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

Soccer-Related Injuries Treated in Emergency Departments: 1990-2014

OBJECTIVE

To investigate the epidemiology of youth soccer-related injuries treated in emergency departments in the United States.

METHODS

A retrospective analysis was conducted of soccer-related injuries among children 7 through 17 years of age from 1990 through 2014 with data from the National Electronic Injury Surveillance System. Injury rates were calculated from soccer participation data.

RESULTS

An estimated 2 995 765 (95% confidence interval [CI], 2 309 112-3 682 418) children 7 through 17 years old were treated in US emergency departments for soccer-related injuries during the 25-year study period, averaging 119 831 (95% CI, 92 364-147 297) annually. The annual injury rate per 10 000 soccer participants increased significantly, by 111.4%, from 1990 to 2014. Patients 12 to 17 years old accounted for 72.7% of injuries, 55.5% of patients were male, and most injuries occurred in a place of sport or recreation (68.5%) or school (25.7%). Struck by (38.5%) and fell (28.7%) were the leading mechanisms of injury. Injuries most commonly were diagnosed as sprain or strain (34.6%), fracture (23.2%), and soft tissue injury (21.9%), and occurred to the upper extremity (20.7%), ankle (17.8%), and head or neck (17.7%). Concussions or other closed head injuries accounted for 7.3% of the injuries, but the annual rate of concussions/closed head injuries per 10 000 participants increased significantly, by 1595.6%, from 1990 to 2014.

CONCLUSIONS

This study is the first to comprehensively investigate soccer-related injuries and calculate injury rates based on soccer participation data among children at the national level. The increasing number and rate of pediatric soccer-related injuries, especially soccer-related concussions/closed head injuries, underscore the need for increased efforts to prevent these injuries.

Sport-Specific Yearly Risk and Incidence of Anterior Cruciate Ligament Tears in High School Athletes: A Systematic Review and Meta-analysis

BACKGROUND

Anterior cruciate ligament (ACL) injury rates are affected by frequency and level of competition, sex, and sport. To date, no study has sought to quantify sport-specific yearly risk for ACL tears in the high school (HS) athlete by sex and sport played.

PURPOSE

To establish evidence-based incidence and yearly risk of ACL tears in HS athletes by sex for sports performed at the varsity level across the majority of US high schools.

STUDY DESIGN

Meta-analysis.

METHODS

PubMed, EMBASE, and Cochrane Central Register of Controlled Trials were searched to identify all articles reporting ACL tears per athletic exposure in HS athletes. ACL injury incidence rates (IRs) by sex and sport were calculated via meta-analysis. State athletic association guidelines were used to determine the number of exposures per season to calculate yearly risk of ACL tears.

RESULTS

The search recovered 3779 unique articles, of which 10 met our inclusion criteria, for a total of 700 ACL injuries in 11,239,029 exposures. The IR was 0.062 injuries per 1000 exposures (95% CI, 0.058-0.067). Although more injuries were recorded in males than females, females had a higher rate of injury per exposure (relative risk, 1.57; 95% CI, 1.35-1.82). Relative risk was highest in basketball (3.80; 95% CI, 2.53-5.85) and soccer (3.67; 95% CI, 2.61-5.27). While boys' football had the highest number of ACL injuries at 273, girls' soccer had the highest IR (0.148; 95% CI, 0.128-0.172). In girls, the highest injury risks per season were observed in soccer (1.11%; 95% CI, 0.96%-1.29%), basketball (0.88%; 95% CI, 0.71%-1.06%), and lacrosse (0.53%; 95% CI, 0.19%-1.15%). In comparison, the highest risks for boys were observed in football (0.80%; 95% CI, 0.71%-0.91%), lacrosse (0.44%; 95% CI, 0.18%-0.90%), and soccer (0.30%; 95% CI, 0.22%-0.41%).

CONCLUSION

There is an approximately 1.6-fold greater rate of ACL tears per athletic exposure in HS female athletes than males. However, there is significant risk in both sexes, particularly in high-risk sports such as soccer, football, basketball, and lacrosse. Knowledge of sport-specific risk is essential for future injury reduction programs, parent-athlete decision making, and accurate physician counseling.

Anthropometrics, Physical Performance, and Injury Characteristics of Youth American Football

BACKGROUND

Prior research has described the anthropometric and physical performance characteristics of professional, collegiate, and high school American football players. Yet, little research has described these factors in American youth football and their potential relationship with injury.

PURPOSE

To characterize anthropometric and physical performance measures, describe the epidemiology of injury, and examine the association of physical performance measures with injury among children participating within age-based divisions of a large metropolitan American youth football league.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Demographic, anthropometric, and physical performance characteristics and injuries of 819 male children were collected over a 2-year period (2011-2012). Injury data were collected by the league athletic trainer (AT) and coaches. Descriptive analysis of demographic, anthropometric, and physical performance measures (40-yard sprint, pro-agility, push-ups, and vertical jump) were conducted. Incidence rates were computed for all reported injuries; rates were calculated as the number of injuries per 1000 athlete-exposures (AEs). Multinomial logistic regression was used to identify whether the categories of no injury, no-time-loss (NTL) injury, and time-loss (TL) injury were associated with physical performance measures.

RESULTS

Of the 819 original participants, 760 (92.8%) completed preseason anthropometric measures (mean ± SD: age, 11.8 ± 1.2 years; height, 157.4 ± 10.7 cm; weight, 48.7 ± 13.3 kg; experience, 2.0 ± 1.8 years); 640 (78.1%) players completed physical performance measures. The mean (±SD) 40-yard sprint and pro-agility measures of the players were 6.5 ± 0.6 and 5.7 ± 0.5 seconds, respectively; the number of push-ups and maximal vertical jump height were 16.5 ± 9.3 repetitions and 42.3 ± 8.4 cm, respectively. Players assigned to different teams within age divisions demonstrated no differences in anthropometric measures; 40-yard dash and pro-agility times differed significantly (P < .05) between players assigned to different teams. A total of 261 NTL and TL injuries were reported during 35,957 AEs (games: 22%, n = 7982 AEs; practices: 78%, n = 27,975 AEs). The overall incidence rate was 7.26 per 1000 AEs (95% CI, 6.37-8.14). Physical performance measures did not predict NTL or TL injuries (P > .05).

CONCLUSION

No practically meaningful differences existed in anthropometric or physical performance measures between teams within age-based levels of play. Findings suggest that age-only criterion for player groupings can evenly match in terms of physical performance.

The elite young athlete: strategies to ensure physical and emotional health

This article presents a current review of the risk of physical and psychological injury associated with participation in elite youth sport, and suggests strategies to ensure the physical and emotional health of these young athletes. Although there is lack of epidemiological data, especially with regard to psychological injury, preliminary data suggest that the risk of injury is high in this population. While there is lack of incident and follow-up data, there is also concern regarding burnout, disordered eating, and the long-term consequences of injury. Modifiable injury risk factors identified include postural control, competition anxiety, life events, previous injury, and volume of training. There are presently no studies designed to determine the effectiveness of injury prevention measures in elite youth sports. However, there is adequate evidence arising from injury prevention studies of youth sports participants - including neuromuscular training, protective equipment, mental training to enhance self-esteem, and sport rules modification - to prevent injuries in elite youth sports settings. Although not tested, psychosocial prevention strategies such as adoption of task-oriented coping mechanisms, autonomous support from parents, and a proactive organizational approach also show promise in injury prevention.

Risk assessment of back pain in youth soccer players

The purpose of this study is to identify several responsible parameters for back pain (BP) in youth soccer players to create a risk assessment tool for early prevention.

An iPad-based survey was used to screen for parameters in a cross-sectional study. This questionnaire includes items regarding anthropometric data, training habits and sports injuries and was put into practice with 1110 athletes. Sex (odds ratio (OR): 1.84), age group (1.48) and playing surface (1.56) were significantly associated with BP. A history of injuries especially to the spine and hip/groin increased the likelihood for evolving recurrent BP (1.74/1.40). Overall 15 factors seem to influence the appearance of pain and were integrated into a feasible nomogram. The nomogram provides a practical tool to identify the risks of developing BP for youth soccer players. Although most factors we identified are non-modifiable, this method allows to rank the importance of factors and especially their prevention treatments for athletes.

Examining Measures of Weight as Risk Factors for Sport-Related Injury in Adolescents

Objectives. To examine body mass index (BMI) and waist circumference (WC) as risk factors for sport injury in adolescents. Design. A secondary analysis of prospectively collected data from a pilot cluster randomized controlled trial. Methods. Adolescents (n = 1,040) at the ages of 11-15 years from two Calgary junior high schools were included. BMI (kg/m(2)) and WC (cm) were measured from direct measures at baseline assessment. Categories (overweight/obese) were created using validated international (BMI) and national (WC) cut-off points. A Poisson regression analysis controlling for relevant covariates (sex, previous injury, sport participation, intervention group, and aerobic fitness level) estimated the risk of sport injury [incidence rate ratios (IRR) with 95% confidence intervals (CI)]. Results. There was an increased risk of time loss injury (IRR = 2.82, 95% CI: 1.01-8.04) and knee injury (IRR = 2.07, 95% CI: 1.00-6.94) in adolescents that were overweight/obese; however, increases in injury risk for all injury and lower extremity injury were not statistically significant. Estimates suggested a greater risk of time loss injury [IRR = 1.63 (95% CI: 0.93-2.47)] in adolescents with high measures of WC. Conclusions. There is an increased risk of time loss injury and knee injury in overweight/obese adolescents. Sport injury prevention training programs should include strategies that target all known risk factors for injury.

A School-Based Injury Prevention Program to Reduce Sport Injury Risk and Improve Healthy Outcomes in Youth: A Pilot Cluster-Randomized Controlled Trial

OBJECTIVE

To examine a school-based high-intensity neuromuscular training (NMT) program in reducing sport injury risk and improving fitness in youth.

PARTICIPANTS

Students (ages 11-15) (n = 725) in physical education (PE) classes were randomized by school to intervention or control groups.

INTERVENTION

A 12-week high-intensity NMT program (including aerobic, strength, balance, and agility components) was designed to reduce sport injury risk and improve measures of fitness. The control program was a standard of practice warm-up (including running and stretching).

RESULTS

A Poisson regression model using an intent-to-treat analysis demonstrated a reduced risk of sport injury: incidence rate ratio (IRR)all injury = 0.30 (95% CI, 0.19-0.49), IRRlower extremity injury = 0.31 (95% CI, 0.19-0.51), IRRankle sprain injury = 0.27 (95% CI, 0.15-0.50), and IRRknee sprain injury = 0.36 (95% CI, 0.13-0.98). A change in waist circumference: -0.99 centimeters (95% CI, -1.84 to -0.14) and an increase in indirect measures of aerobic fitness: 1.28 mL·kg·min (95% CI, 0.66-1.90) in the intervention school compared with the control school also occurred.

CONCLUSIONS

A NMT program in junior high school PE class was efficacious in reducing sport-related injury and improving measures of adiposity and fitness in the intervention group.

Injury profile among elite male youth soccer players in a Swedish first league

This study investigated the injury profile among elite male youth soccer players in a Swedish first league during two seasons. The present cohort study is based on data collected during the 2013–2014 seasons. In total, 43 young elite male soccer players, aged 15 to 19 yr, were prospectively followed regarding injuries, time of exposure, injury location, type of injury, and injury severity. The overall incidence of injury in the present study was estimated to 6.8 injuries per 1,000 exposure hours and 15.5 and 5.6 injuries per 1,000 hr for matches and training, respectively. The single most common injury subtype was muscle strain (53%). The hip and groin were the most common locations for injuries. Thirty-one percent of the injuries were classified as severe injury and caused >28 days absence from training and match play. Both the injury incidence and the number of serious injury seems to be relatively high in youth elite players according to this study. Although the injury incidence seems to be slightly lower than in adult elite players the injuries seem to be more traumatic in youth elite players.

Risk Factors for Injuries in Professional Football Players

AIM

The aim of this study was to identify risk factors related to the occurrence of injuries in football players.

MATERIALS AND METHODS

The study included 216 football players from 12 teams in the elite football league. Football-related injury data were collected prospectively during the 2012/2013 competitive season. At baseline the following information was collected for the players: anthropometric measurements (weight, height, BMI, subcutaneous skinfolds), playing experience, injury history, physical fitness performance test (agility run), peak oxygen uptake. The incidence, type and severity of injuries and training and game exposure times were prospectively documented for each player.

RESULTS

Most of the players (n = 155, 71.7%) sustained the injures during the study period. The overall injury incidence during the regular season was 6.3 injuries per 1000 athlete-exposures (95% confidence interval, 4.31-9.67). Multivariate logistic regression analysis showed that playing experience (odds ratio [OR] = 0.44; 95% CI = 0.32-0.61, p < 0.01), age (OR = 2.05; 95% CI = 1.49-2.81, p < 0.01) and a previous injury (OR = 4.4; 95% CI = 2.14-9.07, p < 0.01) were significantly correlated to increased risk of injuries. Body mass index was not associated with risk of injury. Strains (34.19%) and sprains (25.81%) were the major injury types. Twenty-seven percent of injured players were absent from football for more than 1 month, with knee injuries (25.42%) being the most severe type.

CONCLUSION

The risk factors that increase injury rates in football players were previous injury, higher age and years of playing. Future research should include adequate rehabilitation program to reduce the risk of injuries.

Risk Factors for Noncontact Ankle Injuries in Amateur Male Soccer Players: A Prospective Cohort Study

OBJECTIVE

To determine whether nonmodifiable and modifiable risk factors [ankle dorsiflexion range of motion (ROM), lower limb power output, and balance], as identified in preseason screening, predict the risk of sustaining a noncontact ankle injury in amateur male soccer players during the training and competitive season.

DESIGN

Prospective cohort study.

SETTING

Amateur soccer competition (club and area representative teams).

PARTICIPANTS

Amateur soccer players (n = 210) aged ≥15 years.

ASSESSMENT OF RISK FACTORS (INDEPENDENT VARIABLES)

Height, weight, ankle dorsiflexion ROM, power (vertical jump) and balance (time of double-leg balanced stance on an electronic wobble board, maximum 20 seconds) measured in preseason screening.

MAIN OUTCOME MEASURES (DEPENDENT VARIABLE)

Incidence of noncontact ankle injury and exposure to both training and games, monitored during the competitive season following baseline measurement. Noncontact ankle injury was defined as any ankle injury not caused by a collision (with another player or object) resulting in a participant missing at least 1 game or training session.

RESULTS

Fourteen of the 210 participants (6.7%) sustained a noncontact ankle injury yielding an injury rate of 0.484 injuries per 1000 player hours. Lower limb power output scores <30 W/kg [odds ratio (OR), 9.20, 95% confidence interval (CI), 1.13-75.09, P = 0.038] and poorer balance scores (OR, 0.43, 95% CI, 0.21-0.89, P = 0.024) were associated with higher odds of injury.

CONCLUSIONS

Poorer lower limb power output and balance are risk factors for noncontact ankle injury among amateur soccer players. These deficits can potentially be identified by screening, providing opportunities to investigate prevention strategies.

Sex Differences in Reported Concussion Injury Rates and Time Loss From Participation: An Update of the National Collegiate Athletic Association Injury Surveillance Program From 2004-2005 Through 2008-2009

CONTEXT

Epidemiologic studies have identified differences in concussion incidence between the sexes. However, few authors to date have updated injury rates (IRs) and time loss between male and female concussed athletes.

OBJECTIVE

To examine sex differences in IRs and time loss in concussed National Collegiate Athletic Association (NCAA) athletes.

DESIGN

Descriptive epidemiologic study.

SETTING

National Collegiate Athletic Association athletics.

PATIENTS OR OTHER PARTICIPANTS

A total of 1702 concusssed NCAA athletes, consisting of 903 females and 779 males participating in soccer, basketball, ice hockey, lacrosse, softball, or baseball over a 5-year period from 2004-2005 through 2008-2009.

MAIN OUTCOME MEASURE(S)

Using the NCAA Injury Surveillance Program, athletic trainers reported concussions, athlete-exposures (AEs), and time loss across 10 NCAA sports. An IR is the number of injuries in a particular category divided by the number of AEs in that category.

RESULTS

During the study period, 1702 concussions were reported during 4 170 427 AEs for an overall total of 5.47 per 10 000 AEs. In sex-comparable sports, females had a 1.4 times higher overall concussion IR than males (IRs = 4.84 and 3.46, respectively), with greater rates in women's baseball/softball, basketball, ice hockey, and soccer than men. Female soccer and basketball players also displayed more time loss after concussion compared with male basketball and soccer players.

CONCLUSIONS

Female athletes sustained a higher rate of concussion and, in all sports except lacrosse, had greater time loss from concussion than male athletes. Additional research is needed on sex differences in time loss after concussions.

Trans-physeal anterior cruciate ligament reconstruction in adolescents

PURPOSE

The aim of the study was to evaluate, in a group of adolescents, the onset of varus-valgus deviations in the sagittal plane after performing a trans-tibial trans-epiphyseal technique of ACL reconstruction with a follow-up of at least 2 years.

METHODS

Seventy-one patients aged 12-15 years old (Tanner scale 3 and 4) have undergone ACL reconstruction with STG using arthroscopy. All patients were evaluated clinically using the visual analogue scale (VAS), the Lysholm score and the Tegner activity score at the time of surgery. All patients were reevaluated after a follow-up period of at least 2 years (T1) using the VAS, the Lysholm score, the Tegner activity score and radiographic studies in order to compare the operated limb with the healthy control limb.

RESULTS

Valgus difference exceeding 2° in the knee axis between the operated limb and the healthy control limb was observed only in three patients (4.2%: 95% CI 0.88-11.86%). The average difference was <1° (0.3°, 95% CI 0.0-0.55).

CONCLUSION

The trans-tibial trans-epiphyseal technique of ACL reconstruction, according to the results obtained, seems to be a valid alternative procedure, when performed by a skilled orthopaedic surgeon, offering an excellent safety profile and at the same time very good clinical results.

LEVEL OF EVIDENCE

IV.

Epidemiology of injuries in female high school soccer players

BACKGROUND

Sport is a compulsory activity in schools in South Africa. Female learners participating in soccer are more vulnerable to injuries than males.

OBJECTIVE

This study determined the epidemiology of injuries in female high school soccer players.

METHODS

A cross sectional survey captured the epidemiology of injuries in the players. The population included 200 players from 27 high schools in one district between the ages of 14 to 19 years. A self-administered questionnaire was used to collect data.

RESULTS

Only 85 scholars from 8 schools participated. From the 85 respondents, 31 (36.5%) sustained injuries. Only 61 injuries were reported by the injured players. The injury prevalence for the season was 36.5%. The rate of injury was 90 per 1000 athlete exposure hours during the season. The defenders and midfielders sustained the most injuries. Most injuries reported were contact in nature. More injuries occurred during training than during matches. The lower extremity (77.8%) was injured more than the upper extremity (22.2%). The knee (22.2%) and ankle (15.9%) were the most frequently injured body parts. Muscle injury was the most commonly reported followed by bruising.

CONCLUSION

Prevalence of injuries was high with the lower limb, specifically the knee and ankle being commonly injured.

Low Risk of Injuries in Young Adolescents Participating in Top-Level Karate Competition

BACKGROUND

Prospective studies on injuries in martial arts competition are scarce, especially those involving young practitioners, but the upsurge of children and adolescents taking part in organized training and competition in these sports requires clarification of the injury risk that they represent for youths.

HYPOTHESIS

Top-level karate competition for young adolescents (cadets, or 14- to 15-year-olds) has a low injury rate and can be safely promoted.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Prospective recording of the injuries resulting from all bouts in 3 consecutive World Karate Championships (2009, 2011, and 2013) for cadets was performed. Data were collected prospectively in situ with checklists that described competitor sex, bout category, and weight as well as injured area, diagnosis, mechanism of injury, severity, and treatment.

RESULTS

A total of 1020 bouts were reviewed, 671 in the male category and 349 in the female category. A total of 61 injuries were recorded. Of those, only 3 were time-loss injuries. During the 2009 and 2011 championships, there was 1 injury per 25.6 fights, while during the 2013 championship the number of injuries increased, with 1 injury per 10 fights (P = .003). There was no statistical difference in the total injury rate between the male and female categories (P = .71), with an odds ratio of 1.16 (95% CI, 0.52-2.55).

CONCLUSION

The injury rate for cadet top-level karate competition found in this prospective study is much lower than the rates previously published for karate or other martial arts competitions, but there seems to be a marked increase as more championships are held, which is a matter of concern.

Soccer Injuries in Players Aged 7 to 12 Years: A Descriptive Epidemiological Study Over 2 Seasons

BACKGROUND

As part of a risk-management approach, sound epidemiological data are needed to develop prevention programs. A recent review on soccer injuries of players younger than 19 years concluded that prospective data concerning children are lacking.

PURPOSE

To analyze the incidence and characteristics of soccer injuries in children aged 7 to 12 years.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

The present survey was a prospective descriptive epidemiological study on soccer injuries over 2 seasons in the Czech Republic and Switzerland. Exposure of players during training and match play (in hours) and injury data were reported by coaches via an Internet-based registration system. Location, type, and severity of injuries were classified according to an established consensus. Injury characteristics are presented as absolute numbers and injury incidence rates (injuries per 1000 hours of soccer exposure). An injury was defined as any physical complaint sustained during a scheduled training session or match play resulting in at least 1 of the following: (1) inability to complete the current match or training session, (2) absence from subsequent training sessions or matches, and (3) injury requiring medical attention.

RESULTS

In total, 6038 player-seasons with 395,295 hours of soccer exposure were recorded. The mean (±SD) age of the players was 9.5 ± 2.0 years, and 3.9% of the participants were girls. A total of 417 injuries were reported. Most (76.3%) injuries were located in the lower limbs, with 15.6% located in the upper limbs. Joint and ligament injuries comprised 30.5%, contusions 22.5%, muscle and tendon injuries 18.5%, and fractures and bone injuries 15.4% of all injuries; 23.7% of injuries led to more than 28 days of absence from sport participation. The overall injury incidence was 0.61 (95% CI, 0.53-0.69) injuries per 1000 hours of soccer exposure during training sessions and 4.57 (95% CI, 4.00-5.23) during match play. Injury incidence rates increased with increasing age.

CONCLUSION

The observed injury incidences were lower compared with studies in youth players. Children showed a relatively high proportion of fractures and bone stress and of injuries to the upper limbs.

CLINICAL RELEVANCE

The study provides an evidence base for injury incidence rates and injury characteristics in children's soccer. These data are the basis to develop an age-specific injury-prevention program.

Agreement between High School Athletes and Their Parents on Reporting Athletic Events and Concussion Symptoms

An enhanced understanding of agreement levels between adolescents and parents for reporting athletic events and symptoms can help inform surveillance systems as well as clinical and epidemiological investigations of sports-related concussions. We sought to quantify agreement levels between high school athletes and parents for reporting: (1) number of games; (2) number of practices; (3) occurrence of an injury resulting in any concussion symptoms; and (4) presence of each specific symptom on the date of that injury among high school boys' football and girls' soccer athletes playing in Autumn 2012 in Washington State. There was substantial agreement on reporting the number of athletic events. Agreement levels were greater for games (kappa = 0.82; 95% confidence interval [CI]: 0.79-0.85 in boys' football; kappa = 0.75; 95% CI: 0.72-0.79 in girls' soccer) than for practices (kappa = 0.64; 95% CI: 0.62-0.67 in boys' football; kappa = 0.65; 95% CI: 0.62-0.67 in girls' soccer). There was moderate to substantial agreement on the occurrence of injury resulting in any concussion symptoms; however, agreement on the presence and severity of each symptom varied from poor to almost perfect. Overall, athletes reported greater severity of symptoms than parents did; notably, no difference in mean symptom scores was found when the athlete had a history of concussion. Agreement levels were greater when information was ascertained within 1 week of injury than when it was obtained later than 1 week. Including both athletes' and parents' reports of sports-related events and ascertaining information as soon as possible after injury are important considerations in designing injury surveillance systems.

Predictors of lower extremity injuries in team sports (PROFITS-study): a study protocol

INTRODUCTION

Several intrinsic risk factors for lower extremity injuries have been proposed, including lack of proper knee and body control during landings and cutting manoeuvres, low muscular strength, reduced balance and increased ligament laxity, but there are still many unanswered questions. The overall aim of this research project is to investigate anatomical, biomechanical, neuromuscular, genetic and demographic risk factors for traumatic non-contact lower extremity injuries in young team sport athletes. Furthermore, the research project aims to develop clinically oriented screening tools for predicting future injury risk.

METHODS

Young female and male players (n=508) from nine basketball teams, nine floorball teams, three ice hockey teams, and one volleyball team accepted the invitation to participate in this four-and-half-year prospective follow-up study. The players entered the study either in 2011, 2012 or 2013, and gave blood samples, performed physical tests and completed the baseline questionnaires. Following the start of screening tests, the players will be followed for sports injuries through December 2015. The primary outcome is a traumatic non-contact lower extremity injury. The secondary outcomes are other sports-related injuries. Injury risk is examined on the basis of anatomical, biomechanical, neuromuscular, genetic and other baseline factors. Univariate and multivariate regression models will be used to investigate association between investigated parameters and injury risk.

Sports injuries profile of a first division Brazilian soccer team: a descriptive cohort study

Objective:

To establish the injury profile of soccer players from a first division Brazilian soccer team. In addition, we investigated the association between the characteristics of the injuries and the player's age and position.

Method:

Forty-eight players from a Brazilian first division soccer team were followed during one season. Descriptive statistics were used to characterize the injury profile. Spearman's tests were used to verify the association between the number and severity of injuries and the player's age. Chi-square test was used to verify the association between type of injury and player's position. Fisher's exact test was used to verify the association between the severity of injuries and player's position.

Results:

The incidence of injuries was 42.84/1000 hours in matches and 2.40/1000 hours in training. The injury severity was 19.5±34.4 days off competition or training. Lower limb was the most common location of injury and most injuries were muscular/tendinous, overuse, non-recurrent, and non-contact injuries. Player's age correlated with the amount and severity of muscle and tendon injuries. Defenders had more minimal injuries (1-3 days lost), while forwards had more moderate (8-28 days lost) and severe injuries (>28 days lost). Furthermore, wingbacks had more muscle and tendon injuries, while midfielders had more joint and ligament injuries.

Conclusion:

The injury profile of the Brazilian players investigated in this study reflected regional differences in soccer practices. Results confirm the influence of the player's age and position on the soccer injuries profile.

The impact of previous knee injury on force plate and field-based measures of balance

BACKGROUND

Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease. This study examines the association between youth sport-related knee injury and balance, 3-10years post-injury.

METHODS

Participants included 50 individuals (ages 15-26years) with a sport-related intra-articular knee injury sustained 3-10years previously and 50 uninjured age-, sex- and sport-matched controls. Force-plate measures during single-limb stance (center-of-pressure 95% ellipse-area, path length, excursion, entropic half-life) and field-based balance scores (triple single-leg hop, star-excursion, unipedal dynamic balance) were collected. Descriptive statistics (mean within-pair difference; 95% confidence intervals) were used to compare groups. Linear regression (adjusted for injury history) was used to assess the relationship between ellipse-area and field-based scores.

FINDINGS

Injured participants on average demonstrated greater medio-lateral excursion [mean within-pair difference (95% confidence interval); 2.8mm (1.0, 4.5)], more regular medio-lateral position [10ms (2, 18)], and shorter triple single-leg hop distances [-30.9% (-8.1, -53.7)] than controls, while no between group differences existed for the remaining outcomes. After taking into consideration injury history, triple single leg hop scores demonstrated a linear association with ellipse area (β=0.52, 95% confidence interval 0.01, 1.01).

INTERPRETATION

On average the injured participants adjusted their position less frequently and demonstrated a larger magnitude of movement during single-limb stance compared to controls. These findings support the evaluation of balance outcomes in the period between knee injury and post-traumatic osteoarthritis onset.

Outcomes associated with early post-traumatic osteoarthritis and other negative health consequences 3-10 years following knee joint injury in youth sport

OBJECTIVE

Post-traumatic osteoarthritis (PTOA) commonly affects the knee joint. Although the risk of PTOA substantially increases post-joint injury, there is little research examining PTOA outcomes early in the period between joint injury and disease onset. Improved understanding of this interval would inform secondary prevention strategies aimed at preventing and/or delaying PTOA progression. This study examines the association between sport-related knee injury and outcomes related to development of PTOA, 3-10 years post-injury.

DESIGN

This preliminary analysis of the first year of a historical cohort study includes 100 (15-26 years) individuals. Fifty with a sport-related intra-articular knee injury sustained 3-10 years previously and 50 uninjured age, sex and sport matched controls. The primary outcome was the 'Symptoms' sub-scale of the Knee Osteoarthritis and Injury Outcome Score (KOOS). Secondary outcomes included; the remaining KOOS subscales, body mass index (BMI), hip abductor/adductor and knee extensor/flexor strength, estimated aerobic capacity (VO2max) and performance scores on three dynamic balance tests. Descriptive statistics (mean within-pair difference; 95% Confidence interval (CI) and conditional odds ratio (OR, 95% CI; BMI) were used to compare study groups.

RESULTS

Injured participants demonstrated poorer KOOS outcomes [symptoms -9.4 (-13.6, -5.2), pain -4.0 (-6.8, -1.2), quality-of-life -8.0 (-11.0, -5.1), daily living -3.0 (-5.0, -1.1) and sport/recreation -6.9 (-9.9, -3.8)], were 3.75 times (95% CI 1.24, 11.3) more likely to be overweight/obese and had lower triple single leg hop scores compared to controls. No significant group differences existed for remaining balance scores, estimated VO2max, hip or knee strength ratios or side-to-side difference in hip abductor/adductor or quadricep/hamstring strength.

CONCLUSIONS

This study provides preliminary evidence that youth/young adults following sport-related knee injury report more symptoms and poorer function, and are at greater risk of being overweight/obese 3-10 years post-injury compared to matched uninjured controls.

Epidemiology of injury in male adolescent Gaelic games

OBJECTIVES

There is a lack of epidemiological research in adolescent Gaelic games, with previous research primarily focusing on elite adult males. This study aimed to prospectively capture the epidemiology of injury in male adolescent Gaelic games over one year.

DESIGN

Prospective cohort study.

METHODS

Two hundred and ninety two (15.7±0.8 years) male adolescent Gaelic footballers and hurlers took part in a one year prospective epidemiological study. Injuries were assessed weekly by a certified Athletic Rehabilitation Therapist and an injury was defined as any injury sustained during training or competition resulting in restricted performance or time lost from play. An injury report form was utilised to standardise injury information.

RESULTS

Match injuries were more frequent in Gaelic footballers (9.26 per 1000h) and hurlers (11.11 per 1000h) than training injuries (2.69 and 3.01 per 1000h, respectively). Over a quarter of injuries in adolescent Gaelic footballers (26.7%) and hurlers (26.5%) were overuse in nature. Recurrent injuries were also frequent, particularly in adolescent Gaelic footballers (47.3%). Lower limb injuries predominated (football 74.7%, hurling 58%), particularly in the knee (18.7%, 20.0%) and ankle (12.0%, 10.0%). Hamstring injuries were more frequent in footballers (13.3%), with lower back injuries more common in hurlers (22.0%). Minor injuries were common in hurling (61.7%), with moderate (20.8%) and severe (37.5%) injuries predominant in Gaelic football.

CONCLUSIONS

Injuries are frequent in adolescent Gaelic games and this study sets the scene for the establishment of injury prevention strategies for this at risk population.

OARSI Clinical Trials Recommendations: Design and conduct of clinical trials for primary prevention of osteoarthritis by joint injury prevention in sport and recreation

The risk of post-traumatic osteoarthritis (PTOA) substantially increases following joint injury. Research efforts should focus on investigating the efficacy of preventative strategies in high quality randomized controlled trials (RCT). The objective of these OARSI RCT recommendations is to inform the design, conduct and analytical approaches to RCTs evaluating the preventative effect of joint injury prevention strategies. Recommendations regarding the design, conduct, and reporting of RCTs evaluating injury prevention interventions were established based on the consensus of nine researchers internationally with expertise in epidemiology, injury prevention and/or osteoarthritis (OA). Input and resultant consensus was established through teleconference, face to face and email correspondence over a 1 year period. Recommendations for injury prevention RCTs include context specific considerations regarding the research question, research design, study participants, randomization, baseline characteristics, intervention, outcome measurement, analysis, implementation, cost evaluation, reporting and future considerations including the impact on development of PTOA. Methodological recommendations for injury prevention RCTs are critical to informing evidence-based practice and policy decisions in health care, public health and the community. Recommendations regarding the interpretation and conduct of injury prevention RCTs will inform the highest level of evidence in the field. These recommendations will facilitate between study comparisons to inform best practice in injury prevention that will have the greatest public health impact.

The effects of isolated ankle strengthening and functional balance training on strength, running mechanics, postural control and injury prevention in novice runners: design of a randomized controlled trial

BACKGROUND

Risk factors have been proposed for running injuries including (a) reduced muscular strength, (b) excessive joint movements and (c) excessive joint moments in the frontal and transverse planes. To date, many running injury prevention programs have focused on a "top down" approach to strengthen the hip musculature in the attempt to reduce movements and moments at the hip, knee, and/or ankle joints. However, running mechanics did not change when hip muscle strength increased. It could be speculated that emphasis should be placed on increasing the strength of the ankle joint for a "ground up" approach. Strengthening of the large and small muscles crossing the ankle joint is assumed to change the force distribution for these muscles and to increase the use of smaller muscles. This would be associated with a reduction of joint and insertion forces, which could have a beneficial effect on injury prevention. However, training of the ankle joint as an injury prevention strategy has not been studied. Ankle strengthening techniques include isolated strengthening or movement-related strengthening such as functional balance training. There is little knowledge about the efficacy of such training programs on strength alteration, gait or injury reduction.

METHODS/DESIGN

Novice runners will be randomly assigned to one of three groups: an isolated ankle strengthening group (strength, n = 40), a functional balance training group (balance, n = 40) or an activity-matched control group (control, n = 40). Isokinetic strength will be measured using a Biodex System 3 dynamometer. Running kinematics and kinetics will be assessed using 3D motion analysis and a force platform. Postural control will be assessed by quantifying the magnitude and temporal structure of the center of pressure trace during single leg stance on a force platform. The change pre- and post-training in isokinetic strength, running mechanics, and postural control variables will be compared following the interventions. Injuries rates will be compared between groups over 6 months.

DISCUSSION

Avoiding injury will allow individuals to enjoy the benefits of participating in aerobic activities and reduce the healthcare costs associated with running injuries.

TRIAL REGISTRATION

Current Controlled Trial NCT01900262.

A statewide assessment of youth sports- and recreation-related injuries using emergency department administrative records

PURPOSE

Adequate levels of physical activity are essential for health, but participation in sports and recreational physical activities is associated with an increased risk of injury. The present study quantifies the impact of sports- and recreation-related injuries (SRIs) for middle and high school-aged Kentucky children.

METHODS

The study describes unintentional injuries in 2010-2012 Kentucky emergency department (ED) administrative records for patients age 10-18 years. SRIs were identified based on external codes of injuries, according to the International Classification of Diseases, Ninth Revision, Clinical Modification.

RESULTS

A total of 163,252 ED visits by 10- to 18-year olds occurred during the study period, of which 31,898 (20%) were related to participation in physical activity. Males accounted for 70% of the SRIs. The primary mechanisms for SRIs were strikings (55%), falls (26%), and overexertion (13%). Superficial contusions (25%), sprains/strains (33%), and fractures (18%) were the primary diagnoses. The total charges billed for SRIs exceeded $40 million, or 19% of the total charges billed for all unintentional injury-related ED visits in this age group.

CONCLUSIONS

The present study revealed one fifth of all Kentucky ED visits, and ED charges billed for unintentional injury among youth aged 10-18 years were related to sport and recreation. In the absence of a dedicated SRI surveillance system, ED administrative records provide meaningful utility for conducting statewide assessments of adolescent SRIs.

High injury incidence in adolescent female soccer

BACKGROUND

Previous studies report varying rates of time-loss injuries in adolescent female soccer, ranging from 2.4 to 5.3 per 1000 athlete-exposures or 2.5 to 3.7 per 1000 hours of exposure. However, these studies collected data using traditional injury reports from coaches or medical staff, with methods that significantly underestimate injury rates compared with players' self-reports.

PURPOSE

The primary aim was to investigate the injury incidence in adolescent female soccer using self-reports via mobile telephone text messaging. The secondary aim was to explore the association between soccer exposure, playing level, and injury risk.

STUDY DESIGN

Descriptive epidemiology study and cohort study; Level of evidence, 2 and 3.

METHODS

During a full adolescent female soccer season in Denmark (February-June 2012), a population-based sample of 498 girls aged 15 to 18 years was included in the prospective registration of injuries. All players were enrolled on a team participating in Danish Football Association series. Soccer injuries and exposure were reported weekly by answers to standardized text message questions, followed by individual injury interviews. Soccer exposure and playing levels were chosen a priori as the only independent variables of interest in the risk factor analyses. Injury rates and relative risks were estimated using Poisson regression. Generalized estimation equations were used to take into account that players were clustered within teams.

RESULTS

There were 498 players who sustained a total of 424 soccer injuries. The incidence of injuries was 15.3 (95% CI, 13.1-17.8), the incidence of time-loss injuries was 9.7 (95% CI, 8.2-11.4), and the incidence of severe injuries was 1.1 (95% CI, 0.7-1.6) per 1000 hours of soccer exposure. Higher average exposure in injury-free weeks was associated with a lower injury risk (P value for trend <.001), and players with low exposure (≤1 h/wk) were 3 to 10 times more likely to sustain a time-loss injury compared with other players (P < .01). Playing level was not associated with the risk of time-loss injuries (P = .18).

CONCLUSION

The injury incidence in adolescent female soccer is high, and this includes many severe injuries. Players with low soccer participation (≤1 h/wk) have a significantly higher injury risk compared with players participating more frequently.

The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies

BACKGROUND

Ankle sprain is one of the most common musculoskeletal injuries, yet a contemporary review and meta-analysis of prospective epidemiological studies investigating ankle sprain does not exist.

OBJECTIVE

Our aim is to provide an up-to-date account of the incidence rate and prevalence period of ankle sprain injury unlimited by timeframe or context activity.

METHODS

We conducted a systematic review and meta-analyses of English articles using relevant computerised databases. Search terms included Medical Search Headings for the ankle joint, injury and epidemiology. The following inclusion criteria were used: the study must report epidemiology findings of injuries sustained in an observed sample; the study must report ankle sprain injury with either incidence rate or prevalence period among the surveyed sample, or provide sufficient data from which these figures could be calculated; the study design must be prospective. Independent extraction of articles was performed by two authors using pre-determined data fields.

RESULTS

One-hundred and eighty-one prospective epidemiology studies from 144 separate papers were included. The average rating of all the included studies was 6.67/11, based on an adapted version of the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guidelines for rating observational studies. 116 studies were considered high quality and 65 were considered low quality. The main findings of the meta-analysis demonstrated a higher incidence of ankle sprain in females compared with males (13.6 vs 6.94 per 1,000 exposures), in children compared with adolescents (2.85 vs 1.94 per 1,000 exposures) and adolescents compared with adults (1.94 vs 0.72 per 1,000 exposures). The sport category with the highest incidence of ankle sprain was indoor/court sports, with a cumulative incidence rate of 7 per 1,000 exposures or 1.37 per 1,000 athlete exposures and 4.9 per 1,000 h. Low-quality studies tended to underestimate the incidence of ankle sprain when compared with high-quality studies (0.54 vs 11.55 per 1,000 exposures). Ankle sprain prevalence period estimates were similar across sub-groups. Lateral ankle sprain was the most commonly observed type of ankle sprain.

CONCLUSIONS

Females were at a higher risk of sustaining an ankle sprain compared with males and children compared with adolescents and adults, with indoor and court sports the highest risk activity. Studies at a greater risk of bias were more likely to underestimate the risk of ankle sprain. Participants were at a significantly higher risk of sustaining a lateral ankle sprain compared with syndesmotic and medial ankle sprains.

Increase in upper extremity fractures in young male soccer players in the Netherlands, 1998-2009

Young male soccer players have been identified as a target group for injury prevention, but studies addressing trends and determinants of injuries within this group are scarce. The goal of this study was to analyze age-specific trends in hospital-treated upper extremity fractures (UEF) among boys playing soccer in the Netherlands and to explore associated soccer-related factors. Data were obtained from a national database for the period 1998-2009. Rates were expressed as the annual number of UEF per 1000 soccer players. Poisson's regression was used to explore the association of UEF with the number of artificial turf fields and the number of injuries by physical contact. UEF rates increased significantly by 19.4% in boys 5-10 years, 73.2% in boys 11-14 years, and 38.8% in boys 15-18 years old. The number of injuries by physical contact showed a significant univariate association with UEF in boys 15-18 years old. The number of artificial turf fields showed a significant univariate association with UEF in all age groups, and remained significant for boys aged 15-18 years in a multivariate model. This study showed an increase of UEF rates in boys playing soccer, and an independent association between artificial turf fields and UEF in the oldest boys.

iReport SportsPhysio Platform

An accumulation of scientific evidence has emerged during the 1980s and 1990s, that is, physical activity would have significant benefits on health and well-being. Consequently, increasing participation of people in physical activities over the last decades has also led to a growing number of sports injuries and, simultaneously, higher demands on financial resources in global healthcare systems. Today, sports injuries are seen as a major public health problem in many developed, as well as developing, countries. This article illustrates the importance of having a platform such as iReport SportsPhysio to address such a rising issue globally. iReport SportsPhysio is a Web-based platform directed to sports health professionals to provide standard sports injuries monitoring and surveillance at a national level. The platform supports the acquisition, analysis and dissemination of sports injuries information, allowing health professionals to register and analyze sports injuries across various sports populations. Essentially, the platform provides a mechanism to house diverse statistical data in the form of tables and charts to analyze injuries at three levels: (1) athlete level independently of where individual athlete practices; (2) specific sports level across organizations; and (3) sports organizations level. A module for a global analysis is also made available, which allows the iReport SportsPhysio to obtain the incidence and prevalence measures, besides the socioeconomics costs relating to sports injuries at a global level. In order to offer these features, the platform is based on a global sports injury data model with the goal of standardizing data related to sports injuries.

Procedures for assessing psychological predictors of injuries in circus artists: a pilot prospective study

Background

Research on psychological risk factors for injury has focused on stable traits. Our objective was to test the feasibility of a prospective longitudinal study designed to examine labile psychological states as risk factors of injury.

Methods

We measured psychological traits at baseline (mood, ways of coping and anxiety), and psychological states every day (1-item questions on anxiety, sleep, fatigue, soreness, self-confidence) before performances in Cirque du Soleil artists of the show “O”. Additional questions were added once per week to better assess anxiety (20-item) and mood. Questionnaires were provided in English, French, Russian and Japanese. Injury and exposure data were extracted from electronic records that are kept as part of routine business practices.

Results

The 43.9% (36/82) recruitment rate was more than expected. Most artists completed the baseline questionnaires in 15 min, a weekly questionnaire in <2 min and a daily questionnaire in <1 min. We improved the formatting of some questions during the study, and adapted the wording of other questions to improve clarity. There were no dropouts during the entire study, suggesting the questionnaires were appropriate in content and length. Results for sample size calculations depend on the number of artists followed and the minimal important difference in injury rates, but in general, preclude a purely prospective study with daily data collection because of the long follow-up required. However, a prospective nested case-crossover design with data collection bi-weekly and at the time of injury appears feasible.

Conclusion

A prospective study collecting psychological state data from subjects who train and work regularly together is feasible, but sample size calculations suggest that the optimal study design would use prospective nested case-crossover methodology.

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.

Survey-based analysis of risk factors for injury among dogs participating in agility training and competition events

OBJECTIVE

To identify potential risk factors for agility-related injuries among dogs.

DESIGN

Internet-based, retrospective, cross-sectional survey.

ANIMALS

3,801 privately owned dogs participating in agility training or trials.

PROCEDURES

A retrospective electronic survey was used to investigate potential risk factors for injury among dogs participating in agility-related activities. Respondents were handlers recruited through member lists of large canine agility associations in Canada and the United Kingdom and through promotion on an agility blog site. Variables evaluated included demographic information for handlers and dogs, exposure variables (eg, frequency of agility practice and competition in the past year), and use of preventive measures intended to keep dogs fit for agility (warmup, cooldown, or conditioning exercises; alternative therapeutic treatments [eg, acupuncture, massage, or chiropractic care]; or dietary supplement products).

RESULTS

Data were collected from 1,669 handlers of 3,801 agility dogs internationally; 1,209 (32%) dogs incurred ≥ 1 injury. Previous injury (OR, 100.5), ≤ 4 years of agility experience for dogs (OR, 1.5), use of alternative therapeutic treatments (OR, 1.5), and Border Collie breed (OR, 1.7) were associated with increased odds of injury. Handlers having 5 to 10 or > 10 years of experience (OR, 0.8 and 0.6, respectively) and dogs having > 4 years of experience in the sport (OR, 0.6) were associated with decreased odds of injury.

CONCLUSIONS AND CLINICAL RELEVANCE

Specific factors were associated with agility-related injuries in dogs. Educational prevention strategies should target at-risk populations in an effort to reduce potential injuries. Future research should focus on the biomechanical factors associated with agility-related injuries.

Risk factors for lower extremity injuries in elite female soccer players

BACKGROUND

The incidence of lower extremity injuries in female soccer players is high, but the risk factors for injuries are unknown.

PURPOSE

To investigate risk factors for lower extremity injuries in elite female soccer players.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Players in the Norwegian elite female soccer league (N = 12 teams) participated in baseline screening tests before the 2009 competitive soccer season. The screening included tests assessing maximal lower extremity strength, dynamic balance, knee valgus angles in a drop-jump landing, knee joint laxity, generalized joint laxity, and foot pronation. Also included was a questionnaire to collect information on demographic data, elite-level experience, and injury history. Time-loss injuries and exposure in training and matches were recorded prospectively in the subsequent soccer season using weekly text messaging. Players reporting an injury were contacted to collect data regarding injury circumstances. Univariate and multivariate regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ±1 standard deviation of change.

RESULTS

In total, 173 players underwent complete screening tests and registration of injuries and exposure throughout the season. A total of 171 injuries in 107 players (62%) were recorded; ligament and muscle injuries were the most frequent. Multivariate analyses showed that a greater body mass index (BMI) (OR, 1.51; 95% CI, 1.21-1.90; P = .001) was the only factor significantly associated with new lower extremity injuries. A greater BMI was associated with new thigh injuries (OR, 1.51; 95% CI, 1.08-2.11; P = .01), a lower knee valgus angle in a drop-jump landing was associated with new ankle injuries (OR, 0.64; 95% CI, 0.41-1.00; P = .04), and a previous knee injury was associated with new lower leg and foot injuries (OR, 3.57; 95% CI, 1.27-9.99; P = .02), whereas none of the factors investigated influenced the risk of new knee injuries.

CONCLUSION

A greater BMI was associated with lower extremity injuries in elite female soccer players.

CLINICAL RELEVANCE

Increased knowledge on risk factors for lower extremity injuries enables more targeted prevention strategies with the aim of reducing injury rates in female soccer players.

Descriptive epidemiology of injuries in a Brazilian premier league soccer team

Soccer, which has a large number of participants, has a high injury incidence that causes both financial and time burdens. Therefore, knowledge about the epidemiology of soccer injuries could allow sports-medicine professionals, such as physicians and physiotherapists, to direct their work in specific preventive programs. Thus, our aim was to conduct an epidemiological survey of injuries sustained by professional soccer players from the same team who participated in the Brazilian championship premier league in 2009. To this end, we evaluated retrospectively player medical records from the team, which included name, date of birth, position, date of injury, mechanism of injury, and type of injury. In the period of study, 95 injuries were recorded: 42 (44.2%) were recorded during matches, and 53 (55.8%) during the training period. Injuries occurred more frequently in midfielders and strikers. All injuries happened in the lower limb, most of the injuries were muscular, and most occurred as the result of collisions with other athletes. In summary, this study demonstrates that there is a need for greater safety awareness in the training environment.

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.

Assessing remedies for missing weekly individual exposure in sport injury studies

BACKGROUND

In sport injury epidemiology research, the injury incidence rate (IR) is defined as the number of injuries over a given length of participation time (exposure, eg, game hours). However, it is common that individual weekly exposure is missing due to requirements of personnel at every game to record exposure information. Ignoring this issue will lead to an inflated injury rate because the total exposure serves as the denominator of IR, where the number of injury cases were captured accurately.

PURPOSE

This paper used data collected from a large community cohort study in youth ice hockey as an example, and compared six methods to handle missing weekly exposure of individual players.

METHODS

The six methods to handle missing weekly exposures include available case analysis, last observation carried forward, mean imputation, multiple imputation, bootstrapping and best/worst case analysis. To estimate injury rate ratios (IRRs) between Alberta and Quebec, as in the original study, three statistical models were applied to the imputed datasets: Poisson, zero-inflated Poisson and negative binomial regression models.

RESULTS

The final sample for imputation included 2098 players for whom 12.5% of weekly game hours were missing. Estimated IRs and IRRs with CIs from different imputation methods were similar when the proportion of missing was small. Simulations showed that mean and multiple imputations provide the least biased estimates of IRR when the proportion of missing was large.

CONCLUSIONS

Complicated methods, like multiple imputation or bootstrap, are not superior over the mean imputation, a much simpler method, in handling missing weekly exposure of injury data where exposures were missing at random.

Pediatric sports injuries: an age comparison of children versus adolescents

BACKGROUND

Significant knowledge deficits exist regarding sports injuries in the young child. Children continue to engage in physically demanding, organized sports to a greater extent despite the lack of physical readiness, predisposing themselves to injury.

PURPOSE

To evaluate sports injuries sustained in very young children (5-12 years) versus their older counterparts (13-17 years) with regard to the type and location of injuries, severity, and diagnosis.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A retrospective chart review was performed on a 5% random probability sample (final N = 2133) of 5- to 17-year-old patients treated for sports injuries in the Division of Sports Medicine at a large, academic pediatric medical center between 2000 and 2009. Using descriptive statistics, correlates of injuries by age group, injury type, and body area are shown.

RESULTS

Five- to 12-year-old patients differed in key ways from older patients. Children in this category sustained injuries that were more often traumatic in nature and more commonly of the upper extremity. Older patients (13-17 years) were more likely to be treated for injuries to the chest, hip/pelvis, and spine. A greater proportion of the older children were treated for overuse injuries, as compared with their younger counterparts (54.4% vs. 49.2%, respectively), and a much larger proportion of these injuries were classified as soft tissue injuries as opposed to bony injuries (37.9% vs. 26.1%, respectively). Injury diagnosis differed between the 2 age groups. The 13- to 17-year age group sustained more anterior cruciate ligament injuries, meniscal tears, and spondylolysis, while younger children were diagnosed with fractures, including physeal fractures, apophysitis, and osteochondritis dissecans. The 5- to 12-year-old patients treated for spine injuries were disproportionately female (75.8%); most of these injuries were overuse (78.8%) and bony (60.6%); over one third of the youngest children were diagnosed with spondylolysis. Surgery was required in 40% of the injuries in the full sample.

CONCLUSION

Sports injuries to children differ by age in injury diagnosis, type, and body area. Older children sustain a greater proportion of overuse injuries classified as soft tissue in nature. Children of all ages are sustaining significant sports injuries that require surgical intervention.