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.     

Comparison of 3 preventive methods to reduce the recurrence of ankle inversion sprains in male soccer players

BACKGROUND: Ankle sprains are frequent injuries in soccer. Several strategies can be used to prevent further ankle sprains in athletes: the most common are proprioceptive training, strength training, and orthoses. OBJECTIVE: To investigate which of these 3 interventions is the most effective in preventing ankle sprains in athletes with previous ankle inversion sprain. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS AND MEASURES: Eighty male soccer players (age, 24.6 +/- 2.63 years; height, 175.60 +/- 4.36 cm; weight, 64.26 +/- 8.37 kg) in the first division of a men's league who had experienced previous ankle inversion sprain were randomly selected from an original population of 120 players. The subjects were individually and randomly assigned to 4 study groups: group 1 (n = 20) followed the proprioceptive program, group 2 (n = 20) followed the strength program, group 3 (n = 20) used orthoses, and group 4 (n = 20) was the control group. Data on the frequency of ankle sprain reinjury were collected at the end of the session. RESULTS: There were no significant differences among the groups in the number of exposures. The incidence of ankle sprains in players in the proprioception training group was significantly lower than in the control group (relative risk of injury, 0.13; 95% confidence interval, 0.003-0.93; P = .02). The findings with respect to the strength and orthotic groups in comparison with the control group were not significant (relative risk of injury, 0.5; 95% confidence interval, 0.11-1.87; P = .27 for strength; relative risk of injury, 0.25; 95% confidence interval, 0.03-1.25; P = .06 for orthotic group). CONCLUSION: Proprioceptive training, compared with no intervention, was an effective strategy to reduce the rate of ankle sprains among male soccer players who suffered ankle sprain.     

The association of padded headgear with concussion and injury risk in junior Australian football: A prospective cohort study

ObjectivesTo assess whether padded headgear was associated with incidence of suspected sports-related concussion, non-sports-related concussion head injury, and injuries to other body regions in junior Australian football.DesignProspective cohort injury surveillance.MethodsThere were 400 junior players (42.5% female) enrolled across two seasons. Suspected sports-related concussion was defined by detection of observable signs on the field and medical assessment or missed match(es) due to suspected sports-related concussion. Non-sports-related concussion head injury and injuries to other body regions were defined as those that received medical assessment or resulted in a missed match.ResultsThere were 20 teams monitored over 258 matches. 204 players (2484 player hours) wore mandated headgear throughout the season and 196 (2246 player hours) did not. The incidence rate of suspected sports-related concussion was 3.17 (95% confidence interval: 3.04–3.30) per 1000 player-hours and no differences were observed between males and females (risk ratio 1.11; 95% confidence interval: 0.40–3.06). Headgear use was not associated with suspected sports-related concussion (risk ratio 1.09; 95% confidence interval: 0.41–2.97), non-sports-related concussion head injury (risk ratio 0.27; 95% confidence interval: 0.06–1.31), or injuries to other body regions (risk ratio 1.41; 95% confidence interval: 0.79–2.53).ConclusionsHeadgear use was not associated with reduced risk of suspected sports-related concussion, non-sports-related concussion head injury or injuries to other body regions. There was no difference in the rate of suspected sports-related concussion in female compared to male players, however, rates of non-sports-related concussion head injury and injuries to other body regions were higher in male players.     

Injury history as a risk factor for incident injury in youth soccer

Objectives: To determine if athletes with a self reported history of previous injury have a higher incident injury rate than athletes without a self reported injury history.

Methods: A prospective cohort study of Classic League soccer players playing at the level under 12 through under 18. Injury history forms were mailed to all registering Classic League soccer players in the North Carolina Youth Soccer Association during 1997–2000 (n = 7000); 1483 (19%) returned the baseline questionnaire and were followed up for injuries.

Results: There were 5139 player-seasons of follow up and an estimated 171 957 athlete-exposures. More than half self reported an injury history (59.7%). Overall, the unadjusted incidence rate was 4.6 (95% confidence interval (CI) 4.3 to 4.9) incident injuries per 1000 athlete-exposures. Multivariate generalised Poisson regression modelling indicated that players with one previous injury had a twofold greater risk of incident injury (IRR = 2.6; 95% CI 2.0 to 3.3), and those with two or more previous injuries had a threefold greater risk of incident injury (IRR = 3.0; 95% CI 2.3 to 3.8) compared with athletes with no previous injuries.

Conclusions: Injury history was associated with an increased injury rate. This suggests that, even in these youth soccer players, those with an injury history may be at higher risk.

     

The relationship between fast bowling workload and injury in first-class cricketers: a pilot study

This study examined the relationship between the bowling workload of first-class fast bowlers and injury with the aim of identifying a "safe" fast bowling workload threshold. Twelve male fast bowlers (mean age 25 years) from an Australian state cricket squad were observed for the 1999--2000 cricket season. Workload was quantified by examining fixture scorecards and conducting surveillance at training sessions. Injury data were obtained from Cricket Australia's Injury Surveillance System. The seasonal incidence of injury was high with seven bowlers sustaining nine injuries. Whilst injured bowlers did not tend to bowl a greater number of deliveries on the day of injury, a significant increase in deliveries per session was observed in the 8-21 days prior to the date of injury (mean= 77) as compared with the rest of the season (mean= 60, p< 0.02). Bowlers with a weekly bowling workload above the mean of 203 deliveries were at an increased risk of injury (Risk Ratio (RR)= 6.0, 95% confidence interval (CI) 1.00-35.91). Those bowlers who bowled in five or more sessions in any 7-day period were also at an increased risk of injury (RR= 4.5, 95% CI 1.02 to 20.12). A consistent relationship between high bowling workload and injury was observed. The risk of injury was much higher for those bowlers with a sessional, weekly and monthly bowling workload above the group mean, especially when this high workload was consistent and sustained.     

Female soccer knee injury: Observed knowledge gaps in injury prevention among players/parents/coaches and current evidence (the KNOW study)

This study sought to determine if knowledge regarding the risk for knee injuries and the potential for their prevention is being translated to female adolescent soccer players (13–18 years), their parents, and coaches. Eligible participants in the 2007 indoor soccer season were surveyed to determine their knowledge of the risk for and the potential to prevent knee injuries, and their knowledge of effective prevention strategies, if they felt that injury prevention was possible. Team selection was stratified to be representative of both competitive and recreational level play and age group distributions within the selected soccer association. Of the study subjects, 773/1396 (55.4%) responded to the survey: 408 (53%) players, 292 (38%) parents, and 73 (9%) coaches. Most respondents (538 [71%]) were aware of the risk for knee injury. Coaches and parents were more likely than players to view knee injuries as preventable; however, appropriate prevention strategies were often not identified. Four hundred eighty‐four (63.8%) respondents reported that they had never received information on knee injuries. Substantial knowledge gaps regarding knee injury prevention and effective preventative strategies were identified. Given the predominance of knee injuries in female adolescent soccer players, there is an urgent need for knowledge translation of prevention strategies to decrease both incidence and long‐term consequences of knee injuries.     

A prevention strategy to reduce the incidence of injury in high school basketball: a cluster randomized controlled trial.

OBJECTIVE: To examine the effectiveness of a sport-specific balance training program in reducing injury in adolescent basketball. DESIGN: Cluster randomized controlled trial. SETTING: Twenty-five high schools in Calgary and surrounding area. SUBJECTS: Nine hundred and twenty high school basketball players (ages 12-18). INTERVENTION: Subjects were randomly allocated by school to the control (n = 426) and training group (n = 494). Both groups were taught a standardized warm-up program. The training group was also taught an additional warm-up component and a home-based balance training program using a wobble board. MAIN OUTCOME MEASURES: All injuries occurring during basketball that required medical attention and/or caused a player to be removed from that current session and/or miss a subsequent session were then recorded and assessed by a team therapist who was blinded to training group allocation. RESULTS: A basketball-specific balance training program was protective of acute-onset injuries in high school basketball [RR = 0.71 (95% CI; 0.5-0.99)]. The protective effect found with respect to all injury [RR = 0.8 (95% CI; 0.57-1.11)], lower-extremity injury [RR = 0.83 (95% CI; 0.57-1.19)], and ankle sprain injury [RR = 0.71 (95% CI; 0.45-1.13)] were not statistically significant. Self-reported compliance to the intended home-based training program was poor (298/494 or 60.3%). CONCLUSIONS: A basketball-specific balance training program was effective in reducing acute-onset injuries in high school basketball. There was also a clinically relevant trend found with respect to the reduction of all, lower-extremity, and ankle sprain injury. Future research should include further development of neuromuscular prevention strategies in addition to further evaluation of methods to increase compliance to an injury-prevention training program in adolescents.     

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.     

Incidence, causes, and severity of high school football injuries on FieldTurf versus natural grass: a 5-year prospective study

BACKGROUND: Numerous injuries have been attributed to playing on artificial turf. Recently, FieldTurf was developed to duplicate the playing characteristics of natural grass. No long-term study has been conducted comparing game-related, high school football injuries between the 2 playing surfaces. HYPOTHESIS: High school athletes would not experience any difference in the incidence, causes, and severity of game-related injuries between FieldTurf and natural grass. STUDY DESIGN: Prospective cohort study. METHODS: A total of 8 high schools were evaluated over 5 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism, primary type of injury, grade and anatomical location of injury, type of tissue injured, head and knee trauma, and environmental factors. RESULTS: Findings per 10 team games indicated total injury incidence rates of 15.2 (95% confidence interval, 13.7-16.4) versus 13.9 (95% confidence interval, 11.9-15.6). Minor injury incidence rates of 12.1 (95% confidence interval, 10.5-13.6) versus 10.7 (95% confidence interval, 8.7-12.7), substantial injury incidence rates of 1.9 (95% confidence interval, 1.4-2.6) versus 1.3 (95% confidence interval, 0.8-2.1), and severe injury incidence rates of 1.1 (95% confidence interval, 0.7-1.7) versus 1.9 (95% confidence interval 1.2-2.8) were documented on FieldTurf versus natural grass, respectively. Multivariate analyses indicated significant playing surface effects by injury time loss, injury mechanism, anatomical location of injury, and type of tissue injured. Higher incidences of 0-day time loss injuries, noncontact injuries, surface/epidermal injuries, muscle-related trauma, and injuries during higher temperatures were reported on FieldTurf. Higher incidences of 1- to 2-day time loss injuries, 22+ days time loss injuries, head and neural trauma, and ligament injuries were reported on natural grass. CONCLUSIONS: Although similarities existed between FieldTurf and natural grass over a 5-year period of competitive play, both surfaces also exhibited unique injury patterns that warrant further investigation.     

Bowling workload and the risk of injury in elite cricket fast bowlers.

This study examined the relationship between the bowling workload of first-class cricket fast bowlers and injury with the aim of identifying a workload threshold at which point the risk of injury increases. Ninety male fast bowlers (mean age 27 years, range 18-38 years) from six Australian state squads were observed for the 2000-2001 and/or 2001-2002 cricket seasons. Workload was quantified by examining fixture scorecards and conducting surveillance at training sessions. Injury data was obtained from the Cricket Australia's Injury Surveillance System. Compared to bowlers with an average of 3-3.99 days between bowling sessions, bowlers with an average of less than 2 days (risk ratio (RR) = 2.4, 95% confidence interval (CI) 1.6 to 3.5) or 5 or more days between sessions (RR = 1.8, 95% CI 1.1 to 2.9) were at a significantly increased risk of injury. Compared to those bowlers with an average of 123-188 deliveries per week, bowlers with an average of fewer than 123 deliveries per week (RR = 1.4, 95% CI 1.0 to 2.0) or more than 188 deliveries per week (RR= 1.4, 95% CI 0.9 to 1.6) may also be at an increased risk of injury. There appears to be a dual fast bowling workload threshold beyond which the risk of injury increases and maintaining a workload that is too low or infrequent is an equally significant risk factor for injury as maintaining a high bowling workload. Further study is required to determine the reason why players who bowl infrequently suffer more injuries.     

Ankle injuries in basketball: injury rate and risk factors

OBJECTIVES: To determine the rate of ankle injury and examine risk factors of ankle injuries in mainly recreational basketball players. METHODS: Injury observers sat courtside to determine the occurrence of ankle injuries in basketball. Ankle injured players and a group of non-injured basketball players completed a questionnaire. RESULTS: A total of 10 393 basketball participations were observed and 40 ankle injuries documented. A group of non-injured players formed the control group (n = 360). The rate of ankle injury was 3.85 per 1000 participations, with almost half (45.9%) missing one week or more of competition and the most common mechanism being landing (45%). Over half (56.8%) of the ankle injured basketball players did not seek professional treatment. Three risk factors for ankle injury were identified: (1) players with a history of ankle injury were almost five times more likely to sustain an ankle injury (odds ratio (OR) 4.94, 95% confidence interval (CI) 1.95 to 12.48); (2) players wearing shoes with air cells in the heel were 4.3 times more likely to injure an ankle than those wearing shoes without air cells (OR 4.34, 95% CI 1.51 to 12.40); (3) players who did not stretch before the game were 2.6 times more likely to injure an ankle than players who did (OR 2.62, 95% CI 1.01 to 6.34). There was also a trend toward ankle tape decreasing the risk of ankle injury in players with a history of ankle injury (p = 0.06). CONCLUSIONS: Ankle injuries occurred at a rate of 3.85 per 1000 participations. The three identified risk factors, and landing, should all be considered when preventive strategies for ankle injuries in basketball are being formulated.     

Self‐reported previous knee injury and low knee function increase knee injury risk in adolescent female football

Knee injuries are common in adolescent female football. Self‐reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to investigate self‐reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15–18, without knee injury at baseline, were included. Data on self‐reported previous knee injury and KOOS questionnaires were collected at baseline. Time‐loss knee injuries and football exposures were reported weekly by answers to standardized text‐message questions, followed by injury telephone interviews. A priori, self‐reported previous knee injury and low KOOS subscale scores (< 80 points) were chosen as independent variables in the risk factor analyses. The study showed that self‐reported previous knee injury significantly increased the risk of time‐loss knee injury [relative risk (RR): 3.65, 95% confidence (CI) 1.73–7.68; P < 0.001]. Risk of time‐loss knee injury was also significantly increased in players with low KOOS subscale scores (< 80 points) in Activities of Daily Living (RR: 5.0), Sport/Recreational (RR: 2.2) and Quality of Life (RR: 3.0) (P < 0.05). In conclusion, self‐reported previous knee injury and low scores in three KOOS subscales significantly increase the risk of future time‐loss knee injury in adolescent female football.     

Interaction of potential intrinsic and extrinsic risk factors in ACL injured recreational female skiers

The aim of this study was to investigate the interaction of potential intrinsic and extrinsic risk factors in ACL injured recreational female skiers. 93 female recreational skiers who had suffered a non-contact ACL injury and 93 age-matched controls completed a self-reported questionnaire relating to intrinsic risk factors (menstrual history, BMI, previous knee injuries, self reported weekly sports participation) and extrinsic risk factors (type of ski used, time of last binding adjustment, snow condition, weather and slope difficulty). A logistic regression model revealed the following independent ACL injury risk factors for female recreational skiers: icy snow conditions (odds ratio, 24.33; 95% confidence interval, 6.8-86.5, P<0.001), skiing during snowfall (odds ratio, 16.63; 95% confidence interval, 1.8-152.1, P=0.013), use of traditional skis (odds ratio, 10.49; 95% confidence interval, 2.0-54.5, P=0.005), and preovulatory phase of menstrual cycle (odds ratio, 2.59; 95% confidence interval, 1.2-5.5, P=0.013). In conclusion, ACL injuries in female recreational skiers are the result of a complex interaction of intrinsic and extrinsic risk factors.