Injuries during physical activity in school children

Injuries during physical activity in school children

Gunilla Sundblad1, Tonu Saartok

1,2, Lars-Magnus Engstrom

3, Per Renstrom

1

1Department of Surgical Sciences, Section of Sports Medicine, Karolinska Institutet, Stockholm, Sweden, 2Department ofOrthopedics, Visby Hospital, Visby, Sweden, 3Stockholm Institute of Education, Stockholm, SwedenCorresponding author: Gunilla Sundblad, Department of Surgical Sciences, Section of Sports Medicine, Karolinska Institutet,SE-171 76 Stockholm, Sweden. Tel: 146 705 858 586, Fax: 146 88 59 144, E-mail: [email protected]

Accepted for publication 22 May 2004

During the spring of 2001, 1975 children, from grades 3, 6and 9 participated in a nationwide, multidisciplinary collab-oration study. The students came from randomly selectedclasses throughout Sweden, representing different geograph-ical and socio-economic areas. The aim of this study was tocollect and evaluate self-reported injuries and associatedfactors during various physical activities as recalled retro-spectively for 3 months by the students.

Every sixth student (n5 299 or 16%) reported 306injuries. Twice as many girls than boys were injured duringphysical education class. Ninth-grade students reportedrelatively more injuries during organized sports than during

physical education class and leisure activities. There were noage or gender differences in incidence rate during leisureactivities.Most injuries were minor, as 70% were back in physical

activity within a week. Half of the students (50%) reportedthat they previously had injured the same body part.Primary care of the injured student was, with the excep-

tion of a family member, most often carried out by thephysical education teacher or coach, which accentuates theimportance of continuous sports medicine first aid educationfor this group.

While there is a popular perception that children andadolescents in the industrial world are becoming lessphysically active and are adopting a sedentary life-style in front of computers and television screens,physical activity and sport remain a preferred past-time recreation for school children. In a Germanstudy, 84% of the boys and 60% of the girls, age 11–15years (Kelm et al., 2001) and in a Swiss study 65% ofthe boys and 40% of the girls, age 12 years, reportedsports club participation (Michaud et al., 2001).Most researchers (Ekblom & Astrand, 2000;

Landry, 2000; Bernhardt, 2001; Adirim & Cheng,2003) agree that physical activity during sport andrecreational play, if adapted and conducted on theterms of the child, is beneficial physiologically, med-ically and psychologically. It increases the child’sphysical capacity and also improves their balance,coordination and motor skills, of which the latter isconsidered a lifelong investment. Through a confi-dent and encouraging environment the child alsolearns social skills, self-discipline and develops self-esteem (Landry, 2000).Inevitably accidents and injuries do occur during

physical activity. These injuries not only cause thechildren unnecessary suffering, pain and risk for

future complications, but can also constitute a sub-stantial direct and indirect cost to society (Sorensenet al., 1998). In addition these injuries may also affecttheir attitude towards physical activity in the future(Kelm et al., 2001; Flynn et al., 2002).Children and adolescents are at greater risk to

sustain sport injuries than adults because of their notfully developed coordination, longer reaction timeand less maturity in risk assessment (Wiese-Bjornstal& Shaffer, 1999). Furthermore, there are anatomicalas well as biomechanical differences attributable tothe growing skeleton and tissue, making childrenand adolescents susceptible to unique injuries andpatterns thereof (Guy & Micheli, 1999; Maffulli &Bruns, 2000). During growth spurt, with periodsof ‘‘disproportionate growth’’ (Bernhardt, 2001)adolescents usually loose some of their flexibility,coordination and endurance, which can increase therisk of injury (Hawkins & Metheny, 2001; Adirim &Cheng, 2003). In this phase the physical maturation,i.e. the biological age, is more important than thechronological. The injury pattern may further changeduring adolescence because of varying and increasedexposure to new activities and risks.In the US, there are approximately three million

injuries each year among children and adolescentsparticipating in sports activities (Hergenroeder, 1998;Bernhardt, 2001). A comparative study performed in

In collaboration with University College of Physical Education andSports, Stockholm, Sweden.

Scand J Med Sci Sports 2005: 15: 313–323 COPYRIGHT & BLACKWELL MUNKSGAARD 2004

Printed in Denmark .All rights reservedDOI: 10.1111/j.1600-0838.2004.00419.x

313

England showed a 70% increase in the prevalence ofinjuries between 1983 and 1998 (Jones et al., 2001).The authors explained the increase being becauseof added sport participation and a wider range ofavailable sports, even when considering populationchanges, data recording and other methodologicaldiscrepancies.In Sweden, with a population of nearly nine

million, about 50 000 children and adolescents (age9–15 years) sought medical attention during the year2001 for injuries that had occurred during physicalactivities, either at school, in organized sports club orduring leisure activities. These injuries account forhalf of the total numbers of injuries sustained withinthis age group (European Home and Leisure Acci-dent Surveillance System (EHLASS), The NationalBoard of Health and Wellfare, A. Karlsson, personalcommunication, 2003).The aim of the present study was to collect and

evaluate reported injuries and associated factors thatoccurred in Swedish school children during a 3-month recall period, at different ages (9, 12 and 15years at the onset of the year), for both genders, andduring various physical activities.

Material

The Swedish Bureau of Statistics conducted an independentrandom selection of schools with grades 3, 6 and 9 from allover Sweden to participate in our study. From the initialselection a stratified random selection was performed toreceive a comparable number of students representing thedifferent grades. A total of 58 schools were contacted witha letter outlining the study, which was followed up by atelephone call. A positive response was received from 48schools and those who declined (n5 10) did so because oflogistical constraints and other unfeasible circumstances (e.g.small countryside schools with only two to seven studentsmeeting the inclusive age criteria (n5 6), two schools that onlylisted students temporary for scholastic assistance and sup-port, and replacement of class teacher (n5 2)).

Parents or guardians of the students received written infor-mation and they returned a letter of informed consent beforethe study commenced. The identity of the students was codedto ensure anonymity.

The study was approved by the Ethical committee at theKarolinska Institutet, Stockholm (ref. no. 00-416).

A total of 1975 students from 48 schools, covering bothrural and urban areas, participated in at least one part of thestudy (see Fig. 1). They represented less than 1% (0.5% ingrade 3, 0.6% in grade 6% and 0.6% in grade 9) of all Swedishstudents in these respective grades (National Agency forEducation 2001, personal communication).

Method

The students, divided into groups by gender, answered both asports medicine and a life-style questionnaire, which includedquestions covering physical activity, demographic character-istics and socio-economic information. Anthropometric datawas recorded and the students performed medical, physiolo-

gical and applied motor ability tests. Results from the variousparts of this multidisciplinary study are under publicationseparately.

As part of the sports medicine tests, 1908 students (grade 3:255 girls and 305 boys; grade 6: 347 girls and 352 boys; grade9: 329 girls and 320 boys) anonymously completed undersupervision a questionnaire that was specially designed for thisstudy. The dropout rate for the sport medicine questionnaire(n5 67, 3%) was caused by incidental disease, absence andtechnical reasons.

The questionnaire consisted of five parts addressing thestudents’ (I) medical background, (II) perceived health, (III)injuries, (IV) eating habits, (V) alcohol, tobacco and drugusage. This last section (part V) was not included for the third-grade children but the questionnaire had otherwise the sametenor for the different grades. This article will present anddiscuss results from the part of the questionnaire that focusedon injuries.

The replies of the sports medicine questionnaire were as-signed binary scores (true5 1, false5 0), open or Likert type.According to Morrow et al. (2000) the validity of a ques-tionnaire can be secured through the cooperation withexperts in the area, performing pilot testing and assuringanonymity of the respondents. The present questionnairewas constructed in collaboration with a pediatrician andorthopedic surgeons trained in sports medicine. The surveys,at all stages coded for anonymity, were first pre-tested

Fig. 1. Location of participating schools throughout Sweden.

Sundblad et al.

314

by children of the corresponding age groups, and thereafter ina pilot study in November 2000 with 103 students from grades3, 6 and 9.

Reliability test

A reliability test, a 1-week test–retest procedure of the ques-tionnaire, was conducted with 38 school children in March2002. Eight students reported that an injury had occurredduring the recall period, a time period equivalent to the basestudy. One student failed to complete the questionnaire at thesecond occasion. The other seven students gave an identicalanswer on 99% of the 54 questions/items given. The reliabilitycoefficient value, using k, was not used in this section of thequestionnaire because of the low number of respondents.

Recall period

The students were asked whether they had sustained an injurybecause of physical activity at school or in their leisuretime ‘‘since the onset of the spring term’’, i.e. early Januaryuntil the testing period, in March/April. Thus the recall periodfor the students was 10–14 weeks.

Definition of injury

In the questionnaire, an injury was defined as a traumaticincident, resulting in medical attention/care by a school nurse,doctor or hospital. On the test day, the definition was furtherextended and explained verbally to the students, as an incidentduring physical activity at school or during their leisure timethat made them interrupt their activity and seek medicalattention by an adult, such as a physical education teacher,trainer, parent, school nurse, doctor and/or dentist.

Upon request, the students were assisted in their interpreta-tion and reading of the questionnaire. If an injury hadoccurred during the assigned recall period the incidence wasdiscussed with the test leader (G. S.) or physical educationteachers, assistants and/or parents who had accompanied thestudents.

Statistics

The questionnaires were converted into a database using theStatistical Package for the Social Sciences (SPSS 11.0, Chi-cago, IL, USA) computer software. For quality control, allquestionnaires were reread and checked for accuracy com-pared with the database.

Descriptive statistics, with frequencies measured for categor-ical variables, were used, and w2 was used for examining groupdifferences with statistical significance level set at Po0.05.

Results

During the recall period, 299 school students (16%)reported 306 injuries. There were no significant ageor gender differences in total amount of injuries. Thedistribution of injuries within the different settings isshown in Table 1.

Setting at injury

One-fourth of the injuries (25%) recalled in thisstudy had occurred during physical education class.The school students in our survey have physicaleducation lessons on average between 87 (grade 3)and 99 (grade 9)min a week. With an average of90min for 12 weeks an equation shows 2.2 injuredstudents per 1000 physical education hours. Almosttwice as many girls (n5 50) than boys (n5 27)(P5 0.004) were injured in this setting. The activityat the time of injury in physical education class isshown in Table 2.More girls than boys (26% vs. 15% in the whole

study group) noted in the medical background part(I) of the questionnaire that they had an impairedvision corrected with glasses or contact lenses. Sixty-seven percent of the girls and 58% of the boysreported that they did not always use their glassesor lenses while active with sports. Twice as manywith an impaired vision reported in our survey thatthey had been injured during physical education class(P5 0.009).Nearly one-fifth of the injuries (19%) had occur-

red while active within organized sports, practices(n5 41) as well as competition (n5 19). Whereasthere was no difference between the age groups re-garding injured during competition, a significantlyhigher proportion (68%) of the injured in organizedpractices were ninth-grade students (Po0.001 for agedifference). For distribution of injuries within sportsand information of sports club membership seeTable 3.Most injuries reported in our study occurred

during unorganized activities at leisure time and

Table 1. Injuries in different settings. N 5 306

Grade 3 Grade 6 Grade 9 Total (%)a

Girls Boys Girls Boys Girls Boys

Physical education 8 7 19 9 23 11 77 (25)Break 6 11 11 13 2 5 48 (16)Travel (back/forth to school) 1 3 2 0 3 0 9 (3)Leisure time 17 16 15 14 13 12 87 (29)Organized sports club/practice 1 3 5 4 12 16 41 (13)Organized sports club/competition 0 1 4 7 3 4 19 (6)Unknown 2 2 5 5 7 4 25 (8)Total (%) 35 (11) 43 (14) 61 (20) 52 (17) 63 (21) 52 (17) 306 (100)

aTwo hundred and ninety-nine students reported injuries in 306 settings.

Injuries during physical activity

315

Table 2. Activity when injured during physical education class. N 5 73b

Activity Grade 3 Grade 6 Grade 9 Total (%)


Apparatus 3 3 0 0 2 3 11 (15.1)Ball games 1 2 6 2 13 2 26 (35.6)Gymnastics 1 0 5 4 3 0 13 (17.8)Playtime 1 0 1 0 2 2 6 (8.2)Track and field 1 0 3 1 1 1 7 (9.6)Othera 0 2 3 3 0 2 10 (13.7)Total (%)b 7 (9.6) 7 (9.6) 18 (24.7) 10 (13.7) 21 (28.8) 10 (13.7) 73 (100)b

aSkiing, ice-skating, etc.bFour girls did not answer this question.

Table 3. Members in organized sports club and injuries within the sports

No. of members in organized sports club Injured during participation in organized sports Injured/100participants

Grade 3 Grade 6 Grade 9 Total (%) Grade 3 Grade 6 Grade 9 Total

BadmintonGirls 0 7 5 57Boys 1 5 3 43 None NoneTotal (%) 5 57 38

BasketGirls 6 15 13 81 0 1 3 4Boys 0 4 4 19 0 0 2 2 6/42 5 14%Total (%) 14 45 41 0 1 5

BowlingGirls 3 4 3 56Boys 3 3 2 44 None NoneTotal (%) 33 39 28

DanceGirls 33 41 46 95 0 0 1 1 1/126 5 0.8%Boys 1 2 3 5 0 0 0 0Total (%) 27 34 39 0 0 1

FloorballGirls 5 8 16 18 0 0 2 2Boys 32 58 46 82 0 1 0 1 3/165 5 1.8%Total (%) 22 40 38 0 1 2

GolfGirls 1 3 3 19Boys 6 7 16 81 None NoneTotal (%) 19 28 53

GymnasticsGirls 0 17 39 95 0 0 1 1Boys 0 0 3 5 0 0 1 1 2/59 5 3.4%Total (%) 0 29 71 0 0 2

HandballGirls 10 23 10 49 0 3 1 4Boys 11 20 13 51 0 2 0 2 6/87 5 7%Total (%) 24 50 26 0 5 1

Horse ridingGirls 52 44 37 94 0 0 2 2Boys 7 0 1 6 0 0 0 0 2/141 5 1.4%Total (%) 42 31 27 0 0 2

Ice-hockeyGirls 1 1 0 2 0 0 0 0Boys 33 44 37 98 1 2 6 9 9/116 5 9%Total (%) 33 44 23 1 2 6

Marshall artsGirls 3 2 7 28 0 0 0 0 4/43 5 9%Boys 14 8 9 72 0 0 4 4Total (%) 40 23 37 0 0 4

Sundblad et al.

316

especially for the third-grade children (P5 0.007,compared with the other two grades) with a totalof 87 students (or 29% of the injured population)involved. The injured students represented all esti-mated activity levels and their injuries reflected theadherent activities of winter months with manyskiing, snow boarding and skating sports (23% ofthe leisure time activities) included. The schoolchildren in our study answered several questionscovering their physical activities, as well as theintensity and frequency thereof. An activity indexwas constructed based on reported information fromphysical activity habits during physical educationclass, school breaks, and sports club and/or inunorganized physical activities as well as bicycling/walking to school and friends or to other activities in

the afternoon (Engstrom, 2004, unpublished). Thevalidity of the score was tested against the studentsresult from the submaximum bicycle test, which waspart of the physiological tests in this multidisciplin-ary study. No significant age or gender differenceswere present in total prevalence, but girls wereinjured during horse riding and skating, and boysdominated in hockey and snowboard. Most injuries,however, occurred during running and free playtime(27%). The activities at the time of injury duringleisure time are shown in Table 4 (including schoolbreaks and going back and forth to school).The majority of the injured students (n5 178, 60%

of the injured population) were injured for more thana month prior to the questionnaire administrationdate, about one-fourth (n5 78, 26%) had occurred

Table 3. (continued)

No. of members in organized sports club Injured during participation in organized sports Injured/100participants

Grade 3 Grade 6 Grade 9 Total (%) Grade 3 Grade 6 Grade 9 Total

Motor-crossGirls 0 0 0 0Boys 4 5 1 NoneTotal (%) 40 50 10

OrienteeringGirls 1 0 1 33Boys 1 1 2 67 NoneTotal (%) 33 17 50

SkiingGirls 8 9 1 51 0 1 0 1 1/35 5 3%Boys 10 5 2 49 0 0 0 0Total (%) 51 40 9 0 1 0

Rifle-shootingGirls 0 2 0 11Boys 8 7 1 89 NoneTotal (%) 44 50 6

SoccerGirls 44 78 16 28 1 4 3 8Boys 127 149 82 72 2 6 6 14 22/496 5 4%Total (%) 34 46 20 3 10 9

SwimmingGirls 12 16 17 74 0 0 0 0Boys 6 6 4 26 1 0 0 1 1/61 5 1.6%Total (%) 30 36 34 1 0 0

Table tennisGirls 2 4 2 18Boys 14 21 1 82 NoneTotal (%) 36 57 7

TennisGirls 11 3 6 47 0 0 1 1Boys 13 5 5 53 0 0 0 0 1/43 5 2%Total (%) 56 19 25 0 0 1

Track and fieldGirls 7 9 5 62 NoneBoys 2 8 3 38 3/34 5 9%Total (%) 26 50 24

VolleyballGirls 0 3 0 60 0 0 1 1Boys 1 0 1 40 0 0 0 0 1/5 5 20%Total (%) 20 60 60 0 0 1


317

within 1 week to a month, and 37 students (12%)were injured less than a week prior to the day of thesurvey. Six of the injured students (2%) failed toanswer this question.

Location and type of injury

The most frequently reported injured body part wasthe lower extremities (47%) followed by the upperextremities (27%). See Fig. 2 for location of injuries.The youngest school students (grade 3) noted moredental injuries (P5 0.001) as well as other injuries inthe head and neck area (P5 0.004) than their olderschoolmates. Every other injured student (50%)reported that they previously had injured the samebody part. Among students with a leg and footinjury, 58% had had a recurrent injury at the samelocation.Strains and sprains were the most common type of

injury reported by 49% of the injured population,followed by contusions and wounds (both 14%).The distribution of more serious injuries, i.e. dis-

locations, fractures, and concussions were 4%, 5%,and 5%, respectively. Seventeen percent (n5 320,14% girls and 20% boys, P5 0.001 for genderdifference) of all students in the study reported that

they have had an injury that required a cast treat-ment earlier in life and over two-thirds (70%) ofthese injuries had been located in the arm or hand.The 3 months incidence of strains and sprains

increased with age (P5 0.008), as did dislocations(P5 0.003). There were no gender differences in typeof injury.

Mechanism of injury

More than half of the cases (53%) were caused by thestudent her/himself through falls or twisted move-ments. Collisions with another student, or beinghit by a loose object, occurred in 14% of thecases. Remaining injuries were associated with afixed object, transportation, fight or contact with ananimal (horse or dog).

Primary care

After their injury, most students (n5 98, 33%) werefirst attended by their parent(s) or another adultmember of the family. The physical educationteacher, class and/or athletic trainer cared for 26%(n5 78) of the incidences in all age groups. Primarycare by a physician or a physical therapist occurredin 17% (n5 51) of all cases, with an increase to 27%for the students in grade 9 (Po0.001). Twenty-fourpercent (n5 70) were cared for by the school nurse orothers, with a rise in visits by the third-grade students(n5 29, 38%) (P5 0.001). There were no significantgender differences in primary care.Immediately after the accident the most commonly

reported first aid given was compression (28%) andthereafter ice (14%).

Rehabilitation

One-fifth (20%) of the students in grade 9 recalledhaving visited a physical therapist or a certified

Table 4. Activity when injured during leisure time. N 5 123 (including school breakes and going back and forth to school)

Activity Grade 3 Grade 6 Grade 9 Total (%)


Ball games 3 6 4 7 1 3 24 (20)Bicycle 3 4 1 1 0 1 10 (8)Fighting 0 0 1 2 0 1 4 (3)Hockey/Bandy 0 3 0 5 1 0 9 (7)Horse riding 2 0 3 0 2 0 7 (6)Ice-skating 0 0 2 0 1 0 3 (2)Play time 8 9 6 3 6 2 34 (28)Skiiing 1 0 1 1 1 1 5 (4)Snowboard 0 0 0 1 2 4 7 (6)Snowracer/sledge 1 2 0 0 0 0 3 (2)Othera 3 2 5 2 2 3 17 (14)Total (%) 21 (17) 26 (21) 23 (19) 22 (18) 16 (13) 15 (12) 123 (100)

aSkateboard, knocked by a dog, transport, trampolin, rollerblades, etc.

Fig. 2. Location of injury.

Sundblad et al.

318

naprapath after their injury (8% of the students ingrade 3 and 14% in grade 6). Fourteen percent of thestudents (11% girls, 18% boys) with strains andsprains reported that they were rehabilitated profes-sionally after their injury. Every other student with adiagnosed dislocation (six out of 12) and every othergirl with a fracture (four out of eight) had receivedphysio-therapeutic treatment but none of the boys(n5 8) with a fracture reported this care. The numbersare, however small, 12 dislocations and 17 fractures.The rehabilitation of one fracture was unknown.Alternative physical activities and one-on-one

training during physical education class, were offeredto 5% of the injured in grade 3, 8% in grade 6 and30% in grade 9 (Po0.001, for the age difference).

Severity

After the injury, 70%, age and gender alike, couldreturn to physical activities at school within a week,their injury being classified as minor, according tothe abbreviated injury scale (AIS). A common clas-sification of severity, AIS (American Association forAutomotive Medicine, 1980) use three differentgrades, code 1 (return within a week), 2 (absencefor more than a week but less than a month) and 3(absence for more than a month), according to whenthe athlete could return to their activity. This classi-fication was used in other Swedish studies (Ekstrand,1982; Jacobsson et al., 1986; de Loes, 1990) and thuswe chose this standard in our study. One-fourth(26%) of the students had sustained a moderateinjury, i.e. they could return within a month. Theremaining 4% had not yet returned to physicalactivities after their injury. Less than 3% (n5 8) ofthe injured students stated that their injury hadresulted in them not being able to commence sportsin their leisure time. In two of the cases multipleinjuries were involved.Most students (93%) answered that they had not

or were not aware of if a claim had been put forwardto an insurance company after their injury. In 7%of the injured cases (mostly fractures, dislocations,facial traumas and multiple injuries) a report hadbeen filed according to the students.

Discussion

An unwanted side effect to physical activity inchildren and adolescents is, as our results show,injuries and residual morbidity, which therefore isan area of concern. In this large Swedish school studyevery sixth student (16%) reported an injury duringour 3-month recall period. There was a genderdifference in injuries reported during physical educa-tion class, an age difference during organized sportsbut no age or gender difference during leisure activ-ities (see Table 1).

Studies of sports injuries in school-age children aremostly based on medical records from hospitals andemergency units (Tursz & Crost, 1986; Sahlin, 1990;Sorensen et al., 1996; Brudvik, 2000; Jones et al.,2001; Kelm et al., 2001). Such records rarely includeinjuries managed by physical education teachers,athletic coaches, school nurses, dentists, parents orother adults caring for the child. These injuries,below the ‘‘tip-of-the-iceberg’’ (Last, 1963, cited inBackx, 1991) are many times of lesser severity butcan nevertheless cause pain, distress, and may resultin absence from school and physical activity. Further-more, these injuries can lead to a recurrent injurywith further impairment.Varying results and incidence rates in the literature

are because of variations in study designs, methodo-logy, population, and injury definition employed,which unfortunately limit comparisons. Thereforean exact incidence rate is unknown, but accordingto Stanitski (1997) 20% of all participants in sports-related activities sustain an injury.

Injury definition and study limitation

In epidemiological investigations, an injury defini-tion most commonly includes an anatomical tissuediagnosis, medical treatment required and/or timelost from sport participation (Noyes et al., 1988).Rice (2000) defines an athletic injury as ‘‘a medicalcondition, resulting from athletic activity that causesa limitation or restriction on participation in thatactivity or for which medical treatment was re-ceived’’. We did not include the specific absence theday following the injury, which is otherwise a com-mon practice, since data from non-organized leisureactivities, with irregular participation, as well asphysical education classes were included. The stu-dents did, however, state if they were able to returnwithin a week or more.Pain conditions indicating chronic or overuse in-

juries were not included in this report. However,when analyzing the survey, seven students describedinjuries that made them unable to continue theirphysical activity, but these may have been causedby an overuse injury rather than an acute trauma.These injuries were not excluded from our results, asthey were an acute experience for the individualconcerned, resulting in them having to stop theiractivity and seek medical care as per our definition.Another 13 injuries were unspecified or were underongoing medical investigation.Memory biases and distortions are inherent in

most self-report measures and retrospective tech-niques, since incidents are forgotten, exaggeratedand/or diminished (van Mechelen, 1997b; Crockeret al., 1998). The subjective experience and toleranceof pain and injury differ not only from one person to


319

another, but also within an individual from time totime depending on circumstances. Also, an injurythat affects activity in one sport may not causeproblems for participation in another. Personal in-structions and one-to-one help may clear possibleconfusion, misinterpretation and eliminate socialdesirability and tendencies for indecisiveness or ex-treme responses in answers (Fox, 1998). In our studythe students had the opportunity to discuss theirinjuries with the test leader, to check if the incidencewas within the frame of our definition and recallperiod, as well as to a certain degree screen for over-and under-reporting. This was of special importancesince many children were eager to describe wintersport injuries that had occurred during the Christmasholiday, which because of our starting date at theonset of the spring term had to be excluded. On theother hand some students, especially boys, claimedthat certain injuries, i.e. thigh contusions in soccer,burn-wounds from artificial turf in rugby, etc. were‘‘part of the game’’, expected to happen, and theirailment was not looked upon as an injury.Our students reported injury incidents covering a

retrospective period of 3 months (January–March),which limits comparisons with studies using a differ-ent time period.In spite of the acknowledged limits of self-report

surveys, they provide comprehensive information inlarge-scale research studies, saving both time andmoney. Questionnaires answered either retrospect-ively or in connection with an accident can provideadditional important data on circumstances sur-rounding the incident, which are not evident indiagnostic reports provided in medical records.

Location, type and mechanism of injury

In scientific literature the prevalence of ‘‘site of ’’, aswell as ‘‘type of’’, injury and its mechanism are oftenpresented and discussed separately. They are, how-ever, often interrelated, and affected by age, genderand type of activity.Based on hospital data, children most often sustain

injuries in the upper extremities (Tursz & Crost,1986; Sahlin, 1990; Sorensen et al., 1996; Brudvik,2000; Kelm et al., 2001; Purvis & Burke, 2001).However, Backx et al. (1989) and Williams et al.(1998), also using self-reports, documented moreinjuries in the lower extremities, which is in linewith our findings. The fact that results differ maybe because of the age inclusion. Pre-school childrensustain more upper-extremity injuries but adoles-cents, the predominant age group in our study, andadults have more lower-extremity injuries (Purvis &Burke, 2001; Adirim & Cheng, 2003).Soft tissue injuries (sprains, strains and contu-

sions) represent the most prevalent type encountered

in (youth) sports medicine according to severalauthors (Stanitski, 1997; Kelm et al., 2001), whichis in agreement with our findings. Most injuredstudents in our study reported a fall as the mechan-ism, which also is in compliance with results fromother studies (Tursz & Crost, 1986; Brudvik, 2000).

Injury severity and primary care

For a complete description of the severity of sportsinjuries, van Mechelen (1997a) suggests the followingcriteria to be included: (1) nature of sports injury (amedical diagnosis), (2) duration and nature of treat-ment, (3) sports time lost, (4) working/school timelost, (5) permanent damage, and (6) cost of sportsinjuries. He further suggests that at least one of thelisted indicators should be addressed in the researchquestion.Apparently none of our students were permanently

damaged. Furthermore, the economic consequencesof their injuries were not further analyzed, but thismatter has been addressed in other studies (de Loes,1990; Sorensen et al., 1998). We did ask the studentsabout the diagnosis and treatment given to them, andwe have concentrated on time lost from sport whendiscussing the severity of the injury.According to both The National Athletic Trainers

Association, with data from 20 high schools parti-cipating in 18 sports, and The Athletic Health CareSystem (Seattle, USA) database, with over 60 000high school athletes having over 2.5 million days ofsport activities, most reported injuries (70–80%) areminor since the athletes were back in participationwithin 5–7 days (Rice, 2000). This is in line with ourfindings that 70% of the injured students were backin physical activities within a week.In Backx et al.’s (1989) study, a third (31%) of the

injuries required care from a physician and over halfof the injuries (53%) received no treatment at all. Inthe present study over 36% of the injured studentsdid not recall any special treatment after their injury.Also, when injury data are collected in the hospitalsetting, benign cases are left untreated, since Turszand Crost (1986) estimated that one-fourth of re-corded injuries never needed any medical care.Primary care of the injured student was, with the

exception of a family member, most often carried outby the physical education teacher or trainer, whichaccentuates the importance of ongoing sports medi-cine first aid education for this group (Abernethyet al., 2003).

Injuries during different settings

In this present study, more injuries were reportedduring leisure time activities and physical educationclass than during organized sports. This is in line

Sundblad et al.

320

with other studies like Zaricznyj et al. (1980) andBrudvik (2000), but contrary to the findings of Backxet al. (1989). The difference may be explained by asports club membership rate of 75% at age 10 yearsdropping to 59% at age 15 years in Backx’s study,compared with our rates of 49% at age 9 years and54% at age 15 years, of students active at least once aweek. Almost half of the school children (girls 44%and boys 56%) in our study reported that they wereactive at least twice a week in organized sports clubs.The prevalence of injuries in organized sports

clubs often reflect national ‘‘favorite sports’’ traditionswith high numbers of participants, such as soccer inSweden; soccer, handball and biking in Norway(Sahlin, 1990; Brudvik, 2000), and soccer, handballand horse-riding in Denmark (Sorensen et al., 1996).

Age and gender differences

Equal proportions of girls (17%) and boys (15%)reported an injury, with the exception of injuriesduring physical education class. The gender differ-ence in prevalence of injuries during physical educa-tion class in our survey is not in accordancewith Kelm et al.’s (2001) study of school sportsaccidents in Germany, who reported more injuriesamong boys.Physical education in Sweden is most often taught

in a coeducational setting. Since few studies onschool children have reported on this fact or havehad exposure rate information included, a directcomparison is not possible. In our survey, ballgames, during physical education class, causedmost of the injuries especially among girls (45% oftheir cases). In another part of this study, ball gameswere ranked as one of the favorite activities duringclass and this fact was also reflected in time spentplaying ball (grade 3: 21% and grade 9: 35% of theirlessons). In Kelm et al.’s (2001) study, 62% of theaccidents also occurred during ball games, and ac-cording to the authors 5% of all school children inGermany are seriously injured during physical edu-cation each year. Our data found 2.2 injured studentsper 1000 physical education hours. In Sorensens’(1996) article comparisons are made between studiesreporting incidence rates per 1000 students per year.Our data collected from a 3-month retrospectiveperiod cannot be extrapolated in a comparablemanner.Vision impairment was twice as common among

students injured during physical education class. In adifferent part of the survey the students reported thatless than half used glasses or lenses while active withsports. Some of the students may have had correctionfor reading and therefore would not need them whileexercising. Nevertheless, non-corrected vision im-

pairment may possibly be a risk factor for injuriesin school physical education.Williams et al. (1998) found in their study of sports

injuries among Scottish adolescents that boys hada higher prevalence of injuries, as well as a higherseverity (according to the AIS codes), than girls.Their finding concurs with other studies that con-clude higher incident rates among boys (Zaricznyjet al., 1980; Jacobsson et al., 1986) as well as moresevere injuries, than in girls (Sahlin, 1990). This dis-persion is often explained by higher exposure timeand intensity of male activities as well as a higherrisk-taking temperament. Our result may be explai-ned by the more equal exposure to sports activi-ties among Swedish school students and/or attribu-ted to reporting factors, since according to Williamset al. (1998) boys are less likely to report a minorinjury.Our results showed no statistically significant age

differences, which is in agreement with Williams et al.(1998). However, Tursz and Crost (1986) and Sahlin(1990) state that older children sustain more injuries,but their data also included pre-school children.Michaud et al. (2001) contributes an increase ofinjuries with age to pubertal maturity and exposureto specific activities. Hormonal changes during ado-lescents as the catalyst of more injuries is alsodiscussed by Kelm et al. (2001).

Injuries at different activity levels

Before drawing conclusions from injury incidents, wehave to consider, among many factors, the exposurerate. Several studies describe that the physicallyactive (with increased sports participation and in-tensity) are more likely to sustain an injury (Williamset al., 1998; Michaud et al., 2001), which is inlinewith our findings of injuries sustained during organ-ized sports. During physical education class, how-ever, in which the physically active and inactivestudents are together, an earlier Swedish study (deLoes et al., 1990) showed that injuries were moreoften sustained by the inactive students. In anotherpart of our study, the school children were askedseveral questions covering their physical activities, aswell as the intensity and frequency thereof. Anactivity index was constructed (see activity index inSetting at injury). We found no difference in injuryrate among the different physical activity levels dur-ing physical education class. It is possible that anincrease in awareness and educational considerationsof the physical disparity in the class can explain thedifference in injury rate observed by de Loes (1990)study 15 years ago.However, the risk of getting hurt while being

physically active must also be seen in relation tothe risk of being physically inactive. The latter is


321

linked to many diseases and disorders and is prob-ably a greater threat to our children.

Perspectives

The rate of injuries during physical education classand leisure activities suggests further measures, de-velopment of safety education programs and guide-lines for injury prevention in school children (Purvis& Burke, 2001).Research identifying the injury-prone child should

in the future have a holistic approach and thereforealso include psychological features (van Mechelen,1997b) and behavioral characteristics as suggested byBrudvik (2000). Furthermore, an increased aware-ness of physical maturation, physiological, motorcontrol and psychological changes in the youngathlete, especially during the onset of puberty, isimportant.An often recommended preventive measure for

sports injuries is a pre-season medical check-up(Hergenroeder, 1998; Adirim & Cheng, 2003). Thisis not a common practice for young Swedish athletesand may be a too ambitious commission for clubs,crouching under economic and personal burdens toadminister. Establishing a dialogue and collabora-

tion between doctors, physical education teachersand the sports club trainer might be a feasiblealternative.Focus for sports traumatology in the future gears

towards a proactive multidisciplinary preventive ap-proach, based on epidemiological injury surveillance.Preventive measures have during the last decadescontributed to a decreased morbidity and mortalityrate in other health care areas and its model caneasily be applied to sports injury prevention as well(Bischoff & Perrin, 1999).

Key words: physical education class, organized sportsclub, leisure activities.

Acknowledgements

Our sincere thanks to the entire research group who workedwith this study, for their inspiration and support and espe-cially to our scientific leaders, the Stockholm UniversityCollege of Physical Education and Sports, Anna Jansson(RPT), and all the fantastic school children throughoutSweden who made it all possible. We wish to express ourgratitude for financial support from the National Centre forResearch in Sports (CIF) and Majblomman. A special thanksto Anders Wallin (MD, PhD) and Johan Brun (MD) forexpert assistance.

References

Abernethy L, MacAuley D, McNally O,McCann S. Immediate care of schoolsport injury. Inj Prev 2003: 9: 270–273.

Adirim TA, Cheng TL. Overview ofinjuries in the young athlete. SportsMed 2003: 33: 75–81.

Backx FJG. Sports injuries in youth,etiology and prevention. Medicaldissertation, University of Utrecht, TheNetherlands, 1991.

Backx FJG, Erich WBM, Kemper ABA,Verbeek ALM. Sports injuries inschool-aged children. An epidemiologicstudy. Am J Sports Med 1989: 17:234–240.

Bernhardt DT. The young athlete. In:Garrett WE, Kirkendall DT, SquireDL, eds. Principles and Practices ofPrimary Sports Medicine. Philadelphia,PA: Lippincott, Williams & Wilkins,2001: 87–91.

Bischoff C, Perrin DH. Injury prevention.In: Schenck RC, ed. Athletic Trainingand Sports Medicine, 3rd edn.Rosemont, IL: American Academy ofOrthopaedic Surgeons, 1999: 37–62.

Brudvik C. Child injuries in Bergen,Norway. Injury 2000: 31: 761–767.

Crocker PRE, Kowalski KC, GrahamTR. Measurement of copingstrategies in sport. In: Duda JL, ed.Advances in Sport and ExercisePsychology Measurement. Fitness

Information Technology Inc.,Morgantown, WV, 1998: 156.

de Loes M. Medical treatment and costsof sports-related injuries in a totalpopulation. Int J Sports Med 1990: 11:66–72.

de Loes M, Jacobsson B, Goldie I. Riskexposure and incidence of injuries inschool physical education at differentactivity levels. Can J Sport Sci 1990: 15:131–136.

Ekblom B, Astrand PO. Role of physicalactivity on health in children andadolescents. Acta Paediatr 2000: 89:762–764.

Ekstrand J. Soccer Injuries and their pre-vention. Linkoping University MedicalDissertation, No 130, Sweden, 1982.

Flynn JM, Lou JE, Ganley TJ. Preventionof sports injuries in children. Curr OpinPediatr 2002: 14: 719–722.

Fox KR. Advances in the measurement ofthe physical self. In: Duda JL, ed.Advances in Sport and ExercisePsychology Measurement. FitnessInformation Technology, Inc.,Morgantown, WV, 1998: 300.

Guy JA, Micheli LJ. Pediatric andadolescent athletes. In: Schenck RC, ed.Athletic Training and Sports Medicine,3rd edn. Rosemont, IL: AmericanAcademy of Orthopaedic Surgeons,1999: 799–816.

Hawkins D, Metheny J. Overuse injuriesin youth sports: biomechanicalconsiderations. Med Sci Sports Exerc2001: 33: 1701–1707.

Hergenroeder AC. Prevention of sportsinjuries. Pediatrics 1998: 101:1057–1063.

Jacobsson B, Bek-Jensen H, Jansson B.One year’s incidence of school accidentsand their severity in a Swedishmunicipality. Scand J Prim Health Care1986: 4: 213–217.

Jones SJ, Lyons RA, Sibert J, Evans R,Palmer SR. Changes in sports injuriesto children between 1983 and 1998:comparison of case series. J PublicHealth Med 2001: 23: 268–271.

Kelm J, Ahlhelm F, Pape D, Pitsch W,Engel C. School sports accidents:analysis of causes, modes, andfrequencies. J Pediatr Orthop 2001:21: 165–168.

Landry GL. Benefits of sportsparticipation. In: Sullivan JA,Andersson SJ, eds. Care of the YoungAthlete. Rosemont, IL: AmericanAcademy of Orthopaedic Surgeons andAmerican Academy of Pediatrics, 2000:1–8.

Maffulli N, Bruns W. Injuries in youngathletes. Eur J Pediatr 2000: 159: 59–63.

Michaud PA, Renaud A, Narring F.Sports activities related to injuries? A

Sundblad et al.

322

survey among 9–19 year olds inSwitzerland. Inj Prevent 2001: 7:41–45.

Morrow RJ, Jackson AW, Disch JG,Mood DP. Measurement andEvaluation in Human Performance,2nd end. Champaign, IL: HumanKinetics, 2000: 220.

Noyes FR, Lindenfeld TN, Marshall MT.What determines an athletic injury(definition)? Who determines an injury(occurrence)? Am J Sports Med 1988:16(Suppl 1): 65–68.

Purvis JM, Burke RG. Recreationalinjuries in children: incidence andprevention. J Am Acad Orthop Surg2001: 9: 365–374.

Rice SG. Risks of injury during sportsparticipation. In: Sullivan JA,Anderson SJ, eds. Care of the YoungAthlete. Rosemont, IL: American

Academy of Orthopaedic Surgeons andAmerican Academy of Pediatrics, 2000:9–18.

Sahlin Y. Sport accidents in childhood. BrJ Sports Med 1990: 24: 40–44.

Sorensen L, Larsen SE, Rock ND. Theepidemiology of sports injuries inschool-aged children. Scand J Med SciSports 1996: 6: 281–286.

Sorensen L, Larsen SE, Rock ND. Sportsinjuries in school-aged children.A study of traumatologic andsocioeconomic outcome. Scand J MedSci Sports 1998: 8: 52–56.

Stanitski CL. Pediatric and adolescentsports injuries. Clin Sports Med 1997:16: 613–633.

Tursz A, Crost M. Sports-related injuriesin children. A study of theircharacteristics, frequency, and severity,with comparison to other types of

accidental injuries. Am J Sports Med1986: 14: 294–299.

van Mechelen W. The severity of sportsinjuries. Sports Med 1997a: 24: 176–180.

van Mechelen W. Sports injurysurveillance systems. ‘‘One size fits all’’?Sports Med 1997b: 24: 164–168.

Wiese-Bjornstal DM, Shaffer SM.Psychosocial dimensions of sportinjury. In: Ray R, Wiese-Bjornstal DM,eds. Counseling in Sports Medicine.Champaign, IL; Human Kinetics, 1999:23–40.

Williams JM, Wright P, Currie CE,Beattie TF. Sports related injuries inScottish adolescents aged 11–15. Br JSports Med 1998: 32: 291–296.

Zaricznyj B, Shattuck LJ, Mast TA,Robertson RV, D’Elia G. Sports-related injuries in school-aged children.Am J Sports Med 1980: 8: 318–324.


323

Documents

Injuries during physical activity in school children