Injuries in women's professional soccer

Does individual-specific strength training have an effect upon knee muscle strength balances? Knee muscle strength balances

OBJECTIVES

The purpose of the study was to investigate the effect of 8-week individual-specific strength exercises on knee muscle strength balance.

METHODS

Totally 42 male voluntary amateur soccer players participated in the study. The players were categorized into 3 groups with 14 members in each one; the control group (CG), maximal strength training group (STG) and individual-specific strength training group (ISTG). The players in both STG and ISTG performed strength exercises for lower extremity for 3 days per week for 8 weeks. Dominant (D) and non-dominant (ND) leg concentric extension and concentric flexion of the players were determined by means of isokinetic dynamometer called 'Biodex' at 60°s^-1, 180°s^-1 and 300°s^-1 angular velocities. Wilcoxon test was conducted to determine the differences between pre-test and post-test of the groups.

RESULTS

Dominant and non-dominant leg H/Q ratio was specified to increase in ISTG at 60°s^-1, 180°s^-1 and 300°s^-1 angular velocities (p<0.05). Although no statistically significant difference was found in terms of bilateral deficit in any groups, BLD was noticed to decrease significantly in dominant and non-dominant legs in ISTG group.

CONCLUSIONS

As a result, it was determined that in STG and ISTG considering the strength deficits of the athletes was to increase the H/Q ratio and reduce BLD, yet the H/Q ratios and BLD yielded a better improvement in ISTG, and thus leading a more effective method in individual training.

'What's my risk of sustaining an ACL injury while playing football (soccer)?' A systematic review with meta-analysis

OBJECTIVE

To estimate the incidence proportion (IP) and incidence rate (IR) of ACL injury in football players.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

PubMed, CINAHL and SPORTDiscus electronic databases were searched from inception to 20 January 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDY

Studies that reported the total number of participants/population by sex, total number of ACL injuries by sex and total person-time by sex were included.

RESULTS

Twenty-eight studies were included. The IP and IR of ACL injury in female football players were 2.0% (95% CI 1.2% to 3.1%) and 2.0/10 000 athlete exposures (AEs) (95% CI 1.6 to 2.6; I²=91%) over a period of one season to 4 years. The IP and IR of ACL injury in male players were 3.5% (95% CI 0.7% to 8.2%) and 0.9/10 000 AEs (95% CI 0.7 to 1.1; I²=94%). Studies that evaluated matched cohorts of female and male players showed no difference in IP (relative risk=1.2; 95% CI 0.9 to 1.6; P=0.47) over a period of one season to 4 years. Women were at greater risk than men (incidence rate ratio (IRR)=2.2; 95% CI 1.6 to 3.1; I²=83%; P<0.001). When accounting for participation level, the difference in IR between women and men was greatest for intermediate players (IRR=2.9; 95% CI 2.4 to 3.6) compared with amateur (IRR=2.6; 95% CI 1.4 to 4.8) and elite (IRR=2.0; 95% CI 1.1 to 3.4) players.

SUMMARY/CONCLUSION

Overall, more men sustained ACL injury in football. There was no difference in the relative risk of ACL injury between female and male football players in a window that spanned one season to 4 years. The IR of ACL injury among women was 2.2 times higher than the IR of ACL injury among men. The reported sex disparity in ACL injury was independent of participation level.

Anterior cruciate ligament ruptures in German elite soccer players: Epidemiology, mechanisms, and return to play

BACKGROUND

Anterior cruciate ligament ruptures (ACLRs) are severe sports-related injuries with significant consequences for affected players and teams. This study aims to identify the epidemiology and injury-related lay-off after ACLR in professional male soccer players from the first-division German Bundesliga.

METHODS

Exposure times and incidence of anterior cruciate ligament ruptures were collected during 7.5 consecutive seasons using two media-based registers.

RESULTS

A total of 72 total ACLRs were registered in 66 different players with an incidence of 0.040 per 1000h of exposure (95% CI 0.009-0.12). On average there were 9.6 ACLRs per season and 0.53 per team and season. The mean age of players affected was 24 (standard deviation±3.6) years. The number of ACLRs recorded per season fluctuated during the period observed. Goalkeepers are significantly (P<0.05) less prone to suffer an ACLR compared to outfield players.

CONCLUSIONS

Understanding ACLR loading mechanisms, knowing risk factors for the injury and mean off time after ACLR are essential information for the coach, the medical staff, the elite soccer players, the insurance and team managers. Our results are in accordance with reports based on information from medical team staff. Therefore, our analysis of ACLR based on media sources may serve as an alternative for injury reports in elite soccer. The information of this study may be helpful for the medical staff taking care of professional soccer players and for orthopedic surgeons performing ACL reconstructions in this patient population.

National Athletic Trainers' Association Position Statement: Prevention of Anterior Cruciate Ligament Injury

OBJECTIVE

  To provide certified athletic trainers, physicians, and other health care and fitness professionals with recommendations based on current evidence regarding the prevention of noncontact and indirect-contact anterior cruciate ligament (ACL) injuries in athletes and physically active individuals.

BACKGROUND

  Preventing ACL injuries during sport and physical activity may dramatically decrease medical costs and long-term disability. Implementing ACL injury-prevention training programs may improve an individual's neuromuscular control and lower extremity biomechanics and thereby reduce the risk of injury. Recent evidence indicates that ACL injuries may be prevented through the use of multicomponent neuromuscular-training programs.

RECOMMENDATIONS

  Multicomponent injury-prevention training programs are recommended for reducing noncontact and indirect-contact ACL injuries and strongly recommended for reducing noncontact and indirect-contact knee injuries during physical activity. These programs are advocated for improving balance, lower extremity biomechanics, muscle activation, functional performance, strength, and power, as well as decreasing landing impact forces. A multicomponent injury-prevention training program should, at minimum, provide feedback on movement technique in at least 3 of the following exercise categories: strength, plyometrics, agility, balance, and flexibility. Further guidance on training dosage, intensity, and implementation recommendations is offered in this statement.

Fractures in German elite male soccer players

BACKGROUND

Aim of this retrospective cohort study was to identify fracture epidemiology and off times after different types of fractures in German male elite soccer players from the first division Bundesliga based on information from the public media.

METHODS

Exposure and fracture data over 7.5 consecutive seasons (2009/10 until the first half of 2016/17) were collected from two media-based register (transfermarkt.de® and kicker.de®).

RESULTS

Overall, 357 fractures from 290 different players were recorded with an incidence of 0.19/1000 hours of exposure (95% CI: 0.14-0.24). Most fractures in German elite soccer players involved the lower extremities (35.3%), the head/face (30.3%) and the upper extremities (24.9%). The median off time after a fracture in German elite male professional soccer in 7.5 Season was 51.1 days (range 0-144). The number of fractures per 100 players per season decreased between 2009 and 2016. There was no significant difference in overall fracture incidence when comparing players at different position (P=0.11). Goalkeepers have a significantly (P<0.02) higher likelihood of suffering hand and finger fractures and they are significantly (P<0.03) less prone of suffering foot fractures, cranial and maxillofacial fractures (P<0.04). compared to outfield players.

CONCLUSIONS

This study can confirm that male professional soccer teams experience 1-2 fractures per season in German elite soccer. The incidence of fractures in elite German soccer players decreased between 2009 and 2016. The most fractures occur in the lower extremities and there is no difference in overall fracture risk for players at different playing positions. The information from our study might be of a great importance to medical practitioners, soccer coaches and soccer manager.

Does the FIFA 11+ Injury Prevention Program Reduce the Incidence of ACL Injury in Male Soccer Players?

BACKGROUND

The FIFA 11+ injury prevention program has been shown to decrease the risk of soccer injuries in men and women. The program has also been shown to decrease time loss resulting from injury. However, previous studies have not specifically investigated how the program might impact the rate of anterior cruciate ligament (ACL) injury in male soccer players.

QUESTIONS/PURPOSES

The purpose of this study was to examine if the FIFA 11+ injury prevention program can (1) reduce the overall number of ACL injuries in men who play competitive college soccer and whether any potential reduction in rate of ACL injuries differed based on (2) game versus practice setting; (3) player position; (4) level of play (Division I or II); or (5) field type.

METHODS

This study was a prospective cluster randomized controlled trial, which was conducted in 61 Division I and Division II National Collegiate Athletic Association men's soccer teams over the course of one competitive soccer season. The FIFA 11+ is a 15- to 20-minute on-the-field dynamic warm-up program used before training and games and was utilized as the intervention throughout the entire competitive season. Sixty-five teams were randomized: 34 to the control group (850 players) and 31 to the intervention group (675 players). Four intervention teams did not complete the study and did not submit their data, noting insufficient time to complete the program, reducing the number for per-protocol analysis to 61. Compliance to the FIFA 11+ program, athletic exposures, specific injuries, ACL injuries, and time loss resulting from injury were collected and recorded using a secure Internet-based system. At the end of the season, the data in the injury surveillance system were crosshatched with each individual institution's internal database. At that time, the certified athletic trainer signed off on the injury collection data to confirm their accuracy and completeness.

RESULTS

A lower proportion of athletes in the intervention group experienced knee injuries (25% [34 of 136]) compared with the control group (75% [102 of 136]; relative risk [RR], 0.42; 95% confidence interval [CI], 0.29-0.61; p < 0.001). When the data were stratified for ACL injury, fewer ACL injuries were reported in the intervention group (16% [three of 19]) compared with the control group (84% [16 of 19]), accounting for a 4.25-fold reduction in the likelihood of incurring ACL injury (RR, 0.236; 95% CI, 0.193-0.93; number needed to treat = 70; p < 0.001). With the numbers available, there was no difference between the ACL injury rate within the FIFA 11+ group and the control group with respect to game and practice sessions (games-intervention: 1.055% [three of 15] versus control: 1.80% [12 of 15]; RR, 0.31; 95% CI, 0.09-1.11; p = 0.073 and practices-intervention: 0% [zero of four] versus control: 0.60% [four of four]; RR, 0.14; 95% CI, 0.01-2.59; p = 0.186). With the data that were available, there were no differences in incidence rate (IR) or injury by player position for forwards (IR control = 0.339 versus IR intervention = 0), midfielders (IR control = 0.54 versus IR intervention = 0.227), defenders (IR control = 0.339 versus IR intervention = 0.085), and goalkeepers (IR control = 0.0 versus IR intervention = 0.0) (p = 0.327). There were no differences in the number of ACL injuries for the Division I intervention group (0.70% [two of nine]) compared with the control group (1.05% [seven of nine]; RR, 0.30; CI, 0.06-1.45; p = 0.136). However, there were fewer ACL injuries incurred in the Division II intervention group (0.35% [one of 10]) compared with the control group (1.35% [nine of 10]; RR, 0.12; CI, 0.02-0.93; p = 0.042). There was no difference between the number of ACL injuries in the control group versus in the intervention group that occurred on grass versus turf (Wald chi square [1] = 0.473, b = 0.147, SE = 0.21, p = 0.492). However, there were more ACL injuries that occurred on artificial turf identified in the control group (1.35% [nine of 10]) versus the intervention group (0.35% [one of 10]; RR, 0.14; 95% CI, 0.02-1.10; p = 0.049).

CONCLUSIONS

This program, if implemented correctly, has the potential to decrease the rate of ACL injury in competitive soccer players. In addition, this may also enhance the development and dissemination of injury prevention protocols and may mitigate risk to athletes who utilize the program consistently. Further studies are necessary to analyze the cost-effectiveness of the program implementation and to analyze the efficacy of the FIFA 11+ in the female collegiate soccer cohort.

LEVEL OF EVIDENCE

Level I, therapeutic study.

High prevalence of self-reported injuries and illnesses in talented female athletes

Background

A thorough knowledge of the epidemiology and severity of injuries and illness in youth female elite sports is lacking due to the methodological challenges involved in recording them. In this study, the prevalence and incidence of injuries and illness are assessed among youth female elite athletes. Instead of solely focusing on time-loss injuries, our study included all substantial and non-substantial health problems (ie, injuries, mental problems and illnesses).

Methods

Sixty young elite Dutch female athletes (age: 16.6 years (SD: 2.3), weight: 58.3 kg (SD: 15.1), height: 154.1 cm (SD: 44.2)) participating in soccer (n=23), basketball (n=22) and gymnastic (n=15) talent development programmes were prospectively followed during one season (September 2014 to April 2015). To collect health problem data, all athletes completed the Oslo Sports Trauma Research Center Questionnaire on Health Problems every other week. Main outcome measures were average prevalence of injury and incidence density of injury.

Results

At any given time, 47.9% of the athletes reported an injury (95% CI 43.6% to 52.6%) and 9.1% reported an illness (95% CI 5.1 to 19.0). The average injury incidence density was 8.6 per 1000 hours of athlete exposure. The average number of self-reported injuries per athlete per season was significantly higher in soccer athletes (4.3±2.7) than in basketball athletes (2.6±2.0) (p=0.03) and not significantly higher than in the gymnastic squad. The knee and the ankle were two of the most common injury locations for all squads. Knee injuries in basketball and soccer and heel injuries in the gymnastic squad had the highest impact on sports participation.

Conclusion

High prevalence of self-reported injuries among talented female athletes suggests that future efforts towards their prevention are warranted.

Epidemiology of Knee Sprains in Youth, High School, and Collegiate American Football Players

CONTEXT

  Variations in knee-sprain incidence among competition levels are unclear but may help inform prevention strategies in American football players.

OBJECTIVE

  To describe the epidemiology of knee sprains in youth, high school, and collegiate football players.

DESIGN

  Descriptive epidemiology study.

SETTING

  Injury and athlete-exposure (AE) data were collected from 3 injury-surveillance programs at the youth, high school, and collegiate competition levels.

PATIENTS OR OTHER PARTICIPANTS

  Data from 310 youth, 184 high school, and 71 collegiate football team-seasons were collected during the 2012 through 2014 seasons.

MAIN OUTCOME MEASURE(S)

  Knee-sprain rates and risks were calculated for each competition level. Injury rate ratios (IRRs) and risk ratios (RRs) compared knee-sprain rates by competition level. Injury proportion ratios (IPRs) compared differences in surgery needs, recurrence, injury mechanism, and injury activity by competition level.

RESULTS

  Knee-sprain rates in youth, high school, and collegiate football were 0.16/1000 AEs, 0.25/1000 AEs, and 0.69/1000 AEs, respectively. Knee-sprain rates increased as the competition level increased (high school versus youth: IRR = 1.60; 95% confidence interval [CI] = 1.12, 2.30; collegiate versus high school: IRR = 2.73; 95% CI = 2.38, 3.96). Knee-sprain risk was highest in collegiate (4.3%), followed by high school (2.0%) and youth (0.5%) athletes. Knee-sprain risk increased as the competition level increased (high school versus youth: RR = 3.73; 95% CI = 2.60, 5.34; collegiate versus high school: RR = 2.14; 95% CI = 1.83, 2.51). Collegiate football had the lowest proportion of knee sprains that were noncontact injuries (collegiate versus youth: IPR = 0.54; 95% CI = 0.31, 0.95; collegiate versus high school: IPR = 0.59; 95% CI = 0.44, 0.79) and the lowest proportion that occurred while being tackled (collegiate versus youth: IPR = 0.44; 95% CI = 0.26, 0.76; collegiate versus high school: IPR = 0.71; 95% CI = 0.51, 0.98).

CONCLUSIONS

  Knee-sprain incidence was highest in collegiate football. However, level-specific variations in the distributions of knee sprains by injury activity may highlight the need to develop level-specific policies and prevention strategies that ensure safe sports play.

A comparison of injuries in elite male and female football players: A five-season prospective study

The aim was to compare the epidemiology of injuries between elite male and female football players from the same club. Injuries and individual exposure time in a male team and a female team, both playing in the Spanish first division, were prospectively recorded by the club's medical staff for five seasons (2010-2015) following the FIFA consensus statement. Total, training, and match exposure hours per player-season were 20% higher for men compared to women (P<.01). Total, training, and match injury incidence were 30%-40% higher in men (P≤.04) mainly due to a 4.82 (95% confidence interval [CI] 2.30-10.08) times higher incidence of contusions, as there were no differences in the incidence of muscle and joint/ligament injuries (P≥.44). The total number of absence days was 21% larger in women owing to a 5.36 (95% CI 1.11-25.79) times higher incidence of severe knee and ankle ligament injuries. Hamstring strains and pubalgia cases were 1.93 (95% CI 1.16-3.20) and 11.10 (95% CI 1.48-83.44) times more frequent in men, respectively; whereas quadriceps strains, anterior cruciate ligament ruptures, and ankle syndesmosis injuries were 2.25 (95% CI 1.22-4.17), 4.59 (95% CI 0.93-22.76), and 5.36 (95% CI 1.11-25.79) times more common in women, respectively. In conclusion, prevention strategies should be tailored to the needs of male and female football players, with men more predisposed to hamstring strains and hip/groin injuries, and women to quadriceps strains and severe knee and ankle ligament injuries.

Incidence, Mechanisms, and Severity of Match-Related Collegiate Men's Soccer Injuries on FieldTurf and Natural Grass Surfaces: A 6-Year Prospective Study

BACKGROUND

Numerous injuries have been attributed to playing on artificial turf. More recently, newer generations of artificial turf have been developed to duplicate the playing characteristics of natural grass. Although artificial turf has been deemed safer than natural grass in some studies, few long-term studies have been conducted comparing match-related collegiate soccer injuries between the 2 playing surfaces.

HYPOTHESIS

Collegiate male soccer athletes do not experience any difference in the incidence, mechanisms, or severity of match-related injuries between FieldTurf and natural grass.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Male soccer athletes from 11 universities were evaluated over 6 seasons. Demographic features and predictors included player position, cleat design, player weight, turf age, and environmental factors. Outcomes of interest included injury incidence, injury category, time loss, injury mechanism and situation, type of injury, injury grade and anatomic location, injury severity, head and lower extremity trauma, and elective medical procedures. All match-related injuries were evaluated by the attending head athletic trainer and team physicians on site and subsequently in the physician's office when further follow-up and treatment were deemed necessary. In sum, 765 collegiate games were evaluated for match-related soccer injuries sustained on FieldTurf or natural grass during 6 seasons.

RESULTS

Overall, 380 team games (49.7%) were played on FieldTurf versus 385 team games (50.3%) played on natural grass. A total of 722 injuries were documented, with 268 (37.1%) occurring on FieldTurf and 454 (62.9%) on natural grass. Multivariate analysis per 10 team games indicated a significant playing surface effect: F_2,720 = 7.260, P = .001. A significantly lower total injury incidence rate (IIR) of 7.1 (95% CI, 6.6-7.5) versus 11.8 (95% CI, 11.3-12.2; P < .0001) and lower rate of substantial injuries, 0.7 (95% CI, 0.5-1.0) versus 1.9 (95% CI, 1.5-2.3; P < .03), were documented on FieldTurf versus natural grass, respectively. Analyses also indicated significantly less trauma on FieldTurf when comparing injury category, time loss, player position, injury mechanism and situation, injuries under various environmental conditions, cleat design, turf age, anatomic location, and elective medical procedures. No significant difference (F_11,710 = 0.822, P = .618) between surfaces by knee injury was observed, with the majority of knee injuries involving patellar tendinopathies/syndromes followed by medial collateral ligament injuries on both surfaces.

CONCLUSION

Although similarities existed between FieldTurf and natural grass during competitive match play, FieldTurf is, in many cases, safer than natural grass when comparing injuries in collegiate men's soccer. The findings of this study, however, may not be generalizable to other levels of competition or to other artificial surfaces.

Risk factors of anterior cruciate ligament injury in football players: a systematic review of the literature

BACKGROUND

The ACL lesion represents one of the most dramatic injuries in a sportsman's career. There are many injury risk factors related to intrinsic, or non-modifiable, and extrinsic, or modifiable, factors. In literature at today current evidence suggests that ACL injury risk is multifactorial and involves biomechanical, anatomical, hormonal and neuromuscular factors.

PURPOSE

To perform a systematic review of the literature concerning the ACL injury risk factors in soccer.

CONCLUSION

The injury risk factors show a low level of evidence, further studies in the field are needed.

STUDY DESIGN

Systematic review.

Injury Profile in Swedish Elite Floorball

BACKGROUND

Floorball is an indoor team sport with growing popularity worldwide characterized by rapid accelerations, decelerations, and cutting and pivoting movements. While injuries are common, there are few high-quality epidemiological investigations of floorball injuries. Therefore, the aim of this study was to determine the incidence and severity of injuries in male and female elite-level floorball players in Sweden.

HYPOTHESIS

The incidence of injuries has not decreased; female players are more vulnerable to injury than male players.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Twelve floorball teams (6 male, 6 female) in the Swedish premiere leagues were followed for 1 year (preseason, game season, and the entire year). The team medical staff reported injury incidence, location, type (traumatic or overuse), and severity. Differences between male and female players were analyzed using the Mann-Whitney U test.

RESULTS

The injury incidence was greater in female players during preseason (22.9 vs 7.4, P = 0.01), game season (39.5 vs 28.3, P = 0.002), as well as the whole year combined (33.9 vs 20.8, P = 0.02). The thigh was the most common injury location in male players and the ankle in female players. Overuse injuries were more common among men and were primarily back problems. Traumatic injuries were more common in women-mainly knee and ankle injuries. Most injuries were of mild severity. A greater number of anterior cruciate ligament injuries occurred in women (n = 11) than in men (n = 2).

CONCLUSION

The injury incidence was significantly greater in female floorball players throughout the entire floorball year. Male players sustained mostly overuse injuries while female players suffered traumatic injuries. The majority of injuries in floorball were mild, irrespective of player sex.

CLINICAL RELEVANCE

Knowledge of the incidence and severity of floorball injuries is an essential step in the sequence of injury prevention. Future research should focus on identifying injury mechanisms and risk factors for these injuries to develop injury prevention strategies.

Trauma injuries sustained by female footballers

Soccer is becoming the leading sport for women worldwide with 21 million females registered with the Federation Internationale de Football Association (FIFA). It is now the top female sport in England with 131 678 registered players and 9600 registered clubs. Several studies have looked at the injury rates amongst female players. Some injuries have been highlighted as more common in women. This article looks at the epidemiology of injuries in women's soccer and in particular anterior cruciate ligament injuries, ankle injuries and concussion. It will discuss the diagnosis and management needed for these injuries in female soccer players. With this increasing popularity, clinicians will see more female players sustaining trauma through playing soccer. Early and appropriate management of these injuries is essential if women are to continue to enjoy soccer at a recreational level and succeed at a competitive level, perhaps with a podium finish in 2012.

Risk factors for acute knee injury in female youth football

PURPOSE

To prospectively evaluate risk factors for acute time-loss knee injury, in particular ACL injury, in female youth football players.

METHODS

Risk factors were studied in 4556 players aged 12-17 years from a randomised controlled trial during the 2009 season. Covariates were both intrinsic (body mass index, age, relative age effect, onset of menarche, previous acute knee injury or ACL injury, current knee complaints, and familial disposition of ACL injury) and extrinsic (no. of training sessions/week, no. of matches/week, match exposure ratio, match play with other teams, and artificial turf exposure). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated from individual variable and multiple Cox regression analyses.

RESULTS

Ninety-six acute knee injuries were recorded, 21 of them ACL injuries. Multiple Cox regression showed a fourfold higher ACL injury rate for players with familial disposition of ACL injury (HR 3.57; 95% CI 1.48-8.62). Significant predictor variables for acute knee injury were age >14 years (HR 1.97; 95% CI 1.30-2.97), knee complaints at the start of the season (HR 1.98; 95% CI 1.30-3.02), and familial disposition of ACL injury (HR 1.96; 95% CI 1.22-3.16). No differences in injury rates were seen when playing on artificial turf compared with natural grass.

CONCLUSION

Female youth football players with a familial disposition of ACL injury had an increased risk of ACL injury and acute knee injury. Older players and those with knee complaints at pre-season were more at risk of acute knee injury. Although the predictive values were low, these factors could be used in athlete screening to target preventive interventions.

LEVEL OF EVIDENCE

II.

ACL injury in football: a literature overview of the prevention programs

BACKGROUND

The ACL prevention programs are addressed to the control and/or modification of the so-called "modifiable risk factors". All these programs focus on different intervention strategies aimed to decrease the ACL injury risk, particularly in female athletes population.

PURPOSE

To furnish an overview of the most used ACL injury prevention program through a narrative review.

CONCLUSION

In literature there are many reports on prevention programs whose common denominator is the proper alignment of the lower limb joints and proper motor control during movements that are considered at risk for ACL integrity, as the landing phase after a jump. Nevertheless, some programs would appear more effective than others. In any cases a major problem remains the lack of sufficient compliance in respect of prevention programs. Finally, it is important to remember that the ethiology of ACL injuries is multifactorial. For this reason a prevention program able to prevent all the risk situations is utopian.

STUDY DESIGN

Narrative review.

Incidence of Patients With Knee Strain and Sprain Occurring at Sports or Recreation Venues and Presenting to United States Emergency Departments

CONTEXT

Knee injuries account for a substantial percentage of all athletic injuries. The relative rates of knee injury for a variety of sports by sex and age need to be understood so we can better allocate resources, such as athletic trainers, to properly assess and treat injuries and reduce injury risk.

OBJECTIVE

To describe the epidemiology of patients with sport-related knee strain and sprain presenting to US emergency departments from 2002 to 2011.

DESIGN

Cross-sectional study.

SETTING

Using the Consumer Products Safety Commission's National Electronic Injury Surveillance System and the US Census Bureau, we extracted raw data to estimate national rates of patients with knee strain and sprain presenting to emergency departments.

PATIENTS OR OTHER PARTICIPANTS

Participants were individuals sustaining a knee strain or sprain at sports or recreation venues and presenting to local emergency departments for treatment. We included 12 popular sports for males and 11 for females. Ages were categorized in six 5-year increments for ages 5 to 34 years and one 10-year increment for ages 35 to 44 years.

MAIN OUTCOME MEASURE(S)

Incidence rates were calculated using weights provided by the National Electronic Injury Surveillance System and reported with their 95% confidence intervals for sport, sex, and age.

RESULTS

Strain and sprain injury rates varied greatly by sport, sex, and age group. The highest injury rates occurred in football and basketball for males and in soccer and basketball for females. The most at-risk population was 15 to 19 years for both sexes.

CONCLUSIONS

Athletes experience different rates of knee strain and sprain according to sport, sex, and age. Increased employment of athletic trainers to care for the highest-risk populations, aged 10 to 19 years, is recommended to reduce emergency department use and implement injury-prevention practices.

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.

Are Elite Female Soccer Athletes at Risk for Disordered Eating Attitudes, Menstrual Dysfunction, and Stress Fractures?

OBJECTIVE

To determine the prevalence of stress fractures, menstrual dysfunction and disordered eating attitudes in elite female soccer athletes.

DESIGN

Cross-sectional descriptive study.

SETTING

Female soccer athletes were recruited from a national level youth soccer club, an NCAA Division I university team, and a women's professional team.

PARTICIPANTS

Two hundred twenty female soccer athletes with a mean age of 16.4 ± 4 years and BMI of 20.8 ± 2 kg/m(2) completed the study, representing all athletes from the included teams.

METHODS

One-time surveys completed by the athletes.

MAIN OUTCOME MEASUREMENTS

Height and weight were recorded, and body mass index (BMI) was calculated for each athlete. Athletes reported age of menarche, history of missing 3 or more menses within a 12-month period and stress fracture. The Eating Attitudes Test (EAT-26) was used to assess the athlete's body perception and attitudes toward eating.

RESULTS

Of the 220 soccer athletes, 3 athletes (1.6%) had a low BMI for their age, and 19 (8.6%) reported stress fractures of the lower extremity. Among athletes who had reached menarche, the average onset was 13 + 1 year; menstrual dysfunction were present in 21 (19.3%). On the EAT-26, 1 player scored in the high risk range (>20) and 17 (7.7%) scored in the intermediate risk range (10-19) for eating disorders. Athletes with an EAT-26 score ≥ 10 points had a significantly higher prevalence of menstrual dysfunction in the past year compared to athletes with an EAT-26 score of less than 10 (P = .02).

CONCLUSIONS

Elite female soccer athletes are susceptible to stress fractures and menstrual dysfunction and have delayed onset of menarche despite normal BMI and appropriate body perception and attitudes towards eating. Further studies are needed to better understand stress fracture risk in female soccer athletes and in other team sports to determine how these findings relate to long-term bone health in this population.

The incidence of injury in a Caribbean amateur women's football league

This prospective study looked at the incidence of injury (IN) sustained by players during a season in an amateur women's football league in Trinidad and Tobago where games were played on grass (GR) and on a new generation artificial turf (AT). The overall incidence of time loss injuries was 27.6/1000 player hours (95% CI: 17.0, 38.2). Most injuries were mild and players returned to play within one week of sustaining an injury. Players who trained predominately on, and played their home games on AT (PAT) sustained significantly fewer injuries when playing games on GR than those sustained while playing on AT (p=0.006). There were no differences in injury rates between games played on AT versus games played on GR (p=0.68). Most injuries were of a non-contact nature and so an injury prevention program should be implemented to reduce the injury rate in this amateur league.

An interval kicking progression for return to soccer following lower extremity injury

BACKGROUND AND PURPOSE

The majority of all soccer injuries affect the lower extremities. Regardless of whether the injured limb is an athlete's preferred kicking or stance leg, a lower extremity injury may affect their ability to impact the ball. Sport-specific biomechanical progressions to augment loading and gradually reintroduce a player to the demands of sport have been developed for upper extremity sports such as baseball, softball, tennis, and golf. Generalized return to soccer progressions have also been published in order to assist clinicians in safely returning athletes to sport; however, there are no specific progressions for the early stages of kicking designed to introduce stance leg loading and kicking leg impact. Thus, the purpose of this clinical commentary was to review the existing literature elucidating the biomechanics of kicking a soccer ball and propose a progressive kicking program to support clinicians in safely returning their soccer athletes to the demands of sport.

DESCRIPTION OF TOPIC

The interval kicking program (IKP) describes clinical guidelines for readiness to begin a kicking program as well as possible readiness to return to sport measures. The program is performed on alternate days integrating therapeutic exercise and cardiovascular fitness. The IKP gradually introduces a player to the loading and impact of kicking. The progression increases kicking distance (using the markings of a soccer field as a guide), volume, and intensity and uses proposed soreness rules, effusion guidelines, and player feedback in order to assist clinicians in determining readiness for advancement though the stages. The IKP also recommends utility of specific tests and measures to determine readiness for return to sport.

DISCUSSION

Gradual reintroduction to sport specific demands is essential for a safe return to soccer. This return to sport progression provides a framework integrating injury specific therapeutic exercise, cardiovascular fitness, and the return to kicking progression, to assist clinicians in initiating an athletes' return to soccer.

LEVEL OF EVIDENCE

Level 5.

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.

The effectiveness of preventive programs in decreasing the risk of soccer injuries in Belgium: national trends over a decade

BACKGROUND

Although characterized by a relatively high injury rate, soccer is the world's most popular sport. In Belgium, the national Royal Belgian Football Association involves about 420,000 licensed players, whose injury reports are collected in a nationwide registry. Over a period of 10 years, the association has introduced the Fédération Internationale de Football Association preventive programs and has initiated a stringent postponement policy of competition in case of nonoptimal weather conditions.

HYPOTHESIS

The authors questioned whether these preventive programs effectively decreased the incidence of soccer-related injuries.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

The authors compared the incidence, location, timing, and severity of all registered soccer injuries in Belgium during 2 complete seasons separated by a decade (1999-2000 vs 2009-2010).

RESULTS

A total of 56,364 injuries were reported, with an average of 6.8 injuries per 100 players per season. There was a 21.1% reduction in injury rate in the second season (rate ratio = 0.789; 95% confidence interval, 0.776-0.802), predominantly caused by a significant reduction in injuries during the winter period. In both seasons, an injury peak was noted during the first 3 months of the season. Recreational players had a higher risk for injury than national-level players (7.2 vs 4.4 injuries per 100 players per season; rate ratio = 1.64; 95% confidence interval, 1.59-1.69). The relative proportion of severe injuries was higher for female players and male youth players in general.

CONCLUSION

The introduction of injury preventive programs has led to a significant reduction of soccer-related injuries, especially during the winter period. However, there is still room for improvement, and preventive programs can become more effective when specific parameters are targeted, such as adequate conditioning of players in the preseason.

Factors associated with injuries among first-division Rwandan female soccer players

BACKGROUND

Female soccer has grown tremendously in the last decade. Studies have suggested that female soccer players are more susceptible to injuries than their male counterparts, and their vulnerability is due mainly to intrinsic factors such as their anatomical and physiological structure.

OBJECTIVES

To establish factors associated with soccer injuries among first-division Rwandan female soccer players.

METHODS

In a descriptive cross-sectional study, self-administered questionnaires were used to investigate factors associated with injuries among soccer players.

RESULTS

Almost half of the 300 participants (45%) indicated having been injured in the three seasons prior to the study. More than half (52.6%) were recurrent injuries. The ankle was the most common body part injured. Intrinsic factors associated with injuries were age, excessive ankle range of motion, pre-menstrual symptoms, and previous injury (p-value < 0.05). Extrinsic factors associated with injuries were use of oral contraceptive pills, (OCP), competition level, use of protective equipment, and player's position.

CONCLUSIONS

The large number of recurring injuries was notable, emphasizing the importance of prevention strategies and access to adequately trained medical personnel as research has shown a significant reduction in the prevalence of recurring injuries after the introduction of effective prevention programmes.

Review of sport-induced groin injuries

CONTEXT

Groin injuries are among the most common injuries co-existing with sports. The aim of this review was to outline the epidemiology and identify risk factors, as well as examine preventative and interventional measures for reducing the occurrence of this form of injury among athletes.

EVIDENCE ACQUISITION

An electronic, systematic search for relevant keywords, either separately or in combination was sought in the academic scientific databases.

RESULTS

Groin injuries, acute or chronic, consist of a high percentage of injuries that manifest with pain. Despite the specific tendency for injury among some sports, such injuries make up 2-5% of sport-induced injuries. There are few available reports on lower limb injuries, especially groin injuries, in Iran. Numerous factors predispose to groin injuries. A lengthy list of preventive/ treatment measures, from preliminary to sophisticated, have been proposed.

CONCLUSIONS

Although using a programmed strategy designed to decrease the risk of groin injuries by taking a strategic approach to exercise may alleviate complications, in some cases the chronic nature of the injury may threaten the professional life of the athlete. More research is required to plan suitable programs for reducing the risk of this type of injury in athletes.

Incidence, mechanisms, and severity of match-related collegiate women's soccer injuries on FieldTurf and natural grass surfaces: a 5-year prospective study

BACKGROUND

Numerous injuries have been attributed to playing on artificial turf. Over the past 2 decades, however, newer generations of synthetic turf have been developed to duplicate the playing characteristics of natural grass. Although synthetic turf has been determined to be safer than natural grass in some studies, few long-term studies have been conducted comparing match-related collegiate soccer injuries between the 2 playing surfaces.

HYPOTHESIS

Collegiate female soccer athletes do not experience any difference in the incidence, mechanisms, and severity of match-related injuries on FieldTurf and on natural grass.

STUDY DESIGN

Cohort study: Level of evidence, 2.

METHODS

Female soccer athletes from 13 universities were evaluated over 5 competitive seasons for injury incidence, injury category, time of injury, injury time loss, player position, injury mechanism and situation, primary type of injury, injury grade and anatomic location, field location at the time of injury, injury severity, head and lower extremity trauma, cleat design, turf age, and environmental factors. In sum, 797 collegiate games were evaluated for match-related soccer injuries sustained on FieldTurf or natural grass during 5 seasons.

RESULTS

Overall, 355 team games (44.5%) were played on FieldTurf versus 442 team games (55.5%) on natural grass. A total of 693 injuries were documented, with 272 (39.2%) occurring during play on FieldTurf and 421 (60.8%) on natural grass. Multivariate analysis per 10 team games indicated a significant playing surface effect: F₂,₆₉₀ = 6.435, P = .002, n-β = .904. A significantly lower total injury incidence rate (IIR) of 7.7 (95% confidence interval [CI], 7.2-8.1) versus 9.5 (95% CI, 9.3-9.7) (P = .0001) and lower rate of substantial injuries, 0.7 (95% CI, 0.5-1.0) versus 1.5 (95% CI, 1.2-1.9) (P = .001), were documented on FieldTurf versus natural grass, respectively. Analyses also indicated significantly less trauma on FieldTurf when comparing injury time loss, player position, injury grade, injuries under various field conditions and temperatures, cleat design, and turf age.

CONCLUSION

Although similarities existed between FieldTurf and natural grass during competitive match play, FieldTurf is a practical alternative when comparing injuries in collegiate women's soccer. It must be reiterated that the findings of this study may be generalizable to only collegiate competition and this specific artificial surface.

Evaluation of functional limitations in female soccer players and their relationship with sports level--a cross sectional study

THE MAIN OBJECTIVES OF THE STUDY

the aim of this study was to analyze: a) abnormalities in the length of lower limb muscles, b) the correctness of movement patterns, and c) the impact of functional limitations of muscles on the correctness of fundamental movement patterns in a group of female soccer players, in relation to their skill level.

MATERIALS AND METHODS

21 female soccer players from Polish Ekstraklasa and 22 players from the 1(st) Division were tested for lower limb muscle length restrictions and level of fundamental movement skills (with the Fundamental Movement Screen™ test concept by Gray Cook). Chi-square test was used for categorical unrelated variables. Differences between groups in absolute point values were analyzed using the non-parametric Mann-Whitney U test. Statistical significance was set at p<0.05.

RESULTS

Statistically significant higher number of measurements indicating an abnormal length of rectus femoris was observed in the 1st Division group (p = 0.0433). In the group of Ekstraklasa the authors obtained a significantly higher number of abnormal hamstring test results (p = 0.0006). Ekstraklasa players scored higher in the rotational stability test of the trunk (p = 0.0008), whereas the 1st Division players scored higher in the following tests: deep squat (p = 0.0220), in-line lunge (p = 0.0042) and active straight leg raise (p = 0.0125). The results suggest that there are different functional reasons affecting point values obtained in the FMS™ tests in both analyzed groups.

CONCLUSIONS

The differences in the flexibility of rectus femoris and hamstring muscle observed between female soccer players with different levels of training, may result from a long-term impact of soccer training on the muscle-tendon system and articular structures. Different causes of abnormalities in fundamental movement patterns in both analyzed groups suggest the need for tailoring prevention programs to the level of sport skills represented by the players.

The health profile of professional soccer players: future opportunities for injury prevention

Injuries are a major adverse event during a soccer player's career; they require medical and surgical treatment and rehabilitation and thus may interrupt the player's activity, often with severe physical and psychological sequel. Specialists have tried to identify the risk factors for injuries, in an attempt to discover predictors that could be prevented and or eliminated before the injury occurs, but the results are scarce. This article reviews the epidemiology of the frequency and occurrence of injuries in Italian soccer players, reports a list of preventable risk factors that are associated with injuries, and identifies preventable risk factors. We have identified personal factors (age, previous traumatic events, physical and biological characteristics of the player, life style habits such as smoking, alcohol, and diet, changes in physical-athletic aspects of the players, such as increased muscle strength, and use of medications) as possible risk factors for injuries. However, environmental factors such as changes in training techniques, field composition, and shoes structure may also have a major influence. This summary indicates that appropriate preventive measures can be undertaken to prevent injuries in professional soccer players. Professionals who are in close contacts with the players should be informed of the predictors of injuries and should be trained to intervene and plan appropriate preventive measures.

The effects of a moderate exercise program on knee osteoarthritis in male wistar rats

OBJECTIVE(S)

Osteoarthritis (OA) or degenerative joint disease is the commonest form of arthritis and can lead to joint pain, decrease in joint's range of motion, loss of function, and ultimately disability. Exercise is considered as one of the non-pharmacological treatments of OA. But the effects of exercise on knee joint cartilage remain ambiguous. The aim of the present study was to investigate the effect of a four-week moderate treadmill exercise on rats' knee osteoarthritis.

MATERIALS AND METHODS

Eighteen male Wistar rats (173 ± 1 g, 8 weeks old) were randomly divided into three groups (n = 6): Intact control, monosodium iodoacetate (MIA) only (OA), and training. The osteoarthritis model was induced by intra-articular injection of monosodium iodoacetate (MIA). Subjects followed a moderate-intensity exercise program for 28 days. Rats were killed after 28 days and histological assessment was done on their knee joints. One-way ANOVA (P<0.05) and post-hoc Tukey test was used for the statistical analysis.

RESULTS

Histological assessment on 3 measurements of, depth ratio of lesions (P=0.001), total cartilage degeneration width (P=0.001), and significant cartilage degeneration width (P=0.001), demonstrated that moderate exercise for 4 weeks could surprisingly almost treat OA symptoms of rats' knee joints.

CONCLUSION

The findings of the present study indicate that a moderate treadmill exercise program exert a beneficial influence on rats' knee osteoarthritis.

Changes in lower extremity biomechanics due to a short-term fatigue protocol

CONTEXT

Noncontact anterior cruciate ligament injury has been reported to occur during the later stages of a game when fatigue is most likely present. Few researchers have focused on progressive changes in lower extremity biomechanics that occur throughout fatiguing.

OBJECTIVE

To evaluate the effects of a sequential fatigue protocol on lower extremity biomechanics during a sidestep-cutting task (SS).

DESIGN

Controlled laboratory study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Eighteen uninjured female collegiate soccer players (age = 19.2 ± 0.9 years, height = 1.66 ± 0.5 m, mass = 61.6 ± 5.1 kg) volunteered.

INTERVENTION(S)

The independent variable was fatigue level, with 3 levels (prefatigue, 50% fatigue, and 100% fatigue). Using 3-dimensional motion capture, we assessed lower extremity biomechanics during the SS. Participants alternated between a fatigue protocol that solicited different muscle groups and mimicked actual sport situations and unanticipated SS trials. The process was repeated until fatigue was attained.

MAIN OUTCOME MEASURE(S)

Dependent variables were hip- and knee-flexion and abduction angles and internal moments measured at initial contact and peak stance and defined as measures obtained between 0% and 50% of stance phase.

RESULTS

Knee-flexion angle decreased from prefatigue (-17° ± 5°) to 50% fatigue (-16° ± 6°) and to 100% fatigue (-14° ± 4°) (F2,34 = 5.112, P = .004). Knee flexion at peak stance increased from prefatigue (-52.9° ± 5.6°) to 50% fatigue (-56.1° ± 7.2°) but decreased from 50% to 100% fatigue (-50.5° ± 7.1°) (F2,34 = 8.282, P = 001). Knee-adduction moment at peak stance increased from prefatigue (0.49 ± 0.23 Nm/kgm) to 50% fatigue (0.55 ± 0.25 Nm/kgm) but decreased from 50% to 100% fatigue (0.37 ± 0.24) (F2,34 = 3.755, P = 03). Hip-flexion angle increased from prefatigue (45.4° ± 10.9°) to 50% fatigue (46.2° ± 11.2°) but decreased from 50% to 100% fatigue (40.9° ± 11.3°) (F2,34 = 6.542, P = .004). Hip flexion at peak stance increased from prefatigue (49.8° ± 9.9°) to 50% fatigue (52.9° ± 12.1°) but decreased from 50% to 100% fatigue (46.3° ± 12.9°) (F2,34 = 8.639, P = 001). Hip-abduction angle at initial contact decreased from prefatigue (-13.8° ± 6.6°) to 50% fatigue (-9.1° ± 6.5°) and to 100% fatigue (-7.8° ± 6.5°) (F2,34 = 11.228, P < .001). Hip-adduction moment decreased from prefatigue (0.14 ± 0.13 Nm/kgm) to 50% fatigue (0.08 ± 0.13 Nm/kgm) and to 100% fatigue (0.06 ± 0.05 Nm/kg) (F2,34 = 5.767, P = .007).

CONCLUSIONS

The detrimental effects of fatigue on sagittal and frontal mechanics of the hip and knee were visible at 50% of the participants' maximal fatigue and became more marked at 100% fatigue. Anterior cruciate ligament injury-prevention programs should emphasize feedback on proper mechanics throughout an entire practice and not only at the beginning of practice.

Injuries in Portuguese youth soccer players during training and match play

CONTEXT

Epidemiologic information on the incidence of youth soccer injuries in southern Europe is limited.

OBJECTIVE

To compare the incidence, type, location, and severity of injuries sustained by male subelite youth soccer players over the 2008-2009 season.

DESIGN

Descriptive epidemiology study.

SETTING

Twenty-eight Portuguese male youth soccer teams.

PATIENTS OR OTHER PARTICIPANTS

A total of 674 youth male subelite soccer players in 4 age groups: 179 U-13 (age range, 11-12 years), 169 U-15 (age range, 13-14 years), 165 U-17 (age range, 15-16 years), and 161 U-19 (age range, 17-18 years).

MAIN OUTCOME MEASURE(S)

Injuries that led to participation time missed from training and match play prospectively reported by medical or coaching staff of the clubs.

RESULTS

In total, 199 injuries reported in 191 players accounted for 14.6 ± 13.0 days of absence from practice. The incidence was 1.2 injuries per 1000 hours of exposure to soccer (95% confidence interval [CI] = 0.8, 1.6), with a 4.2-fold higher incidence during match play (4.7 injuries per 1000 hours of exposure; 95% CI = 3.0, 6.5) than during training (0.9 injuries per 1000 hours of exposure; 95% CI = 0.6, 1.3) (F₁,₆₇₃ = 17.592, P < .001). The overall incidence of injury did not increase with age (F₁,₆₇₃ = 1.299,P = .30), and the incidence of injury during matches (F₁,₆₇₃ = 2.037, P = .14) and training (F₁,₆₇₃ = 0.927, P = .44) did not differ among age groups. Collisions accounted for 57% (n = 113) of all injuries, but participation time missed due to traumatic injury did not differ among age groups (F₃,₁₁₀ = 1.044, P = .38). Most injuries (86%, n = 172) involved the lower extremity. The thigh was the most affected region (30%, n = 60) in all age groups. Muscle strains were the most common injuries among the U-19 (34%, n = 26), U-17 (30%, n = 17), and U-15 (34%, n = 14) age groups, whereas contusions and tendon injuries were the most common injuries in U-13 players (both 32%, n = 8). The relative risk of injury slightly increased with the age of the competitors.

CONCLUSIONS

The higher incidence of injury during matches than training highlights the need for education and prevention programs in youth soccer. These programs should focus on coach education aimed at improving skills, techniques, and fair play during competitions with the goal of reducing injuries.

Systematic review: Annual incidence of ACL injury and surgery in various populations

Accurate documentation of injury incidence is critical for study of injury risk factors and prevention. Comparisons of published incidences of anterior cruciate ligament (ACL) injuries and surgical reconstructions are difficult, however, because of the variations in units. Some studies report absolute time-based denominators (such as annual incidence or incidence per 100,000 person years), whereas others report exposure-based denominators (such as incidence per 1,000 player hours or athlete exposures). We converted exposure-based units into annual incidences to compare various studies. National population studies show annual incidence rates of up to 0.05% per person per year in Australia. Professional athletes in basketball, soccer, and the other football codes report an annual incidence of 0.15%-3.7% in studies with at least a moderate sample size. Annual ACL incidence in amateur sporting groups was generally higher than the entire population but lower than among professional athletes. Converting incidence rates to annual units allowed better comparisons to be made between population rates across different studies.

The effects of injury preventive warm-up programs on knee strength ratio in young male professional soccer players

PURPOSE

We aimed to investigate the effect of FIFA 11+ (11+) and HarmoKnee injury preventive warm-up programs on conventional strength ratio (CSR), dynamic control ratio (DCR) and fast/slow speed ratio (FSR) in young male professional soccer players. These ratios are related to the risk of injury to the knee in soccer players.

METHODS

Thirty-six players were divided into 3 groups; FIFA 11+, HarmoKnee and control (n = 12 per group). These exercises were performed 3 times per week for 2 months (24 sessions). The CSR, DCR and FSR were measured before and after the intervention.

RESULTS

After training, the CSR and DCR of knee muscles in both groups were found to be lower than the published normal values (0.61, 0.72, and 0.78 during 60°.s(-1), 180°.s(-1) and 300°.s(-1), respectively). The CSR (60°.s(-1)) increased by 8% and FSR in the quadriceps of the non-dominant leg by 8% in the 11+. Meanwhile, the DCR in the dominant and non-dominant legs were reduced by 40% and 30% respectively in the 11+. The CSR (60°.s(-1)) in the non-dominant leg showed significant differences between the 11+, HarmoKnee and control groups (p = 0.02). As for the DCR analysis between groups, there were significant differences in the non-dominant leg between both programs with the control group (p = 0.04). For FSR no significant changes were found between groups.

CONCLUSIONS

It can be concluded that the 11+ improved CSR and FSR, but the HarmoKnee program did not demonstrate improvement. We suggest adding more training elements to the HarmoKnee program that aimed to enhance hamstring strength (CSR, DCR and FSR). Professional soccer players have higher predisposition of getting knee injuries because hamstring to quadriceps ratio were found to be lower than the average values. It seems that the 11+ have potentials to improve CSR and FSR as well as prevent knee injuries in soccer players.

Return to play and future ACL injury risk after ACL reconstruction in soccer athletes from the Multicenter Orthopaedic Outcomes Network (MOON) group

BACKGROUND

There is limited information on outcomes and return to play (RTP) after anterior cruciate ligament reconstruction (ACLR) in soccer athletes.

PURPOSE

The purpose of this study was to (1) test the hypotheses that player sex, side of injury, and graft choice do not influence RTP and (2) define the risk for future ACL injury in soccer players after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Soccer players in a prospective cohort were contacted to determine RTP after ACLR. Information regarding if and when they returned to play, their current playing status, the primary reason they stopped playing soccer (if relevant), and incidence of subsequent ACL surgery was recorded.

RESULTS

Initially, 72% of 100 soccer athletes (55 male, 45 female) with a mean age of 24.2 years at the time of ACLR returned to soccer. At average follow-up of 7.0 years, 36% were still playing, a significant decrease compared with initial RTP (P < .0001). Based on multivariate analysis, older athletes (P = .006) and females (P = .037) were less likely to return to play. Twelve soccer athletes had undergone further ACL surgery, including 9 on the contralateral knee and 3 on the ipsilateral knee. In a univariate analysis, females were more likely to have future ACL surgery (20% vs 5.5%, P = .03). Soccer athletes who underwent ACLR on their nondominant limb had a higher future rate of contralateral ACLR (16%) than soccer athletes who underwent ACLR on their dominant limb (3.5%) (P = .03).

CONCLUSION

Younger and male soccer players are more likely to return to play after ACL reconstruction. Return to soccer after ACLR declines over time. ACLR on the nondominant limb potentially places the dominant limb at risk for future ACL injury.

Nine-year risk of depression diagnosis increases with increasing self-reported concussions in retired professional football players

BACKGROUND

Concussions may accelerate the progression to long-term mental health outcomes such as depression in athletes.

PURPOSE

To prospectively determine the effects of recurrent concussions on the clinical diagnosis of depression in a group of retired football players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Members of the National Football League Retired Players Association responded to a baseline General Health Survey (GHS) in 2001. They also completed a follow-up survey in 2010. Both surveys asked about demographic information, number of concussions sustained during their professional football career, physical/mental health, and prevalence of diagnosed medical conditions. A physical component summary (Short Form 36 Measurement Model for Functional Assessment of Health and Well-Being [SF-36 PCS]) was calculated from responses for physical health. The main exposure, the history of concussions during the professional playing career (self-report recalled in 2010), was stratified into 5 categories: 0 (referent), 1 to 2, 3 to 4, 5 to 9, and 10+ concussions. The main outcome was a clinical diagnosis of depression between the baseline and follow-up GHS. Classic tabular methods computed crude risk ratios. Binomial regression with a Poisson residual and robust variance estimation to stabilize the fitting algorithm estimated adjusted risk ratios. χ(2) analyses identified associations and trends between concussion history and the 9-year risk of a depression diagnosis.

RESULTS

Of the 1044 respondents with complete data from the baseline and follow-up GHS, 106 (10.2%) reported being clinically diagnosed as depressed between the baseline and follow-up GHS. Approximately 65% of all respondents self-reported sustaining at least 1 concussion during their professional careers. The 9-year risk of a depression diagnosis increased with an increasing number of self-reported concussions, ranging from 3.0% in the "no concussions" group to 26.8% in the "10+" group (linear trend: P < .001). A strong dose-response relationship was observed even after controlling for confounders (years retired from professional football and 2001 SF-36 PCS). Retired athletes with a depression diagnosis also had a lower SF-36 PCS before diagnosis. The association between concussions and depression was independent of the relationship between decreased physical health and depression.

CONCLUSION

Professional football players self-reporting concussions are at greater risk for having depressive episodes later in life compared with those retired players self-reporting no concussions.

Groin injuries in sports medicine

Context:

An in-season groin injury may be debilitating for the athlete. Proper diagnosis and identification of the pathology are paramount in providing appropriate intervention. Furthermore, an adductor strain that is treated improperly can become chronic and career threatening. Any one of the 6 muscles of the adductor muscle group can be involved. The degree of injury can range from a minor strain (grade 1), where minimal playing time is lost, to a severe strain (grade 3), in which there is complete loss of muscle function. Persistent groin pain and muscle imbalance may lead to athletic pubalgia.

Evidence Acquisition:

Relevant studies were identified through a literature search of MEDLINE and the Cochrane database from 1990 to 2009, as well as a manual review of reference lists of identified sources.

Results:

Ice hockey and soccer players seem particularly susceptible to adductor muscle strains. In professional ice hockey and soccer players throughout the world, approximately 10% to 11% of all injuries are groin strains. These injuries have been linked to hip muscle weakness, a previous injury to that area, preseason practice sessions, and level of experience. This injury may be prevented if these risk factors are addressed before each season.

Conclusion:

Despite the identification of risk factors and strengthening intervention for athletes, adductor strains continue to occur throughout sport. If groin pain persists, the possibility of athletic pubalgia needs to be explored, because of weakening or tears in the abdominal wall muscles. A diagnosis is confirmed by exclusion of other pathology.

The epidemiology, morbidity, and outcome of soccer-related fractures in a standard population

BACKGROUND

Soccer is the most common cause of sporting fracture, but little is known about patient outcome after such fractures.

PURPOSE

To describe the epidemiological characteristics of soccer-related fractures, their outcomes, and the likelihood of return to soccer after injury in a known United Kingdom population at all skill levels.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All soccer fractures during 2007-2008 in the Lothian population were prospectively collected, with the diagnosis confirmed by an orthopaedic surgeon when patients attended the only adult orthopaedic service in Lothian. Patients living outside the region were excluded from the study. Patients were contacted in August 2010 to ascertain their progress in returning to soccer.

RESULTS

A total of 367 fractures were recorded over the study period in 357 patients; 312 fractures (85%) in 303 patients (85%) were followed up, with a mean interval of 30 months (range, 24-36 months). The mean time for return to soccer from injury was 15 ± 17 weeks (range, 0-104 weeks). For patients with lower limb injuries, the mean time was 26 ± 22 weeks (range, 4-104 weeks) compared with 9 ± 8 weeks for patients with upper limb injuries (range, 0-64 weeks). Fourteen percent of the whole cohort did not return to soccer; 83% returned to soccer at the same level or higher. Thirty-nine percent had ongoing related problems; however, only 8% had impaired soccer ability because of these problems. Fractures with the highest morbidity in not returning to soccer were to the clavicle (24%), distal radius (21%), and tibial diaphysis (20%).

CONCLUSION

Most patients sustaining a fracture while playing soccer will return to soccer at a similar level. While over one third of them will have persisting symptoms 2 years after injury, for the majority, this will not impair their soccer ability.

Q-angle, Pelvic width, and Intercondylar notch width as predictors of knee injuries in women soccer players in South Africa

OBJECTIVE

To investigate the association between the three anatomical factors of Q-angle (QA), pelvic width (PW) and Intercondylar notch width (INW) and knee injuries among the U-23 female soccer players of South Africa

METHODS

The study is a case-control prospective study design. Twenty four U-23 women soccer players of the South African team were purposively chosen to participate in this study. Participants were divided into two groups: group 1 (Case) was those with knee injuries, while those without injuries were in group-2 (Control). PW and INW were measured after X-rays of the hip were taken while the QA was measured manually with the goniomenter. Association between anatomical factors and knee injuries were tested with ANOVA.

RESULTS

Q-angle ranged from 14° to 18° for both injured and non injured groups. PW was between 24 -29 cm for both injured and non injured groups. INW was between 1.3mm and 2.8mm for the right and between 1.4mm and 2.5mm for the left notch for the injured group, while INW for the right and left of the non injured group were between 1.7 mm to 2.1 mm and 1.8 mm to 2.1 mm, respectively No significant association between knee injuries and each of the anatomical factors was found QA (p= 0.74), PW (p=0.34), INW (right and left respectively) (p=0.142 & p=0.089).

CONCLUSION

The three anatomical factors of QA, PW and INW could not be used to predict knee injuries amongst the U-23 female players in South Africa.

Clinical and Basic Science of Cartilage Injury and Arthritis in the Football (Soccer) Athlete

Joint injuries are very common in the athletic population, especially professional soccer players, with an incidence of 10 to 35.5 injuries per 1000 hours. Most soccer-related joint injuries occur in the lower extremities, with 16% to 46% occurring in the knee and 17% to 40% occurring in the ankle. Because of the limited healing capacity of cartilage and other intra-articular soft tissue structures, such as anterior cruciate ligament (ACL) and meniscus, joint injuries often lead to the development of early disabling osteoarthritis. Osteoarthritis in soccer players is 5 to 12 times more frequent than in the general population and diagnosed 4 to 5 years earlier. It remains a major cause of disability from this sport. This review focuses on the epidemiology of soccer-related joint injuries and subsequent development of osteoarthritis in the hip, knee, and ankle joints. As well, two different pathways for pathogenesis are described: (1) primary osteoarthritis via direct trauma to the articular cartilage and (2) secondary osteoarthritis that occurs indirectly through injury to the soft tissue structures that subsequently result in articular cartilage degeneration and loss.

Anterior cruciate ligament injury in elite football: a prospective three-cohort study

Anterior cruciate ligament (ACL) injury causes long lay-off time and is often complicated with subsequent new knee injury and osteoarthritis. Female gender is associated with an increased ACL injury risk, but few studies have adjusted for gender-related differences in age although female players are often younger when sustaining their ACL injury. The objective of this three-cohort study was to describe ACL injury characteristics in teams from the Swedish men's and women's first leagues and from several European men's professional first leagues. Over a varying number of seasons from 2001 to 2009, 57 clubs (2,329 players) were followed prospectively and during this period 78 ACL injuries occurred (five partial). Mean age at ACL injury was lower in women compared to men (20.6 ± 2.2 vs. 25.2 ± 4.5 years, P = 0.0002). Using a Cox regression, the female-to-male hazard ratio (HR) was 2.6 (95% CI 1.4-4.6) in all three cohorts studied and 2.6 (95% CI 1.3-5.3) in the Swedish cohorts; adjusted for age, the HR was reduced to 2.4 (95% CI 1.3-4.2) and 2.1 (95% CI 1.0-4.2), respectively. Match play was associated with a higher ACL injury risk with a match-to-training ratio of 20.8 (95% CI 12.4-34.8) and 45 ACL injuries (58%) occurred due to non-contact mechanisms. Hamstrings grafts were used more often in Sweden than in Europe (67 vs. 34%, P = 0.028), and there were no differences in time to return to play after ACL reconstruction between the cohorts or different grafts. In conclusion, this study showed that the ACL injury incidence in female elite footballers was more than doubled compared to their male counterparts, but also that they were significantly younger at ACL injury than males. These findings suggest that future preventive research primarily should address the young female football player.

The epidemiology of anterior cruciate ligament injury in football (soccer): a review of the literature from a gender-related perspective

Football (soccer), the most popular sport worldwide, is associated with a high injury risk, and the knee joint is often affected. Several studies have found female players to be more susceptible to knee injury, anterior cruciate ligament (ACL) injury in particular, compared to their male counterparts. There is, however, some controversy regarding the magnitude of this risk increase and a few studies have found no differences. The influence of age and activity type on gender-related differences in injury risk is only scarcely investigated. In this paper, the literature reporting gender-specific ACL injury risk in football is reviewed. A literature search yielded 33 relevant articles that were included for review. These show that female players have a 2-3 times higher ACL injury risk compared to their male counterparts. Females also tend to sustain their ACL injury at a younger age than males, and a limiting factor in the existing literature is that age is not adjusted for in comparisons of ACL injury risk between genders. Furthermore, the risk increase in females is primarily evident during match play, but type of exposure is also rarely adjusted for. Finally, the studies included in this review share important methodological limitations that are discussed as a starting point for future research in the field.

Injury in community-level soccer: development of an injury surveillance system

BACKGROUND

Few descriptive epidemiologic studies of injury in soccer are of community-level players. Although many sports injury surveillance systems have been described in the scientific literature, only 1 has been implemented in community-level soccer and that was restricted to adolescent players in a single club.

PURPOSE

The objective of this study was to develop a method for undertaking routine surveillance of injury in community-level soccer.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A cohort of 880 community-level players aged 13 years and over was followed over 1 winter competitive season. Each week, each player was contacted by telephone and an interview conducted to collect data on participation in matches and training sessions, injuries, and adherence to injury prevention measures.

RESULTS

Seventy-five percent (n = 510) of the cohort was male and the median age was 16 years. Data were collected on 11 268 player-matches totaling 13 483 player-match hours and 11 540 player-training sessions totaling 16 031 player-training hours. A total of 677 match injury events were reported, giving overall incidence rates of 50.2 injury events per 1000 player-match hours and 6.0 injury events per 100 player-matches. The incidence rate for match injury events was significantly higher for females than for males (63.9 vs 46.9). A total of 145 training injury events were reported, giving overall incidence rates of 9.0 injury events per 1000 player-training hours and 1.3 injury events per 100 player-training sessions. The most common injuries were sprains and strains of the lower limb, and tackling was the most common cause of injury.

CONCLUSION

This study has shown that routine injury surveillance, using a cohort design with exposure measurement, can be successfully implemented in community-level soccer.

Differences between sexes in lower extremity alignment and muscle activation during soccer kick

BACKGROUND

Injury risk in soccer varies by sex. Female soccer players face a greater risk of anterior cruciate ligament injury and patellofemoral problems, while male players are more likely to experience sports hernia symptoms. The purpose of this study was to test the hypothesis that females have different lower-extremity alignment and muscle activation patterns than males during the soccer kick.

METHODS

Thirteen male and twelve female college soccer players underwent three-dimensional motion analysis and electromyography of seven muscles (iliacus, gluteus maximus, gluteus medius, vastus lateralis, vastus medialis, hamstrings, and gastrocnemius) in both the kicking and the supporting lower extremity and two additional muscles (hip adductors and tibialis anterior) in the kicking limb only. Five instep and five side-foot kicks were recorded for each player. Muscle activation was recorded as a percentage of maximum voluntary isometric contraction.

RESULTS

The male soccer players had significantly higher mean muscle activation than their female counterparts with respect to the iliacus in the kicking limb (123% compared with 34% of maximal voluntary isometric contraction; p = 0.0007) and the gluteus medius (124% compared with 55%; p = 0.005) and vastus medialis muscles (139% compared with 69%; p = 0.002) in the supporting limb. The supporting limb reached significantly greater mean hip adduction during the stance phase of the kick in the females compared with that in the males (15 degrees and 10 degrees, respectively; p = 0.006).

CONCLUSIONS

Differences between the sexes in lower extremity alignment and muscle activation occur during the soccer instep and side-foot kicks. Decreased activation of the hip abductors and greater hip adduction in the supporting limb during the soccer kick in female athletes may be associated with their increased risk for anterior cruciate ligament injury.