Soccer injuries in adolescents

Prevalence of disabled throwing shoulder and its shoulder function among youth football goalkeepers

Aim

Although the football goalkeepers are overhead athletes, no studies have reported the prevalence of disabled throwing shoulder (DTS) and the shoulder function. Thus, this study aimed to investigate the prevalence of DTS among youth football goalkeepers and to determine the relationship among their shoulder functions.

Methods

Youth football goalkeepers, who participated in a pre-participation medical examination were included in the study. The questionnaire was handed out before the examination to determine the players' age, dominant hand, and shoulder pain history. If the player had a history of shoulder pain during ball throwing motion in the past, they were defined as goalkeepers with DTS. Physical examination of scapular positioning, scapular retraction and rotator cuff muscle strength, and ultrasonographic evaluation were performed.

Results

Six goalkeepers (16%) had a history of DTS among the 38 male youth football goalkeepers. The presence of scapular malpositioning, limitation of scapular retraction, and decrease in rotator cuff strength was significantly higher in goalkeepers with DTS than in those without DTS (p = 0.03, p < 0.001, p < 0.001, respectively). Three goalkeepers with DTS revealed ultrasonographic findings.

Conclusion

The prevalence of DTS among youth football goalkeepers was 16%. All these players had scapular malpositioning and limitation of scapular retraction. Scapular malpositioning and limitation of scapular retraction may be related to the DTS in youth football goalkeepers.

Level of evidence

Level IV.

Elite professional goalkeepers report high rate of sport resumption after shoulder surgery

PURPOSE

The aim of this study is to evaluate the return to sport after surgical treatment of shoulder injuries in professional goalkeepers in relationship with the mechanism of injury and the pattern of related shoulder lesions.

METHODS

Twenty-six shoulders in nineteen elite male professional soccer goalkeepers were retrospectively analyzed considering multiple diseases (instability, rotator cuff, biceps or other tendon injuries). Data was collected for injury modality and context, pathological findings, surgical procedures, time, level of return to sport, and complications.

RESULTS

The mechanism of injury was "mild trauma without contact" in 46% of the cases and 54% of injuries happened during training. 11 patients (42%) reported multiple pattern lesions and 9 patients (35%) classic anterior instability lesions. The mean time for return to differentiated training and unrestricted sport activity was 14 and 20.2 weeks, respectively. 15 athletes (62.5%) reported 100% return to sport, 4 (16.7%) to 90%, 1 (4.2%) to 85%, 3 (12.5%) to 80% and 1 athlete to 50%, stopping professional activity. 21% of the cases reported the persistence of some shoulder symptoms. 3 cases experienced a new injury. Patients with classic anterior instability had significantly lower age (30.7 vs 19.8 years, P = 0.001), experienced injury in different context and reported symptoms more frequently compared to multiple lesion patients (4/8 vs 0/10, P = 0.011).

CONCLUSION

Professional elite goalkeepers which required shoulder surgery for different causes demonstrated high-rate level of return to play despite the persistence of mild symptoms. The high frequency of multiple lesions, patients' characteristics, injury context and mechanism, increase the concern for injuries in overstressed shoulder for this category of sport.

LEVEL OF EVIDENCE

IV.

Shedding light on incidence and burden of physeal injuries in a youth elite football academy: A 4-season prospective study

INTRODUCTION

Physeal injuries have been overlooked in epidemiological research in youth sports. Our prospective study investigated the incidence, severity, and burden of physeal injuries in a youth elite football academy.

METHODS

In total, 551 youth male football players from under-9 to under-19 were included and observed over four consecutive seasons. Injuries involving the physis were diagnosed and recorded according to type, location, and diagnosis. Injury incidence (II), severity (days lost), and injury burden (IB) were calculated per squad per season (25 players/squad).

RESULTS

There were 307 physeal injuries: 262 apophyseal (85%), 26 physeal (9%), 2 epiphyseal (1%), and 17 other physeal injuries (5%) with 80% (n=245) causing time-loss. The overall mean incidence of time-loss physeal injuries was 6 injuries/squad-season, leading to a total of 157 days lost/squad-season. The U-16s had the highest burden with 444 days lost per squad-season [median: 20 (95% CI: 12-30) days; II: 10 (95% CI: 7.3.1-13.4)]. Apophyseal injuries of the hip-pelvis resulted in the greatest burden [median: 13 (95% CI: 10-17); II: 2.5 (95% CI: 2.1-3.0)]. Peak apophyseal injury incidence per body parts occurred in U-11 for foot-ankle (II: 2.4; 95% CI: 1.0-4.9), U-14 for knee (II: 4.5; 95% CI: 2.7-7.1), and U-17 for hip-pelvis (II: 6.4; 95% CI: 4.2-9.3).

CONCLUSION

Physeal injuries accounted for a quarter of all-time loss with the largest injury burden in U-16. Most physeal injuries involved the lower limb and affected the apophysis. Physeal and apophyseal injuries incidence, burden, and pattern vary substantially depending on age. Hip-pelvic apophyseal injuries accounted for the largest injury burden.

Growth and Maturity Status of Female Soccer Players: A Narrative Review

Reported mean ages, heights and weights of female soccer players aged <19 years in 161 studies spanning the years 1992-2020 were extracted from the literature or calculated from data available to the authors; 35 studies spanning the years 1981-2020 also included an indicator of biological maturation. Heights and weights were plotted relative to U.S. reference data. Preece-Baines Model 1 was fitted to moving averages to estimate ages at peak velocity. Maturity indicators included skeletal age, pubertal status, age at menarche, percentage of predicted adult height and predicted maturity offset. Heights and weights showed negligible secular variation across the time interval. Heights were slightly above or approximated the reference medians through 14 years old and then varied between the medians and 75th percentiles through 18 years old. Weights were above the reference medians from 9 to 18 years old. Mean ages at menarche ranged from 12.7 to 13.0 years. The trend in heights and weights suggested the persistence and/or selection of taller and heavier players during adolescence, while estimated age at peak height velocity (PHV) and ages at menarche were within the range of mean ages in European and North American samples. Data for skeletal and sexual maturity status were limited; predicted maturity offset increased linearly with mean ages and heights at prediction.

ORTHOPEDIC INJURIES IN SOCCER - AN ANALYSIS OF A PROFESSIONAL CHAMPIONSHIP TOURNAMENT IN BRAZIL

Objective:

To analyze the incidence of orthopedic injuries which occurred during a professional soccer championship in São Paulo, Brazil in 2010.

Methods:

This assessment collected data from the pre-season until the final stage of the championship.

Results:

We analyzed 227 professional players from eight of the top teams in this championship. Data were obtained for 71.02% of all games. The athletes were all male with a mean age of 23.1 years; the average number of injuries was 1.6 per athlete, with muscle injuries and sprains resulting from indirect origin predominating in the legs.

Conclusion:

Injuries were more frequent in forwards and outside backs, and players generally returned to play within one week of treatment. Level of Evidence III, Study of Non Consecutive Patients; Without Consistently Applied Reference “Gold” Standard.

Hip Strength as an Intrinsic Risk Factor for Lateral Ankle Sprains in Youth Soccer Players: A 3-Season Prospective Study

BACKGROUND

Numerous epidemiological studies have emphasized the burden of lateral ankle sprains in youth soccer players. However, no prospective study has identified intrinsic physical and modifiable risk factors for these injuries in this particular population. Although injury prevention programs in soccer incorporate proximal hip and core stability exercises, it is striking that the relationship between impaired proximal hip function and ankle sprains has not yet been prospectively investigated in youth soccer players.

HYPOTHESIS

This prospective study aimed to examine whether hip muscle strength is a risk factor for sustaining a lateral ankle sprain in youth soccer players. We hypothesized that decreased hip muscle strength would predispose youth soccer players to an increased risk of lateral ankle sprains.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

This study included a total of 133 male youth soccer players (age divisions U11-U17) for analysis. At the beginning of the season, anthropometric characteristics were collected and hip muscle strength was assessed using a handheld dynamometer. Injury registration was performed by the team medical staff during 3 consecutive seasons. A principal-component, multivariate Cox regression analysis was performed to identify potential risk factors for sustaining a lateral ankle sprain.

RESULTS

Twelve participants (18% of all reported injuries) sustained a lateral ankle sprain (0.36 per 1000 athletic-exposure hours). After adjustment for body size dependencies and other hip muscle forces, an increase in hip muscle extension force was associated with a significant decrease in the hazard of the injury (hazard ratio, 0.3; 95% confidence interval, 0.1-0.9; P = .028). No other study variable could be identified as a risk factor for lateral ankle sprains.

CONCLUSION

Reduced hip extension muscle strength is an independent risk factor for lateral ankle sprains in male youth soccer players. Other hip muscle strength outcomes were not identified as risk factors. Replication in larger samples with more injured cases is warranted to further ascertain the importance of this risk factor.

Injuries during football tournaments in 45,000 children and adolescents

Four percent of the world's population, or 265 million people, play football, and many players are injured every year. The present study investigated more than 1800 injuries in over 45,000 youth players participating in three consecutive international football tournaments in Denmark in 2012-2014. The aim was to investigate the injury types and locations in children and adolescent football players and the differences between genders and age groups (11-15 and 16-19 years of age). An overall injury rate of 15.3 per 1000 player hours was found. The most common injury location was lower extremities (66.7%), and the most common injury type was contusion (24.4%). Girls had a relative risk of injury of 1.5 compared with boys, p < .001, and they had a higher proportion of injuries to knee and lower leg, 23.8%, than boys, 19.0%, p < .01. Boys had a higher proportion of fracture, 6.8%, as opposed to 3.3% among girls, p < .001. In conclusion, we found the youngest girls to have a higher incidence of almost all injury categories than any other group. In general, the incidence of injury decreased with age. The study provides a detailed insight into the injuries that may be expected at a large youth football tournament. These findings are of great value for organizations and healthcare professionals planning similar events and for planning injury prevention strategies, which would be of special interest in the youngest female players in general.

Football injuries in children and adolescent players: are there clues for prevention?

Football (soccer) is the world's most popular sport with most players being younger than 18 years. Playing football can induce beneficial health effects, but there is also a high risk of injury. Therefore, it is necessary to implement measures for preventing injuries. The present review analyzes and summarizes published scientific information on the incidence and characteristics of football injuries in children and adolescent players to arrive at sound conclusions and valid considerations for the development of injury-prevention programs. A literature search was conducted up to November 2012. Fifty-three relevant scientific publications were detected. Thirty-two studies fulfilled the inclusion criteria for pooled analysis. Additional information from the remaining 21 studies was considered where appropriate to obtain a broader perspective on the injury problem in children and youth football. Training injury incidence was nearly constant for players aged 13-19 years, ranging from 1 to 5 injuries per 1,000 h training. Match injury incidence tended to increase with age through all age groups, with an average incidence of about 15 to 20 injuries per 1,000 match hours in players older than 15 years. Between 60 and 90 % of all football injuries were classified as traumatic and about 10-40 % were overuse injuries. Most injuries (60-90 %) were located at the lower extremities with the ankle, knee, and thigh being mostly affected. The frequency of upper-extremity and head/face injuries was higher in those studies that analyzed match injuries only. The most common injury types were strains, sprains, and contusions (10 up to 40 % each). There is some evidence that the risk of traumatic injuries and, in particular, of sustaining a fracture, contusion, or concussion was higher during match play than in practice sessions. Fractures were more frequent in children younger than 15 years than in older players. About half of all time-loss injuries led to an absence from sport of less than 1 week, one third resulted in an absence between 1 and 4 weeks, and 10 to 15 % of all injuries were severe. Separate data for players under the age of 11 years are almost absent. Maturation status seems to have an influence on injury characteristics, although evidence is not conclusive at this time. Three main areas seem to be of particular relevance for future prevention research in young football players: (1) the substantial number of severe contact injuries during matches, (2) the high number of fractures in younger players, and (3) the influence of maturation status and growth spurts.

Incidence and risk factors of lower leg fractures in Belgian soccer players

INTRODUCTION

Soccer is the world's most popular sport and one that is physically demanding and highly competitive. Consequently, the rate of injuries resulting from this sport is only increasing. It is estimated that 2-20% of all such injuries are fractures, one-third of which are located in the lower extremities. The aim of this epidemiological study was to investigate the incidence of lower-leg fractures (LLFs) in Belgian soccer players and determine the possible risk factors that lead to them.

METHODS

All injuries of players associated with the Royal Belgium Football Association (RBFA) were reported and collected in a nationwide registry. We retrospectively compared the incidence rate of and risk factors for LLFs in Belgian soccer players during two seasons, 1999-2000 and 2009-2010.

RESULTS

In total, 1600 fractures (3%) were located in the lower leg. After a decade, the number of LLFs remained unchanged. Ankle fractures were the most common (37%), followed by foot and tibia fractures (33% and 22%, respectively). The least common were fibula fractures, which accounted for just 9%. A higher incidence of every type of LLF was observed in older and amateur-level soccer players, when compared with their younger and professional counterparts. Male players experienced more tibia and foot fractures, whereas the incidences of ankle and fibula fractures were comparable with those in female soccer players. The vast majority of fractures occurred during soccer games.

CONCLUSION

Ankle fractures and foot fractures represented two-thirds of all fractures noted in this analysis. Male gender, recreational level and adult age were important risk factors for LLFs. After 10 years, the incidence of LLFs did not decrease. Given the socioeconomic impact of these injuries, improved prevention techniques are required to reduce their incidence, particularly with regard to the frequently occurring ankle and foot fractures in this population.

Injury surveillance during a 2-day national female youth football tournament in Kenya

OBJECTIVE

To analyse the incidence, characteristics and circumstances of injuries during a female youth amateur football tournament in Kenya.

DESIGN

14 injury recorders prospectively registered and classified all injuries during all matches. Four physiotherapists and two doctors supported the injury recorders.

SETTING

A 2-day Mathare Youth Sports Association (MYSA) inter-provincial football tournament for female players in Nairobi, Kenya. The tournament is organised by a non-governmental organisation (NGO).

PARTICIPANTS

938 females divided into three age groups (under 13 years (U13), under 16 years (U16) and over 16 years (O16)).

MAIN OUTCOME MEASUREMENTS

Overall injury incidence.

RESULTS

123 injuries occurred in 106 matches. The incidence of all injuries was 93.3 injuries/1000 h. Players in the U13 (relative risk (RR)=2.16, 95% CI 1.3 to 3.5; p=0.002) and U16 (RR=2.17, 95% CI 1.3 to 3.5; p=0.002) age groups had an increased risk of injury compared to the O16 group. Most injuries allowed the players to continue to play (n=98 of 121; 81%). For 15 (12%) of the injuries the player did not continue to play but was expected to fully participate in the following match, and eight of the injuries (6.1 injuries/1000 h) were expected to result in the player's absence from play for 1-7 days. The injuries most commonly affected the lower limb (n=100; 82%); contusions to the ankle (n=15; 12%) and foot/toe (n=15; 12%) were the most common specific injury types. Most acute injuries (89 of 113, 79%) were caused by player contact.

CONCLUSIONS

The incidence of injuries among female youth football players in a national tournament in Kenya was high, but time-loss injuries were rare. Playing football in a tournament organised by an NGO at the inter-provincial level was safe.

Orthopedic injuries in a formation of a soccer club

Introduction

Football is one of the most popular sports in the world with approximately 400 million practitioners. All physical activity generates an overload somewhere in the locomotor system, above all, in young athletes.

Objective

To conduct the epidemiological survey of orthopedic injuries in a medical department of the categories of junior soccer a football club in Curitiba.

Methods

Epidemiological survey of injuries in 310 different athletes during the 2009 and 2010 seasons.

Results

The number of recorded visits was 3.64 per athlete orthopedic complaints in two years. Furthermore, we find 2.88 injuries/1,000 hours of play, and the junior (under 20 and under 18) with the highest rate (3.05). The most frequent injury was contusion (32.15%), lower limbs, especially the thigh (3.94%). The higher incidence of injuries occurred in the Middle - campers (30.65%), being the training responsible for 88.31% of the complaints.

Conclusion

The epidemiological survey of medical care is a medical department is an important tool for analysis of the main complaints, as well as the primary means of prevention and maintaining the health of athletes.

Effect of a chicken comb extract-containing supplement on subclinical joint pain in collegiate soccer players

Much of our focus of attention has been on sub-clinical or subtle joint pain experienced by healthy soccer players. The present study aimed to determine at which joint such subclinical pains are the most prominent, and to examine the pain-relieving effect of a chicken comb extract (CCE)-containing supplement product (test product) on these athletes. A total of 46 collegiate soccer players, consisting of 24 leading and 22 substitute players, belonging to a university soccer team were enrolled for measuring the pains at 4 different joints (ankle, knee, hip and shoulder) using 3 pain subscales of a 100-mm visual analog scale (VAS) ('pain at rest', 'pain on pressing' and 'pain on moving'), and participated in a prospective, double-blind, controlled study. A total of 23 subjects each received the test product (4,800 mg/day) (test group) and placebo (placebo group) for 12 weeks. VAS pain scores of individual joints were evaluated at baseline and following 4, 8 and 12 weeks of the intervention. VAS scores for the 'pain on moving' subscale in 46 enrolled subjects were highest at the ankle joint, and thus the values (abbreviated as 'pain scores') were used as a parameter for efficacy assessment of the test product. Compared to the baseline, the pain scores were significantly decreased for the dominant foot (but not for the non-dominant foot) in the total subpopulation (at week 4; p<0.01) and the leading player subpopulation (at week 4; p<0.01 and at week 12; p<0.05) in the test group (n=19 and 11, respectively). In comparison between the test product and placebo groups, the pain scores were significantly changed for the dominant foot (p<0.05) at week 4 in the total subpopulation and at week 12 in the leading player subpopulation in the test group. Thus, subclinical joint pain is most prominently observed at the ankle joint of the dominant foot in healthy young soccer players and may be improved by the daily intake of the CCE-containing supplement.

A 15-year prospective epidemiological account of acute traumatic injuries during official professional soccer league matches in Japan

BACKGROUND

Few prospective epidemiological studies on soccer match injuries have collected continuous data using subjects from the same group.

PURPOSE

To investigate long-term injury-induced changes during official matches in the professional Japanese soccer league.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Acute injuries during official matches among top-division Japanese professional soccer leaguers were prospectively collected from 1993 to 2007. Injuries preventing player participation for 7 days or more were defined as a reportable injury. Interseasonal variations of injury rate (IR: injuries/1000/player hours) and injury pattern (type, location, circumstances, severity, injury time, positional role, and relationship to weather) were analyzed.

RESULTS

Throughout the study period, 2947 injuries from 3984 matches occurred. Mean annual IR was 21.77/1000 player hours, and annual variance showed gradual decrement throughout the study period. The proportion of injury type and location were not significantly changed. Sprain and contusion as injury type and thigh and ankle joint as location were the most common in every season. Contact-related injuries comprised 73.3% on average and were observed to occur more frequently during the last 15 minutes and extra time of match play. The proportion of foul play-related injuries showed a clear declining trend. The proportion of severe injury showed a sporadic increase from 2001 to 2004. The second, fifth, and sixth 15-minute match segments showed a higher IR. Goalkeepers had a lower IR versus other field players. Matches on rainy days resulted in a lower IR than did those held under other weather conditions.

CONCLUSION

Long-term surveillance and statistical feedback of injury characteristics to organization members were considered effective in improving safer play awareness among players and for referees to reduce injury incidence, particularly foul play-related injuries.

Sport participation, sport injury, risk factors and sport safety practices in Calgary and area junior high schools

OBJECTIVES

To examine rates of sport participation, sport injury, risk factors and sport safety practices in young adolescents.

DESIGN

Cross-sectional.

SETTING

Calgary and area junior high schools.

PARTICIPANTS

A random sample of 1466 students (aged 12 to 15 years).

OUTCOME MEASURES

Sport injury within one year prior to completing the survey.

RESULTS

Ninety-three per cent of students participated in sports in the previous year. The injury rate was 60.85 injuries/100 students/year (95% CI 58.29 to 63.35) for students reporting at least one sport injury, 29.4 injuries/100 students/year (95% CI 27.08 to 31.81) for medically treated injuries, and 12.28 injuries/100 students/year (95% CI 10.64 to 14.07) for injuries presenting to a hospital emergency department. The greatest proportion of injuries occurred in basketball (14%), soccer (12%), hockey (8.6%) and snowboarding/skiing (7.1%).

CONCLUSIONS

The rates of participation and injury in sports are high in junior high school students. Future research should focus on prevention strategies in sports with high participation and injury rates to have the greatest population health impact.

Chronic spinal cord injury in the cervical spine of a young soccer player

A 17-year-old male soccer player presented with numbness in the upper- and lower-left extremities of 6 months' duration. He had no apparent history of trauma but experienced neck pain during heading of the ball 5 years prior. A high-signal intensity area was seen on T2-weighted magnetic resonance imaging (MRI) of the cervical spine. No muscle weakness was observed. Hypoesthesia was observed in bilateral forearms, hands, and extremities below the inguinal region. Plain radiographs in the neutral position showed local kyphosis at C3/4. A small protrusion of the C3/4 disk was observed on T1-weighted MRI. A high-signal area in the spinal cord at the C3/4 level was observed on T2-weighted MRI, but this was not enhanced by gadolinium. Multiple sclerosis, intramedullary spinal cord tumor, sarcoidosis and malignant lymphoma, and spinal cord injury were all considered in the differential diagnosis. However, in view of the clinical, laboratory, and radiological investigations, we concluded that repeated impacts to the neck caused by heading of the ball during soccer induced a chronic, minor spinal cord injury. This contributed to the high-signal intensity change of the spinal cord in T2-weighted MRI. The present case demonstrates that repeated impact may cause chronic spinal cord injury. Soccer, American football, or rugby players presenting with neck or extremity symptoms should not be overlooked for the possibility of latent spinal cord injury, as this could present later development of more severe or unrecoverable spinal cord injuries.

Effective injury prevention in soccer

Sports participation is accompanied by risk of injury, and each specific sport has its own unique injury profile. One of the goals of a sports medicine professional is injury prevention, and the past decade has seen numerous reports on the outcomes of injury-prevention studies. Health care professionals have been particularly vigilant in attempting to reduce common injuries in soccer, beginning with work in the early 1980s to the rigorous randomized trials of today. The use of a structured, generalized warm-up program has been shown to be effective in preventing common soccer injuries, reducing overall injury rates by approximately 30%. Given the number of individuals who play soccer worldwide, any injury reductions will likely have an impact on public health. It is an important goal of the sports medicine community to inform physicians and other sports medicine professionals about the effectiveness of prevention programs to increase use and compliance.

Low risk of injuries among children playing organized soccer: a prospective cohort study

BACKGROUND

The injury rate in soccer is high, and studies have shown that the injury rate among players aged 16 years or older approaches that of adult players. However, little is known about the injury risk among the youngest players, that is, players between 6 and 12 years.

PURPOSE

To examine the risk of injuries in children 6 to 16 years old playing organized soccer.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Injuries were recorded prospectively throughout 1 season among 121 soccer teams (1879 players, aged 6-16 years) from 2 communities in the southeastern part of Norway.

RESULTS

A total of 159 players sustained 200 injuries, corresponding to an overall injury incidence of 2.2 per 1000 playing hours (95% confidence interval, 1.8-2.6) among boys and 2.0 injuries per 1000 hours (95% confidence interval, 1.4-2.5) among girls. The overall injury incidence was significantly higher (relative risk, 1.7; 95% confidence interval, 1.3-2.2) among older players (13-16 years; 2.6 injuries per 1000 hours, 95% confidence interval, 2.2-3.0) than among younger players (6-12 years; 1.6 injuries per 1000 hours, 95% confidence interval, 1.2-1.9). The injuries recorded in the youngest group were few and mainly mild.

CONCLUSION

The injury risk among young players (6-12 years) playing organized 5- or 7-a-side soccer is low, lower than that of adolescents and much lower than at the elite level. Soccer is a safe sport for children.

Prevention of injuries among male soccer players: a prospective, randomized intervention study targeting players with previous injuries or reduced function

BACKGROUND

This study was conducted to investigate whether the most common injuries in soccer could be prevented, and to determine if a simple questionnaire could identify players at increased risk.

HYPOTHESIS

Introduction of targeted exercise programs to male soccer players with a history of previous injury or reduced function in the ankle, knee, hamstring, or groin will prevent injuries.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 2.

METHODS

A total of 508 players representing 31 teams were included in the study. A questionnaire indicating previous injury and/or reduced function as inclusion criteria was used to divide the players into high-risk (HR) (76%) and low-risk (LR) groups. The HR players were randomized individually into an HR intervention group or HR control group.

RESULTS

A total of 505 injuries were reported, sustained by 56% of the players. The total injury incidence was a mean of 3.2 (95% confidence interval [CI], 2.5-3.9) in the LR control group, 5.3 (95% CI, 4.6-6.0) in the HR control group (P = .0001 vs the LR control group), and 4.9 (95% CI, 4.3-5.6) in the HR intervention group (P = .50 vs the HR control group). For the main outcome measure, the sum of injuries to the ankle, knee, hamstring, and groin, there was also a significantly lower injury risk in the LR control group compared with the 2 other groups, but no difference between the HR intervention group and the HR control group. Compliance with the training programs in the HR intervention group was poor, with only 27.5% in the ankle group, 29.2% in the knee group, 21.1% in the hamstring group, and 19.4% in the groin defined as having carried out the minimum recommended training volume.

CONCLUSION

The players with a significantly increased risk of injury were able to be identified through the use of a questionnaire, but player compliance with the training programs prescribed was low and any effect of the intervention on injury risk could not be detected.

Quantifying the risk of sports injury: a systematic review of activity-specific rates for children under 16 years of age

Injuries caused by sports and other forms of physical activity in young children constitute a significant public health burden. It is important to quantify this risk to ensure that the benefits of sport participation are not outweighed by the potential harms. This review summarises the literature reporting exposure-based injury rates for various forms of physical activity in children aged 15 years and younger. Forty eight studies were found, of which 27 reported injury rates per hourly based exposure measured and 21 reported injury rates according to some other measure. Fourteen different sports and activities were covered, mostly team ball sports, with soccer being the most widely studied. Injury definition and the method of ascertaining and measuring injuries differed between studies, which created a large variation in reported injury rates that did not necessarily represent actual differences in injury risk between activities. The highest hourly based injury rates were reported for ice hockey, and the lowest were for soccer, although the range of injury rates for both of these activities was wide. Very few studies have investigated sports-related injuries in children younger than 8 years or in unorganised sports situations.

Causation of injuries in female football players in top-level tournaments

BACKGROUND

Analyses of tackle parameters in injury situations have provided valuable information regarding men's football. However, there are no similar data for women's football.

OBJECTIVE

To categorise the tackle mechanisms leading to injury in elite women's football.

STUDY DESIGN

Retrospective video analysis of injury situations.

METHODS

Events associated with all reported injuries during six women's top-level tournaments were analysed on video recordings for tackle parameters.

RESULTS

More than half of all injuries were due to tackles from the side (52%, 103/200), whereas tackles from behind were much less commonly involved in injury situations (11%, 21/200). One-footed (65%, 130/200) and upper body (21%, 42/200) tackle actions were most common. Sliding-in tackles leading to injury were the least likely to be sanctioned by match referees. Tackling players (45%, 90/200) were almost as likely to be injured as the tackled player (55%).

CONCLUSION

The present study found differences between injury mechanisms in women's football and previously published data on men's football. Further research, especially using video analysis, is needed for a better understanding of risk situations in football.

Injuries among Swedish female elite football players: a prospective population study

Injury occurrence in all 12 female elite senior football teams in premiere league was registered during 1 year. Of 269 players, 129 (48%) sustained 237 injuries. The total injury incidence was 4.6/1000 h of football. The injury incidence during practice was 2.7 and during the game time was 13.9/1000 h. The highest injury incidence during practice was to the knee (0.8/1000 h) and thigh (0.5/1000 h), and during game time was to the knee (4.4/1000 h) and head (2.2/1000 h). In total, the location for the highest injury incidence was the knee with 1.5 injuries/1000 h of football. The majority of injuries (82%) were localized to the lower extremities. Sixty-six injuries (28%) were re-occurring injuries (re-injuries). The incidence of traumatic injuries was 3.3/1000 h of football and for overuse injuries 1.3/1000 h. Overuse injuries occurred mainly during the preseason and at the beginning of the spring season. Thirty-nine percent of the injuries were slight or minor causing absence from practice or game time of less than 1 week, 39% were moderate (absence 7-28 days) and 22% were major (absence more than 28 days). The major injuries occurred often owing to trauma and were mainly to the knee.

Risk factors for injury in indoor compared with outdoor adolescent soccer

BACKGROUND

There are limited data on the epidemiology of indoor soccer injuries.

PURPOSE

Injury rates and risk factors for injury in adolescent indoor and outdoor soccer in the same cohort of players will be identified and compared.

STUDY DESIGN

Cohort study (prevalence); Level of evidence, 2.

METHODS

The study population was a random sample of 21 adolescent (ages 13-17 years) outdoor soccer teams (N = 317). The subcohort included players continuing to play in the indoor soccer season (n = 142). The injury definition included any injury occurring in soccer that resulted in medical attention, the inability to complete a session, and/or missing a subsequent session.

RESULTS

The overall injury rate found in indoor soccer over 20 weeks was 4.45 injuries per 1000 player hours (95% confidence interval, 3.1-6.19). The overall injury rate found in the 13-week outdoor soccer season among a similar cohort was 5.59 injuries per 1000 player hours (95% confidence interval, 4.42-6.97). The relative risk of injury suggests that there was no significant difference between injury rates by age group or gender in indoor soccer compared with outdoor soccer. The risk of injury in the most elite division of play was greater in outdoor compared with indoor soccer (relative risk, 3.22; 95% confidence interval, 1.8-6.12). The most commonly injured body part in both indoor and outdoor soccer was the ankle, followed by the groin in indoor and the knee in outdoor soccer.

CONCLUSION

There were no significant differences in overall injury rates found by gender or age group for indoor compared with outdoor soccer. Future research should focus on injury prevention strategies to reduce lower extremity injury in indoor and outdoor adolescent soccer.

Incidence of injuries in elite French youth soccer players: a 10-season study

BACKGROUND

Research on age-related injury incidence in elite youth soccer is needed to identify high-risk groups.

PURPOSE

To investigate the incidence of soccer-related injuries in elite French youth players based at the Clairefontaine Football Center.

STUDY DESIGN

Cohort study (Prevalence); Level of evidence, 1.

METHODS

Injuries sustained by players in the younger than 14-, 15-, and 16-year-old age groups during 10 seasons were diagnosed and documented by a sports physician according to type, location, severity, the date the injury occurred, and playing position.

RESULTS

Altogether, 1152 injuries were documented across all age groups with 69.1% and 30.9% sustained during training and matches, respectively. A total of 4.8 injuries per 1000 hours' exposure time were recorded and 11.2 and 3.9 injuries per 1000 hours for matches and training, respectively. There was no significant difference in injury frequency between age groups. The youngest group sustained more training injuries (P < .05) and osteochondroses (P < .05) and fewer match injuries than did the oldest group. Injury incidence varied throughout the season, peaking in September in all groups. The majority of injuries lasted less than 1 week (60.2%), contusions were the predominant injury type (30.6%, P < .05), and the upper leg was the site most often injured (24.5%, P < .05).

CONCLUSION

Those players younger than 14 years incurred more injuries in training and sustained more growth-related overuse disorders. Older players were more often injured during matches. Injury incidence and the frequency of overuse disorders were highest early in the season.

Childhood soccer injuries treated in U.S. emergency departments

OBJECTIVES

Soccer, an increasingly popular sport among children in the United States, is a common precipitant to injury-related emergency department (ED) visits. The authors estimated the number of children treated in EDs for soccer-related injuries and described the nature of these injuries.

METHODS

Data from the 2000 National Electronic Injury Surveillance System All Injury Program were used to estimate the overall number and rate of soccer injuries in children, calculate injury rates per 1,000 children, and describe the body regions affected and types of injuries. Results were stratified by five-year age groups (5-9 years, 10-14 years, and 15-19 years).

RESULTS

Approximately 144,600 children sustained soccer-related injuries in 2000 for a rate of 2.36 injuries per 1,000 children. Injury rates increased with age (0.8, 5-9 year olds; 3.1, 10-14 year olds; 3.2, 15-19 year olds). Common types of injuries were strains/sprains (36.7%), fractures (23.0%), and contusions (20.9%). Fractures decreased with age; sprains/strains increased with age. Commonly injured body regions varied by age. Wrist and finger injuries were most common (12.7% and 12.4%, respectively) in the youngest group; in the 10-14-year-old group, ankle and wrist injuries were most common (15.7% and 13.6%, respectively). In the oldest age group, ankle injuries were most common (21.9%), followed by knee injuries (17.6%).

CONCLUSIONS

Substantial numbers of children were treated in EDs for soccer-related injuries. Injury types and affected body regions varied by age. Injury prevention efforts to reduce soccer-related injuries may need to be age specific.

Pediatric fractures of the foot and ankle

Distal tibial physeal injuries are common in children, accounting for 10% to 40% of all injuries to skeletally immature patients. This article describes the classification, treatment, and complications of distal tibial fractures, fractures of the talus and calcaneus, midfoot and tarsometatarsal injuries, metatarsal fractures, and fractures of the phalanges in children.

Análise epidemiológica de lesões no futebol de salão durante o XV Campeonato Brasileiro de Seleções Sub 20

INTRODUÇÃO: Vários autores têm investigado a incidência de lesões no futebol. Entretanto, poucos trabalhos têm analisado as lesões no Futebol de Salão. O objetivo deste estudo foi analisar a incidência, circunstâncias e características das lesões registradas no Futebol de Salão durante o XV Campeonato Brasileiro de Futebol de Salão Sub 20. MÉTODOS: Fisioterapeutas ou médicos de todas as seleções participantes do XV Campeonato Brasileiro de Futebol de Salão Sub 20 responderam a um questionário para investigar a ocorrência de lesões durante as partidas. A taxa de resposta foi de 100%. RESULTADOS: Um total de 32 lesões foi registrado durante as 23 partidas, com incidência de 1,39 lesão por partida ou 208,6 lesões por 1.000 horas/jogo. Aproximadamente 1 a 3 lesões por partida resultaram em afastamento de jogadores em partidas ou treinamentos. As lesões de contato eram predominantes em 65,62% (21 das 32 lesões) e a maioria dessas lesões não resultou no afastamento dos jogadores. CONCLUSÕES: O presente estudo observou que a incidência das lesões durante o XV Campeonato Brasileiro de Futebol de Salão Sub 20 foi semelhante à registrada em torneios de Futebol de Salão, mas superior aos achados em torneios de futebol, caracterizando a especificidade do esporte. Entretanto, circunstâncias e características são similares entre eles devido à semelhança de demanda do esporte.

Survey of sport participation and sport injury in Calgary and area high schools

OBJECTIVE

To examine (1) sport participation and (2) sport injury in adolescents.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective survey design. In total, 2873 adolescents were recruited from a random sample of classes from 24 Calgary and area high schools. Each subject completed an in-class questionnaire in March 2004.

MAIN OUTCOME MEASUREMENTS

Overall and sport-specific participation rates (number of sport participants/number of students completing survey). Overall and sport-specific injury rates (number of injuries/number of participants).

RESULTS

In the previous 1 year, 94% of students participated in sport. The top 5 sports by participation for males were basketball, hockey, football, snowboarding, and soccer, and for females, basketball, dance, volleyball, snowboarding, and soccer. The injury rate including only injuries requiring medical attention was 40.2 injuries/100 adolescents/y (95% CI, 38.4-42.1), presenting to a hospital emergency department was 8.1 injuries/100 adolescents/y (95% CI, 7.1-9.2), resulting in time loss from sport was 49.9 injuries/100 adolescents/y (95% CI, 48-51.8), and resulting in loss of consciousness was 9.3 injuries/100 adolescents/y (95% CI, 8.3-10.5). The greatest proportion of injuries occurred in basketball, hockey, soccer, and snowboarding. The top 5 body parts injured were the ankle, knee, head, back, and wrist. The top 5 injury types were sprain, contusion, concussion, fracture, and muscle strain. A previous injury was associated with 49% of the injuries and direct contact with 45% of injuries.

CONCLUSIONS

Rates of participation in sport and sport injury are high in adolescents. Future research should focus on prevention strategies in sports with high participation and injury rates to maximize population health impact.

Evaluation of risk factors for injury in adolescent soccer: implementation and validation of an injury surveillance system

BACKGROUND

There are limited data on the epidemiology of adolescent soccer injury across all levels of play.

HYPOTHESIS

Through implementation and validation of an injury surveillance system in adolescent soccer, risk factors for injury will be identified.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

The study population was a random sample of 21 adolescent soccer teams (ages 12-18). A certified athletic therapist completed preseason baseline measurements and did weekly assessments of any identified soccer injury. The injury definition included any injury occurring in soccer that resulted in 1 or more of the following: medical attention, the inability to complete a session, or missing a subsequent session.

RESULTS

Based on completeness of data in addition to validity of time loss, this method of surveillance has proven to be effective. The overall injury rate during the regular season was 5.59 injuries per 1,000 player hours (95% confidence interval, 4.42-6.97). Soccer injury resulted in time loss from soccer for 86.9% of the injured players. Ankle and knee injuries were the most common injuries reported. Direct contact was reported to be involved in 46.2% of all injuries. There was an increased risk of injury associated with games versus practices (relative risk = 2.89; 95% confidence interval, 1.69-5.21). The risk of injury in the under 14 age group was greatest in the most elite division. Having had a previous injury in the past 1 year increased the risk of injury (relative risk = 1.74; 95% confidence interval, 1.0-3.1).

CONCLUSION

There were significant differences in injury rates found by division, previous injury, and session type (practice vs game). Future research should include the use of such a surveillance system to examine prevention strategies for injury in adolescent soccer.

Soccer injury in the lower extremities

Information about soccer injuries is required to develop prevention and rehabilitation programmes. Most soccer injuries occur in the lower extremities. This type of injury is reviewed here. Definitions of injury, injury rate, injury percentage, mechanism of injury, anatomical region of injury, type of injury, and severity of injury are summarised. In each section, a description and summary of the data are provided. Finally, the limitations of the studies and suggestions to improve the investigation of soccer injuries are provided.

Head injuries in youth soccer players presenting to the emergency department

BACKGROUND

There has been recent concern about neuropsychological injuries experienced by soccer players, particularly related to the purposeful heading of the ball. There are few population based analyses examining whether this is a legitimate concern.

OBJECTIVES

To explore, using an existing injury surveillance system, one of many parts of this issue: acute injuries requiring emergency medical care experienced by youth soccer players.

METHODS

Descriptive epidemiological analysis of emergency department injury surveillance data (1996-2001) for youths aged 10-24 years from the Kingston sites of the Canadian Hospital Injury Reporting and Prevention Program.

RESULTS

A total of 1714 cases of soccer injury were identified (mean 286 a year); 235 (13.7%) involved diagnoses of injuries to the head. Leading mechanical factors resulting in head injury were contact with other players or persons (153/235; 65.1%) and balls (62/235; 26.4%). Heading was reported in 4/62 (6%) of the ball contact injuries, and attempted heading was reported in 15/153 (9.8%) of the cases involving person to person contact. Unspecified head to head contact between players was reported in 39 cases.

CONCLUSIONS

Minor head injuries that result in emergency medical treatment do not happen often in youth soccer, and very few can be attributed to the purposeful heading of the ball. Player contact injuries appear to be a more important injury control concern. This study informs one of many aspects of the soccer heading injury debate.

Injuries in women's professional soccer

OBJECTIVE

The injury data from the first two seasons of the Women's United Soccer Association (WUSA) were analysed to determine the injury incidence, anatomic location of injuries, and relation of player position.

METHODS

Injury data on 202 players from eight teams during the first two seasons of the WUSA were prospectively collected and analysed.

RESULTS

A total of 173 injuries occurred in 110 players with an overall injury incidence rate of 1.93 injuries per 1000 player hours. The incidence of injury during practice and games was 1.17 and 12.63 per 1000 player hours, respectively. Of the injuries 82% were acute and 16% were chronic. Most of the injuries (60%) were located in the lower extremities. Strains (30.7%), sprains (19.1%), contusions (16.2%), and fractures (11.6%) were the most common diagnoses and the knee (31.8%) and head (10.9%) were the most common sites of injury. Anterior cruciate ligament (ACL) injuries accounted for 4.6% of all injuries and the incidence of ACL tears was 0.09 per 1000 player hours (practice 0.04, game 0.90). Midfielders suffered the most injuries (p<0.007).

CONCLUSION

We conclude that the injury incidence in the WUSA is lower than the 6.2 injuries per 1000 player hours found in the corresponding male professional league (Major League Soccer); however, knee injuries predominate even in these elite female athletes.

The Football Association medical research programme: an audit of injuries in academy youth football

OBJECTIVES

To undertake a prospective epidemiological study of the injuries sustained in English youth academy football over two competitive seasons.

METHODS

Player injuries were annotated by medical staff at 38 English football club youth academies. A specific injury audit questionnaire was used together with a weekly return form that documented each club's current injury status.

RESULTS

A total of 3805 injuries were reported over two complete seasons (June to May) with an average injury rate of 0.40 per player per season. The mean (SD) number of days absent for each injury was 21.9 (33.63), with an average of 2.31 (3.66) games missed per injury. The total amount of time absent through injury equated to about 6% of the player's development time. Players in the higher age groups (17-19 years) were more likely to receive an injury than those in the younger age groups (9-16 years). Injury incidence varied throughout the season, with training injuries peaking in January (p<0.05) and competition injuries peaking in October (p<0.05). Competition injuries accounted for 50.4% of the total, with 36% of these occurring in the last third of each half. Strains (31%) and sprains (20%) were the main injury types, predominantly affecting the lower limb, with a similar proportion of injuries affecting the thigh (19%), ankle (19%), and knee (18%). Growth related conditions, including Sever's disease and Osgood-Schlatter's disease, accounted for 5% of total injuries, peaking in the under 13 age group for Osgood-Schlatter's disease and the under 11 age group for Sever's disease. The rate of re-injury of exactly the same anatomical structure was 3%.

CONCLUSIONS

Footballers are at high risk of injury and there is a need to investigate ways of reducing this risk. Injury incidence at academy level is approximately half that of the professional game. Academy players probably have much less exposure to injury than their full time counterparts. Areas that warrant further attention include the link between musculoskeletal development and the onset of youth related conditions such as Sever's disease and Osgood-Schlatter's disease, the significant number of non-contact injuries that occur in academy football, and the increased rates of injury during preseason training and after the mid season break. This study has highlighted the nature and severity of injuries that occur at academy level, and the third part of the audit process now needs to be undertaken: the implementation of strategies to reduce the number of injuries encountered at this level.

The effect of estrogen on ovine anterior cruciate ligament fibroblasts: cell proliferation and collagen synthesis

Estrogen has been implicated as a causal factor for anterior cruciate ligament injuries in women. Studies have demonstrated a decrease in anterior cruciate ligament fibroblast proliferation and collagen synthesis at supraphysiologic levels of estrogen in a rabbit model.

HYPOTHESIS

The authors hypothesized that physiologic levels of estrogen would have no significant effect on anterior cruciate ligament fibroblast proliferation and collagen synthesis in an ovine model.

METHODS

Anterior cruciate ligament fibroblasts were isolated from sheep knees using routine cell culture methods. The cells were exposed to 17beta-estradiol at physiologic concentrations of 2.2, 5, 15, 25, 250, and 2500 pg/ml. Cell proliferation was determined by cell counts on days 4 and 6. Collagen synthesis was determined by (3)H-proline incorporation on day 4. Immunohistochemistry was performed to detect estrogen receptors.

RESULTS

Immunohistochemistry demonstrated the presence of estrogen receptors in ovine anterior cruciate ligament fibroblasts. There was no significant difference in anterior cruciate ligament fibroblast proliferation or collagen synthesis regardless of 17beta-estradiol concentration.

CONCLUSIONS

Based on results of this study, and given the low turnover of collagen in ligaments, it is unlikely that a 2- to 3-day per month increase in circulating estrogen would result in rapid, clinically significant alterations in material properties of the anterior cruciate ligament in vivo. The etiology of noncontact anterior cruciate ligament injuries is complex and multifactorial in nature, meriting further investigation.

Muscle strains in soccer: a five-year survey of an Italian major league team

We analyzed muscle injuries collected from an Italian major-league soccer team during the period 1995-2000. We considered all the muscle accidents that had required a player to stand down for three or more days. Among the overall injuries, muscle accidents were the most frequent, representing 30% (103 cases), followed by contusions (28%), sprains (17%) and tendinopathies (9%). There was one recurrence involving the hamstring. Lack of training was one of the causes of such injuries; in fact the training/match ratio of those seasons (3.6 to 1) show that there was little time for training compared to the number of matches.

The major traumas in youth football

For 4 years we followed a group of football players in the youth division of a professional club, ranging in age from 9 to 19 years, and analyzed the major injuries, i.e., those which required them to be sidelined for at least 4 weeks. We observed 23 sprains, 16 fractures, 16 cases of osteochondrosis, 7 muscle lesions, 6 cases of groin pain (athletic pubalgia), and 4 tendonopathies. The most frequent sites were the knee (n=30) and the ankle (n=11); the trauma factor was predominant (65.2%) with respect to overuse; noncontact traumas were more numerous (63.8%) than those resulting from contrast. Of a total 72 cases 8 regarded goalkeepers, and the remaining 64 cases were distributed among the other positions. As regards the age categories we detected a prevalence of osteochondrosis, traumatic detachments, and some fractures in the younger players, while in the older athletes we observed more sprains, muscle lesions, and tendonopathies.

Epidemiology of athletic head and neck injuries

In this article, we review the available data on sporting injuries to the head and neck and discuss sport-specific injury risk and prevention strategies, as well as the costs of head and neck injuries.

Risk factors for injury in child and adolescent sport: a systematic review of the literature

OBJECTIVE

The objective of this systematic review of the literature is to identify risk factors and potential prevention strategies that may modify risk factors for injury in child and adolescent sport.

DATA SOURCES

Seven electronic databases were searched to identify potentially relevant articles. A combination of Medical Subject Headings and text words were used (athletic injuries, sports injury, risk factors, adolescent, and child).

STUDY SELECTION

This review is based on epidemiological evidence in which the data are original, an exposure and outcome are objectively measured, and an attempt is made to create a comparison group. Forty-five studies were selected for this review.

DATA EXTRACTION

The data summarized include study design, study population, exposures, outcomes, and results. Estimates of odds ratios or relative risks were calculated where study data were adequate to do so. The quality of evidence is based on internal validity, external validity, and causal association.

DATA SYNTHESIS

There is some evidence that potentially modifiable risk factors including poor endurance, lack of preseason training, and some psychosocial factors are important risk factors for injury in child and adolescent sport. Concerns with study design, internal validity, and generalizability persist. The evidence is consistent, however, with more convincing evidence from adult population studies. The evidence for nonmodifiable risk factors for injury in adolescent sport (ie, age, sex, previous injury) is consistent among studies.

CONCLUSIONS

Sport participation and injury rates in child and adolescent sport are high. This review will assist in targeting the relevant groups and designing future research examining risk factors and prevention strategies in child and adolescent sport. Future clinical trials addressing modifiable risk factors to reduce the incidence of sports injury in this population are necessary.

Soccer injuries in childhood

A prospective study of soccer injuries, involving 287 male youth players, from the ages of 12-15 was conducted in 24 Greek soccer clubs, during the course of one year. A total of 193 players sustained 209 injuries. The incidence of injuries was 4.0 injuries per 1000 h of soccer time per player, and the most common types of injuries were sprains and strains. Surprisingly, it was found that an increase of injury incidences occurred during practice. Fifty-eight injuries required medical assistance. The majority of injuries (80%) were located in the lower extremities. Collision with other players was the most common activity at the time of injury, accounting for 40% of all injuries. The conclusion of this study and the evidence from other studies suggests that youth soccer is a relatively low risk sport. However, a substantial amount of injuries could be prevented. It is necessary to identify the risk factors, which are associated with these types of injuries.

Football incident analysis: a new video based method to describe injury mechanisms in professional football

OBJECTIVES

To develop and test a new video based method for match analysis that combines football specific and medical information to achieve a better understanding of the injury mechanisms and events leading up to high risk situations.

METHODS

Football incident analysis (FIA) is a video based method describing incidents that may result in an injury using 19 variables and categories modified from match analysis. Videos from 35 of 76 (46%) official Norwegian under 21 matches played from 1994 to 1998 were analysed. Two football experts classified each incident on the basis of predetermined criteria, and their results were compared using interobserver and intraobserver reliability tests.

RESULTS

kappa correlation coefficients for interobserver and intraobserver agreement were very good for 63% and 95% and good for 37% and 5% of the variables respectively. Fifty two incidents were recorded (1.6 incidents per team per match or 94 per 1000 player hours), and 16 (31%) led to injuries (0.5 injuries per match or 29 injuries per 1000 player hours). FIA results showed that 28 incidents occurred while attacking in midfield zone 2 or the attacking zone, and 24 took place while defending in the defensive zone or midfield zone 1. Midfielders were exposed in 67% of the incidents, mainly in breakdown attacks or during long attacks by the opposing team. Of the 28 incidents during offence, only one was classified as having great potential to score a goal. Most incidents (70%) were the result of tackling duels both in the offensive and defensive playing phases. Of the 21 offensive incidents resulting from tackling duels, in 19 cases the exposed player was unaware of the tackling (passive duellist).

CONCLUSIONS

This study shows that football incident analysis is a potentially valuable tool for understanding the events leading up to injuries in football.

Major international sport profiles

Sports are part of the sociocultural fabric of all countries. Although different sports have their origins in different countries, many sports are now played worldwide. International sporting events bring athletes of many cultures together and provide the opportunity not only for athletic competition but also for sociocultural exchange and understanding among people. This article reviews five major sports with international appeal and participation: cricket, martial arts, field hockey, soccer, and tennis. For each sport, the major aspects of physiological and biomechanical demands, injuries, and prevention strategies are reviewed.

Is it possible to prevent sports injuries? Review of controlled clinical trials and recommendations for future work

Sports injuries are one of the most common injuries in modern western societies. Treating sports injuries is often difficult, expensive and time consuming, and thus, preventive strategies and activities are justified on medical as well as economic grounds. A successful injury surveillance and prevention requires valid pre- and post-intervention data on the extent of the problem. The aetiology, risk factors and exact mechanisms of injuries need to be identified before initiating a measure or programme for preventing sports injuries, and measurement of the outcome (injury) must include a standardised definition of the injury and its severity, as well as a systematic method of collecting the information. Valid and reliable measurement of the exposure includes exact information about the population at risk and exposure time. The true efficacy of a preventive measure or programme can be best evaluated through a well-planned randomised trial. Until now, 16 randomised, controlled trials (RCT) have been published on prevention of sports injuries. According to these RCT, the general injury rate can be reduced by a multifactorial injury prevention programme in soccer (relative risk 0.25, p < 0.001, in the intervention group), or by ankle disk training, combined with a thorough warm-up, in European team handball [odds ratio 0.17; 95% confidence interval (CI) 0.09 to 0.32, p < 0.01]. Ankle sprains can be prevented by ankle supports (i.e. semirigid orthoses or air-cast braces) in high-risk sporting activities, such as soccer and basketball (Peto odds ratio 0.49; 95% CI 0.37 to 0.66), and stress fractures of the lower limb by the use of shock-absorbing insoles in footwear (Peto odds ratio 0.47; 95% CI 0.30 to 0.76). In future studies, it is extremely important for researches to seek consultation with epidemiologists and statisticians to be certain that the study hypothesis is appropriate and that the methodology can lead to reliable and valid information. Further well-designed randomised studies are needed on preventive actions and devices that are in common use, such as preseason medical screenings, warming up, proprioceptive training, stretching, muscle strengthening, taping, protective equipment, rehabilitation programmes and education interventions (such as increasing general injury awareness among a team). The effect of a planned rule change on the injury risk in a particular sport could be tested via a RCT before execution of the change. The most urgent needs are in commonly practised or high-risk sports, such as soccer, American football, rugby, ice hockey, European team handball, karate, floorball, basketball, downhill skiing and motor sports.

An examination of injuries in major league soccer. The inaugural season

We analyzed the injury data collected from the 10 teams (237 players) that constituted Major League Soccer during its inaugural season. The overall injury rate was 6.2 per 1000 hours of participation. An injury rate of 2.9 per 1000 hours was noted for practice and 35.3 per 1000 hours was found for games. The difference was statistically significant. With regard to severity, 36% of injuries (143 of 399) were categorized as an incident (no time lost from competition). Of the 256 injuries that caused the player to lose playing time, 59% were classified as minor (<7 days lost), 28% as moderate (7 to 29 days lost), and 13% as major (>30 days lost). Seventy-seven percent of the injuries (197 of 256) were to the lower extremity; most frequently affected were the knee (N = 54) and ankle (N = 46). Neither the player's age nor playing position was found to be associated with prevalence or severity of injury. We believe that this information serves to underscore the notion that soccer, as it is played at the professional level, is a sport with a relatively low incidence of injury.

10-year trend in USA Cup soccer injuries: 1988-1997

OBJECTIVE

To prospectively document the incidence of competition-related injury rates in an international youth soccer tournament and to analyze the type and location of injuries by age and gender.

DESIGN

A prospective injury report form completed for injured players presenting to a medical facility for evaluation by the medical staff.

SETTING

An international youth soccer tournament occurring annually during mid-July.

PARTICIPANTS

89,500 soccer players, ages 9-19. MEASUREMENT/MAIN RESULTS: A total of 3840 new, play-related injuries were evaluated during 290,344 player-hours of competition from 1988 through 1997. New, play-related injuries per 1000-player-hours decreased from 19.87 in 1988 to 9.89 in 1997. Female injury rates ranged from a maximum of 20.11 in 1989 to a minimum of 10.23 in 1996 and the male injury rate ranged from a maximum of 20.04 in 1988 to a minimum of 7.60 in 1996. The lowest injury rate occurred in the under-19 females (10.64) and highest rates occurred in under-16 (17.68) and under-15 (16.92) females. Heat illness correlated with mean temperature. The aggregate rate of heat illness was 0.6 cases/1000 player-hours under "normal" conditions compared to a rate of 2.8/1000 player-hours during "hot" years.

CONCLUSIONS

Injury rates for both genders declined over the 10-yr span of the USA Cup study. The aggregate rate of injury was slightly higher for females than males although the difference between male and female rates became less significant as the tournament matured. In conditions of extreme heat and humidity (1988 and 1995) the rate of new, heat illness increased compared with normal years and females were 1.6 times more likely to sustain heat illness than males.

Football injuries and physical symptoms. A review of the literature

Football is one of the most popular sports worldwide. The frequency of football injuries is estimated to be approximately 10 to 35 per 1000 playing hours. The majority of injuries occur in the lower extremities, mainly in the knees and ankles; the number of head injuries is probably underestimated. The average cost for medical treatment per football injury is estimated to be $150 (U.S. dollars). Considering the number of active football players worldwide, the socioeconomic and financial consequences of injury are of such a proportion that a prevention program to reduce the incidence of injuries is urgently required. For this reason, an analysis of intrinsic (person-related) and extrinsic (environment-related) risk factors was undertaken based on a review of the current literature. It was concluded that the epidemiologic information regarding the sports medicine aspects of football injuries is inconsistent and far from complete because of the employment of heterogeneous methods, various definitions of injury, and different characteristics of the assessed teams. The aim of this study was to analyze the literature on the incidence of injuries and symptoms in football players, as well as to identify risk factors for injury and to demonstrate possibilities for injury prevention.

Incidence of football injuries in youth players. Comparison of players from two European regions

Several authors have investigated the frequency of football injuries in youth players. However, the results of these studies are inconsistent because of the different age groups investigated and the different methods applied. The aim of the present study was to compare the incidence and characteristics of football injuries in youth players of two European regions. A total of 444 youth players from the Czech Republic and the Alsace region of France and Germany were followed weekly for 1 year. In 311 players (70%), complete weekly follow-ups over the 1-year period were available. The comparison of injury data revealed no substantial differences between players from the Alsace region and the Czech Republic in injury incidence per 1000 hours of exposure, degree of injury severity, or the circumstances in which the injuries occurred. However, players from the Czech Republic spent more time in training and playing football than did players from the Alsace region, and in the Czech Republic a higher proportion of injuries was caused by foul play. With only a few exceptions, the statistics were similar in the amount of football played as well as in the incidence of injury between different age and skill levels in both European regions.