourEnglish professional football clubs. Br J Sports Med, 33, 196203.

35 Fuller CW, Ekstrand J, Junge A et al. (2006) Consensus statement on injury definitions anddata collection procedures in studies of football (soccer) injuries. Clin J Sport Med, 16,97106.

36 Fuller CW, Molloy MG, Bagate C et al. (2007) Consensus statement on injury definitionsand data collection procedures for studies of injuries in rugby union. Clin J Sport Med, 17,

177181.37 Soligard T, Myklebust G, Steffen K et al. (2008) Comprehensive warm-up programme to

prevent injuries in young female footballers: cluster randomised controlled trial. Br Med J.38 Hewett TE, Myer GD, Ford KR et al. (2005) Biomechanical measures of neuromuscular

control and valgus loading of the knee predict anterior cruciate ligament injury risk in femaleathletes: a prospective study. Am J Sports Med, 33, 492501.

39 Emery CA, Meeuwisse WH, Hartmann SE (2005) Evaluation of risk factors for injury in ado-lescent soccer: implementation and validation of an injury surveillance system. Am J SportsMed, 33, 18821891.

A. Frisch et al.



25/27

40 McGuine TA, Greene JJ, Best T, Leverson G (2000) Balance as a predictor of ankle injuriesin high school basketball players. Clin J Sport Med, 10, 239244.

41 Messina DF, Farney WC, DeLee JC (1999) The incidence of injury in Texas high school bas-ketball. A prospective study among male and female athletes. Am J Sports Med, 27,294299.

42 Smith R, Damodaran AK, Swaminathan S, Campbell R, Barnsley L (2005) Hypermobilityand sports injuries in junior netball players. Br J Sports Med, 39, 628631.

43 Belechri M, Petridou E, Kedikoglou S, Trichopoulos D (2001) Sports injuries among childrenin six European union countries. Eur J Epidemiol, 17, 10051012.

44 Kucera KL, Marshall SW, Kirkendall DT, Marchak PM, Garrett WE Jr (2005) Injury historyas a risk factor for incident injury in youth soccer. Br J Sports Med, 39, 462.

45 Maffulli N, Magra M (2006) The younger athlete. In Brukner P, Khan K (eds) Clinical SportsMedicine. North Ryde: McGraw-Hill Australia, 727748.

46 Junge A, Chomiak J, Dvorak J (2000) Incidence of football injuries in youth players. Am JSports Med, 28, S-47S-50.

47 Krivickas LS (1997) Anatomical factors associated with overuse sports injuries. Sports Med,24, 132146.

48 Cassas KJ, Cassettari-Wayhs A (2006) Childhood and adolescent sports-related overuse inju-ries. Am Fam Physician, 73, 10141022.

49 Bylak J, Hutchinson MR (1998) Common sports injuries in young tennis players. Sports

Med, 26, 119132.50 Adirim TA, Cheng TL (2003) Overview of injuries in the young athlete. Sports Med, 33,

7581.51 Hogan KA, Gross RH (2003) Overuse injuries in pediatric athletes. Orthop Clin North Am,

34, 405415.52 Price RJ, Hawkins RD, Hulse MA, Hodson A (2004) The Football Association medical

research programme: an audit of injuries in academy youth football. Br J Sports Med, 38,466471.

53 Gillquist J, Messner K (1999) Anterior cruciate ligament reconstruction and the long-termincidence of gonarthrosis. Sports Med, 27, 143156.

54 Lohmander LS, Englund PM, Dahl LL, Roos EM (2007) The long-term consequence ofanterior cruciate ligament and meniscus injuries: osteoarthritis. Am J Sports Med, 35,17561769.

55 Myklebust G, Engebretsen L, Braekken IH, Skjolberg A, Olsen OE, Bahr R (2003)Prevention of anterior cruciate ligament injuries in female team handball players: a prospec-tive intervention study over three seasons. Clin J Sport Med, 13, 7178.

56 Moller E, Weidenhielm L, Werner S (2009) Outcome and knee-related quality of life afteranterior cruciate ligament reconstruction: a long-term follow-up. Knee Surg Sports TraumatolArthrosc, 17, 786794.

57 Moksnes H, Engebretsen L, Risberg MA (2008) Performance-based functional outcome forchildren 12 years or younger following anterior cruciate ligament injury: a two to nine-yearfollow-up study. Knee Surg Sports Traumatol Arthrosc, 16, 214223.

58 Anandacoomarasamy A, Barnsley L (2005) Long term outcomes of inversion ankle injuries.Br J Sports Med, 39, e14; discussion e14.

59 Kaikkonen A, Lehtonen H, Kannus P, Jarvinen M (1999) Long-term functional outcomeafter surgery of chronic ankle instability. A 5-year follow-up study of the modified Evans pro-cedure. Scand J Med Sci Sports, 9, 239244.

60 Owens BD, DeBerardino TM, Nelson BJ et al. (2009) Long-term follow-up of acute arthro-scopic Bankart repair for initial anterior shoulder dislocations in young athletes. Am J SportsMed, 37, 669673.

61 Robinson CM, Howes J, Murdoch H, Will E, Graham C (2006) Functional outcome and riskof recurrent instability after primary traumatic anterior shoulder dislocation in youngpatients. J Bone Joint Surg Am, 88, 23262336.

62 Tyler TF, McHugh MP, Mirabella MR, Mullaney MJ, Nicholas SJ (2006) Risk factors fornoncontact ankle sprains in high school football players: the role of previous ankle sprainsand body mass index. Am J Sports Med, 34, 471475.




26/27

63 McHugh MP, Tyler TF, Tetro DT, Mullaney MJ, Nicholas SJ (2006) Risk factors for noncon-tact ankle sprains in high school athletes: the role of hip strength and balance ability. Am JSports Med, 34, 464470.

64 Maffulli N, Caine D (2005) The Epidemiology of childrens team sports injuries. Med SportSci, 49, 18.

65 Hewett TE, Lindenfeld TN, Riccobene JV, Noyes FR (1999) The effect of neuromusculartraining on the incidence of knee injury in female athletes. A prospective study. Am J Sports

Med, 27, 699706.66 Frisch A, Seil R, Urhausen A, Croisier JL, Lair ML, Theisen D (2008) Analysis of sex-specific

injury patterns and risk factors in young high-level athletes. Scand J Med Sci Sports, in press.67 Jones D, Louw Q, Grimmer K (2000) Recreational and sporting injury to the adolescent

knee and ankle: prevalence and causes. Aust J Physiother, 46, 179188.68 Myer GD, Ford KR, Paterno MV, Nick TG, Hewett TE (2008) The effects of generalized

joint laxity on risk of anterior cruciate ligament injury in young female athletes. Am J SportsMed, 36, 10731080.

69 Heidt RS Jr, Sweeterman LM, Carlonas RL, Traub JA, Tekulve FX (2000) Avoidance ofsoccer injuries with preseason conditioning. Am J Sports Med, 28, 659662.

70 Woods K, Bishop P, Jones E (2007) Warm-up and stretching in the prevention of muscularinjury. Sports Med, 37, 10891099.

71 Willems TM, Witvrouw E, Delbaere K, Mahieu N, De Bourdeaudhuij I, De Clercq D (2005)

Intrinsic risk factors for inversion ankle sprains in male subjects: a prospective study. Am JSports Med, 33, 415423.

72 Steffen K, Pensgaard AM, Bahr R (2008) Self-reported psychological characteristics as riskfactors for injuries in female youth football. Scand J Med Sci Sports, in press.

73 Gunnoe AJ, Horodyski M, Tennant LK, Murphey M (2001) The effect of life events on inci-dence of injury in high school football players. J Athl Train, 36, 150155.

74 Junge A (2000) The influence of psychological factors on sports injuries. Review of the litera-ture. Am J Sports Med, 28, S10S15.

75 Kolt G, Kirkby R (1996) Injury in Australian female competitive gymnasts: a psychologicalperspective. Aust J Physiother, 42, 121126.

76 Williams J, Anderson M (1998) Psychosocial antecedents of sport injury: review and critiqueof the stress and injury model. J Appl Sport Psychol, 10, 5 25.

77 Spinas E, Savasta A (2007) Prevention of traumatic dental lesions: cognitive research on therole of mouthguards during sport activities in paediatric age. Eur J Paediatr Dent, 8,193198.

78 Wesson DE, Stephens D, Lam K, Parsons D, Spence L, Parkin PC (2008) Trends in pediatricand adult bicycling deaths before and after passage of a bicycle helmet law. Pediatrics, 122,605610.

79 Dvorak J, Junge A (2005) Football Medicine Manual. Zurich: F-MARC, 81 93.80 Mandelbaum BR, Silvers HJ, Watanabe DS et al. (2005) Effectiveness of a neuromuscular

and proprioceptive training program in preventing anterior cruciate ligament injuries infemale athletes: 2-year follow-up. Am J Sports Med, 33, 10031010.

81 Olsen OE, Myklebust G, Engebretsen L, Holme I, Bahr R (2005) Exercises to prevent lowerlimb injuries in youth sports: cluster randomised controlled trial. Br Med J, 330, 449.

82 Steffen K, Myklebust G, Olsen OE, Holme I, Bahr R (2008) Preventing injuries in femaleyouth footballa cluster-randomized controlled trial. Scand J Med Sci Sports, in press.

83 Emery CA, Rose MS, McAllister JR, Meeuwisse WH (2007) A prevention strategy to reduce

the incidence of injury in high school basketball: a cluster randomized controlled trial. Clin JSport Med, 17, 1724.

84 McGuine TA, Keene JS (2006) The effect of a balance training program on the risk of anklesprains in high school athletes. Am J Sports Med, 34, 11031111.

85 Emery CA, Cassidy JD, Klassen TP, Rosychuk RJ, Rowe BH (2005) Effectiveness of a home-based balance-training program in reducing sports-related injuries among healthy adolescents:a cluster randomized controlled trial. CMAJ, 172, 749754.

86 Junge A, Rosch D, Peterson L, Graf-Baumann T, Dvorak J (2002) Prevention of soccer inju-ries: a prospective intervention study in youth amateur players. Am J Sports Med, 30,652659.

A. Frisch et al.



27/27

87 Malliou P, Gioftsidou A, Pafis G, Beneka A, Godolias G (2004) Proprioceptive training(balance exercises) reduces lower extremity injuries in young soccer players. J BackMusculoskeletal Rehabil, 17, 101104.

88 McHugh MP, Tyler TF, Mirabella MR, Mullaney MJ, Nicholas SJ (2007) The effectivenessof a balance training intervention in reducing the incidence of noncontact ankle sprains inhigh school football players. Am J Sports Med, 35, 12891294.

89 Wedderkopp N, Kaltoft M, Holm R, Froberg K (2003) Comparison of two intervention pro-

grammes in young female players in European handballwith and without ankle disc. ScandJ Med Sci Sports, 13, 371375.

90 Wedderkopp N, Kaltoft M, Lundgaard B, Rosendahl M, Froberg K (1999) Prevention ofinjuries in young female players in European team handball. A prospective interventionstudy. Scand J Med Sci Sports, 9, 4147.


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