Injuries among male and female elite football players

A previous hamstring injury affects kicking mechanics in soccer players

BACKGROUND

Although the kicking skill is influenced by limb dominance and sex, how a previous hamstring injury affects kicking has not been studied in detail. Thus, the objective of this study was to evaluate the effect of sex and limb dominance on kicking in limbs with and without a previous hamstring injury.

METHODS

Forty-five professional players (males: N.=19, previously injured players=4, age=21.16±2.00 years; females: N.=19, previously injured players =10, age= 22.15±4.50 years) performed 5 kicks each with their preferred and non-preferred limb at a target 7m away, which were recorded with a three-dimensional motion capture system. Kinematic and kinetic variables were extracted for the backswing, leg cocking, leg acceleration and follow through phases.

RESULTS

A shorter backswing (20.20±3.49% vs. 25.64±4.57%), and differences in knee flexion angle (58±10º vs. 72±14º) and hip flexion velocity (8±0 rad/s vs. 10±2 rad/s) were observed in previously injured, non-preferred limb kicks for females. A lower peak hip linear velocity (3.50±0.84 m/s vs. 4.10±0.45 m/s) was observed in previously injured, preferred limb kicks of females. These differences occurred in the backswing and leg-cocking phases where the hamstring muscles were the most active. A variation in the functioning of the hamstring muscles and that of the gluteus maximus and iliopsoas in the case of a previous injury could account for the differences observed in the kicking pattern.

CONCLUSIONS

Therefore, the effects of a previous hamstring injury must be considered while designing rehabilitation programs to re-educate kicking movement.

Epidemiology of Hip Flexor and Hip Adductor Strains in National Collegiate Athletic Association Athletes, 2009/2010-2014/2015

BACKGROUND

Little research has examined the rates and patterns of hip flexor or hip adductor strains in student-athletes in the National Collegiate Athletic Association (NCAA).

PURPOSE

To describe the epidemiology of hip flexor and adductor strains in NCAA athletes during the 2009/2010-2014/2015 academic years.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

Rates and patterns of hip flexor and adductor strains in collegiate sports were examined in a convenience sample of NCAA varsity teams from 25 sports. Rates and distributions of strains by mechanism, recurrence, and participation restriction time were examined. Injury rate ratios (IRRs) and proportion ratios were calculated to compare rates within and between sports by event type, sex, mechanism, recurrence, and participation restriction time.

RESULTS

A total of 770 hip flexor and 621 hip adductor strains were reported, resulting in overall injury rates of 1.60 and 1.29 per 10,000 athlete-exposures (AEs), respectively. In men, the rate of hip flexor strains was 1.81 per 10,000 AEs, and that for hip adductor strains was 1.71 per 10,000 AEs. In women, the rate of hip flexor strains was 1.59 per 10,000 AEs, and the rate of hip adductor strains was 1.15 per 10,000 AEs. The highest rates of strains were found in men's soccer and men's ice hockey (range, 2.47-3.77 per 10,000 AEs). Most hip flexor and hip adductor strains occurred in practice, but both had higher rates in competition. In sex-comparable sports, hip flexor strain rates did not differ between the sexes (IRR = 1.14; 95% CI, 0.96-1.36), but the rate of hip adductor strains was higher in men than women (IRR = 1.49; 95% CI, 1.22-1.81). Noncontact was the most common mechanism for both types of strains (hip flexor strains, 59.4%; hip adductor strains, 62.5%); 10.1% of hip flexor strains and 11.1% of hip adductor strains were recurrent. The highest rates of recurrence of both types of strain were found in men's and women's ice hockey (range, 16.0%-30.6%). Most hip flexor and hip adductor strains resulted in <1 week of participation restriction (hip flexor strains, 83.8%; hip adductor strains, 82.9%).

CONCLUSION

The NCAA sports with the highest rates of hip flexor and hip adductor strains were men's soccer and men's ice hockey. In sex-comparable sports, men had a higher rate of hip adductor, but not hip flexor, strains. Recurrence rates were remarkably high in ice hockey. Male sports teams, especially soccer and ice hockey, should place an emphasis on prevention programs for hip adductor strains. Secondary prevention programs involving thorough rehabilitation and strict return-to-play criteria should be developed and implemented to curb the high recurrence rate of these injuries, particularly in ice hockey.

Prognostic factors for specific lower extremity and spinal musculoskeletal injuries identified through medical screening and training load monitoring in professional football (soccer): a systematic review

Background

Medical screening and load monitoring procedures are commonly used in professional football to assess factors perceived to be associated with injury.

Objectives

To identify prognostic factors (PFs) and models for lower extremity and spinal musculoskeletal injuries in professional/elite football players from medical screening and training load monitoring processes.

Methods

The MEDLINE, AMED, EMBASE, CINAHL Plus, SPORTDiscus and PubMed electronic bibliographic databases were searched (from inception to January 2017). Prospective and retrospective cohort studies of lower extremity and spinal musculoskeletal injury incidence in professional/elite football players aged between 16 and 40 years were included. The Quality in Prognostic Studies appraisal tool and the modified Grading of Recommendations Assessment, Development and Evaluation synthesis approach was used to assess the quality of the evidence.

Results

Fourteen studies were included. 16 specific lower extremity injury outcomes were identified. No spinal injury outcomes were identified. Meta-analysis was not possible due to heterogeneity and study quality. All evidence related to PFs and specific lower extremity injury outcomes was of very low to low quality. On the few occasions where multiple studies could be used to compare PFs and outcomes, only two factors demonstrated consensus. A history of previous hamstring injuries (HSI) and increasing age may be prognostic for future HSI in male players.

Conclusions

The assumed ability of medical screening tests to predict specific musculoskeletal injuries is not supported by the current evidence. Screening procedures should currently be considered as benchmarks of function or performance only. The prognostic value of load monitoring modalities is unknown.

Incidence and body location of reported acute sport injuries in seven sports using a national insurance database

Sports with high numbers of athletes and acute injuries are an important target for preventive actions at a national level. Both for the health of the athlete and to reduce costs associated with injury. The aim of this study was to identify injuries where injury prevention should focus, in order to have major impact on decreasing acute injury rates at a national level. All athletes in the seven investigated sport federations (automobile sports, basketball, floorball, football (soccer), handball, ice hockey, and motor sports) were insured by the same insurance company. Using this insurance database, the incidence and proportion of acute injuries, and injuries leading to permanent medical impairment (PMI), at each body location, was calculated. Comparisons were made between sports, sex, and age. In total, there were 84 754 registered injuries during the study period (year 2006-2013). Athletes in team sports, except in male ice hockey, had the highest risk to sustain an injury and PMI in the lower limb. Females had higher risk of injury and PMI in the lower limb compared to males, in all sports except in ice hockey. This study recommends that injury prevention at national level should particularly focus on lower limb injuries. In ice hockey and motor sports, head/neck and upper limb injuries also need attention.

Perceptions of football players regarding injury risk factors and prevention strategies

Current approaches regarding injury prevention focus on the transfer of evidence into daily practice. One promising approach is to influence attitudes and beliefs of players. The objective of this study was to record player’s perceptions on injury prevention. A survey was performed among players of one German high-level football (soccer) club. 139 professional and youth players between age 13 and 35 years completed a standardized questionnaire (response rate = 98%). It included categories with (1) history of lower extremity injuries, (2) perceptions regarding risk factors and (3) regularly used prevention strategies.

The majority of players (84.2%) had a previous injury. 47.5% of respondents believe that contact with other players is a risk factor, followed by fatigue (38.1%) and environmental factors (25.9%). The relevance of previous injuries as a risk factor is differently perceived between injured (25%) and uninjured players (0.0%). Nearly all players (91.5%) perform stretching to prevent injuries, followed by neuromuscular warm up exercises (54.0%). Taping is used by 40.2% of previously injured players and 13.6% of players without a history of injuries. In conclusion, the perception of risk factors and performed preventive strategies are inconsistent with scientific evidence. Future transfer strategies should incorporate the players beliefs and attitudes.

Groin Problems in Male Soccer Players Are More Common Than Previously Reported

BACKGROUND

The majority of surveillance studies in soccer have used a time-loss injury definition, and many groin problems result from overuse, leading to gradually increasing pain and/or reduced performance without necessarily causing an absence from soccer training or match play. Thus, the magnitude of groin problems in soccer has probably been underestimated in previous studies based on traditional injury surveillance methods.

PURPOSE

To investigate the prevalence of groin problems among soccer players of both sexes and among male soccer players at different levels of play through a new surveillance method developed to capture acute and overuse problems.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

We registered groin problems during a 6-week period of match congestion using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A total of 240 players from 15 teams across different levels of play and from both sexes were included, and they responded to the weekly questionnaire. We calculated the average weekly prevalence of all groin problems and substantial groin problems.

RESULTS

Of the 240 players, 112 male players (59%) and 20 female players (45%) reported at least 1 episode of groin problems. The average weekly prevalence of any groin problem and substantial groin problem for all male players was 29% (range, 23%-32% across different levels) and 10% (7%-13%), respectively. Elite male players had an increased risk of experiencing groin problems (odds ratio: 3.1, 95% CI: 1.5-6.4, P = .03) compared with elite female players. There was no difference in the risk of experiencing groin problems among elite, subelite, and amateur male players. For substantial problems, there was no difference between elite male and elite female players or among levels of play for senior male soccer players.

CONCLUSION

We found a high prevalence of groin problems among male soccer players during a period with match congestion. Time-loss definition as used in previous injury surveillance studies captured only one-third of the male groin problems registered with the new method. Elite male players had 3 times' higher risk of reporting groin problems as compared with elite female players, while playing level did not influence the risk of reporting a groin problem among males.

Return to Play After Hamstring Injuries: A Qualitative Systematic Review of Definitions and Criteria

Background

More than half of the recurrent hamstring injuries occur within the first month after return-to-play (RTP). Although there are numerous studies on RTP, comparisons are hampered by the numerous definitions of RTP used. Moreover, there is no consensus on the criteria used to determine when a person can start playing again. These criteria need to be critically evaluated, in an attempt to reduce recurrence rates and optimize RTP.

Objective

To carry out a systematic review of the literature on (1) definitions of RTP used in hamstring research and (2) criteria for RTP after hamstring injuries.

Study Design

Systematic review.

Methods

Seven databases (PubMed, EMBASE/MEDLINE, CINAHL, PEDro, Cochrane, SPORTDiscus, Scopus) were searched for articles that provided a definition of, or criteria for, RTP after hamstring injury. There were no limitations on the methodological design or quality of articles. Content analysis was used to record and analyze definitions and criteria for RTP after hamstring injury.

Results

Twenty-five papers fulfilled inclusion criteria, of which 13 provided a definition of RTP and 23 described criteria to support the RTP decision. “Reaching the athlete’s pre-injury level” and “being able to perform full sport activities” were the primary content categories used to define RTP. “Absence of pain”, “similar strength”, “similar flexibility”, “medical staff clearance”, and “functional performance” were core themes to describe criteria to support the RTP decision after hamstring injury.

Conclusion

Only half of the included studies provided some definition of RTP after hamstring injury, of which reaching the athlete’s pre-injury level and being able to perform full sport activities were the most important. A wide variety of criteria are used to support the RTP decision, none of which have been validated. More research is needed to reach a consensus on the definition of RTP and to provide validated RTP criteria to facilitate hamstring injury management and reduce hamstring injury recurrence.

PROSPERO systematic review registration number: CRD42015016510.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-015-0468-7) contains supplementary material, which is available to authorized users.

Return to play after hamstring injuries in football (soccer): a worldwide Delphi procedure regarding definition, medical criteria and decision-making

There are three major questions about return to play (RTP) after hamstring injuries: How should RTP be defined? Which medical criteria should support the RTP decision? And who should make the RTP decision? The study aimed to provide a clear RTP definition and medical criteria for RTP and to clarify RTP consultation and responsibilities after hamstring injury. The study used the Delphi procedure. The results of a systematic review were used as a starting point for the Delphi procedure. Fifty-eight experts in the field of hamstring injury management selected by 28 FIFA Medical Centres of Excellence worldwide participated. Each Delphi round consisted of a questionnaire, an analysis and an anonymised feedback report. After four Delphi rounds, with more than 83% response for each round, consensus was achieved that RTP should be defined as ‘the moment a player has received criteria-based medical clearance and is mentally ready for full availability for match selection and/or full training’. The experts reached consensus on the following criteria to support the RTP decision: medical staff clearance, absence of pain on palpation, absence of pain during strength and flexibility testing, absence of pain during/after functional testing, similar hamstring flexibility, performance on field testing, and psychological readiness. It was also agreed that RTP decisions should be based on shared decision-making, primarily via consultation with the athlete, sports physician, physiotherapist, fitness trainer and team coach. The consensus regarding aspects of RTP should provide clarity and facilitate the assessment of when RTP is appropriate after hamstring injury, so as to avoid or reduce the risk of injury recurrence because of a premature RTP.

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.

Negative psychological responses of injury and rehabilitation adherence effects on return to play in competitive athletes: a systematic review and meta-analysis

Previous research offers evidence that psychological factors influence an injured athlete during the rehabilitation process. Our first objective was to conduct a systematic review and meta-analysis of the results from all published studies that examined the relationships among negative affective responses after sport injuries, rehabilitation adherence, and return to play (RTP). The second objective was to use a meta-analytic path analysis to investigate whether an indirect effect existed between negative affective responses and RTP through rehabilitation adherence. This literature review resulted in seven studies providing 14 effect sizes. The results from the meta-analysis showed that negative affective responses had a negative effect on successful RTP, whereas rehabilitation adherence had a positive effect on RTP. The results from the meta-analytic path analysis showed a weak and nonsignificant indirect effect of negative affective responses on RTP via rehabilitation adherence. These results underline the importance of providing supportive environments for injured athletes to increase the chances of successful RTP via a decrease in negative affective responses and increase in rehabilitation adherence.

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.

No Effect of Generalized Joint Hypermobility on Injury Risk in Elite Female Soccer Players: A Prospective Cohort Study

BACKGROUND

Although it has been suggested that generalized joint hypermobility (GJH) is a risk factor for injury in soccer players, it remains unclear whether this applies to elite female soccer players.

PURPOSE

To investigate whether GJH is a risk factor for injury in elite female soccer players.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Elite female soccer players in the Netherlands were screened at the start of the 2014-2015 competitive season. GJH was assessed using the Beighton score. Soccer injuries and soccer exposure were registered throughout the entire season. Poisson regression was performed to calculate incidence risk ratios (IRRs) using different cutoff points of the Beighton score (≥3, ≥4, and ≥5) to indicate GJH.

RESULTS

Of the 114 players included in the study, 20 were classified as hypermobile (Beighton score ≥4). The mean (±SD) injury incidence per player was 8.40 ± 9.17 injuries/1000 hours of soccer, with no significant difference between hypermobile and nonhypermobile players. GJH was not a risk factor for injuries when using Beighton score cutoff points of ≥3 (IRR = 1.06 [95% CI, 0.74-1.50]; P = .762), ≥4 (IRR = 1.10 [95% CI, 0.72-1.68]; P = .662), or ≥5 (IRR = 1.15 [95% CI, 0.68-1.95]; P = .602). Similarly, GJH was not a significant risk factor for thigh, knee, or ankle injuries evaluated separately.

CONCLUSION

This study indicates that GJH is not a risk factor for injuries in elite female soccer players, irrespective of Beighton score cutoff point. Hypermobile players at this elite level might have improved their active stability and/or used braces to compensate for joint laxity.

Effects of a 10-Week Nordic Hamstring Exercise and Russian Belt Training on Posterior Lower-Limb Muscle Strength in Elite Junior Soccer Players

Rey, E, Paz-Domínguez, Á, Porcel-Almendral, D, Paredes-Hernández, V, Barcala-Furelos, R, and Abelairas-Gómez, C. Effects of a 10-week Nordic hamstring exercise and Russian belt training on posterior lower-limb muscle strength in elite junior soccer players. J Strength Cond Res 31(5): 1198-1205, 2017-The purpose of this study was to assess the effect of 2 eccentric hamstring training exercises, Nordic hamstring exercise (NHE) and Russian belt (RB), on lower-limb strength and bilateral asymmetry using the single-leg hamstring bridge (SLHB) test. Forty-seven elite junior soccer players (age 17.7 ± 0.5 years, height 175.3 ± 3.6 cm, body mass 68.1 ± 7.4 kg) were randomized into 1 of 3 groups, the NHE group (n = 16), RB group (n = 15), or the control group (CG) (n = 16). The eccentric training intervention consisted of 27 supervised training sessions over 10 weeks. Within-group analysis showed significant improvements (p < 0.001) in right SLHB (+25.52% for NHE and +18.33% for RB) and left SLHB (+28.92% for NHE and +20.08% for RB) from pretest to posttest in NHE and RB. However, no significant pre-post changes were observed for the CG in any variable. In addition, a significant time effect (p = 0.028) was also observed for NHE in bilateral asymmetry decreasing from pre- to posttest. In the between-groups analysis, significant better results were found in right SLHB and left SLHB, in the NHE group and RB group in comparison with CG. However, there were no differences between the eccentric training groups (NHE vs. RB). The RB seems to be a viable alternative to the NHE to developing posterior lower-limb muscle strength based on SLHB.

Rehabilitation after first-time anterior cruciate ligament injury and reconstruction in female football players: a study of resilience factors

Background

Most of the research in the area of psychosocial factors in rehabilitation after sports injuries has focused on risk behaviors, while relatively few studies have focused on behaviors that facilitate rehabilitation. The objective of our study was to understand the psychosocial features that characterize elite female football players who express a resilient behaviour during rehabilitation after a first-time anterior cruciate ligament (ACL) injury and reconstruction.

Methods

A qualitative method was used based on individual in-person interviews and video communication of players who incurred a first-time ACL tear during the 2012 season of the Swedish Women’s Elite Football League. In total, 13 players had a first-time ACL and were interviewed post-season. The interviews were followed by a thematic content analysis. Based on this, eight players were identified as showing resilient behaviors during their rehabilitation and were included in the final analysis.

Results

Three core themes representing psychosocial factors that help players cope successfully with rehabilitation were identified: (I) constructive communication and rich interaction with significant others; (II) strong belief in the importance and efficacy of one’s own actions; and (III) the ability to set reasonable goals.

Conclusions

The findings suggest three core themes of psychosocial factors that characterize first-time ACL-injured elite female football players showing resilience during rehabilitation after ACL reconstruction. Suggestions for medical teams about ways to support communication, self-efficacy, and goal-setting during the rehabilitation process, are provided.

Injuries in Swedish floorball: a cost analysis

The epidemiology of sport injuries is well documented. However, the costs are rarely discussed. Previous studies have presented such costs in specific sports or localization. No study has investigated the costs related to injuries in elite floorball. Thus, the aim of this study was to estimate cost of injuries in Swedish elite floorball players. During 1 year, 346 floorball players were prospectively followed. All time-loss injures were recorded. The injured players were asked to complete a questionnaire regarding their costs tied to the injury. Mean costs were calculated by multiplying the total resource use with the collected unit costs and dividing these total costs with the number of injuries as well as players. The results showed that the average cost per injury increased with the level of severity and ranged from 332 to 2358 Euros. The mild and moderate overuse injuries were costlier than the corresponding traumatic injuries. However, the severe traumatic injuries were associated with higher costs than overuse injuries. Knee injuries were the costliest. Our results indicate that there are costs to be saved, if floorball injuries can be avoided. They should be of interest to decision makers deciding whether to invest in preventive interventions.

Fracture epidemiology in male elite football players from 2001 to 2013: 'How long will this fracture keep me out?'

BACKGROUND

Determining fracture risk and rehabilitation periods after specific fractures in professional football is essential for team planning.

AIM

To identify fracture epidemiology and absences after different types of fractures in male professional football players.

METHODS

2439 players from 41 professional male teams in 10 countries were followed prospectively from 2001 to 2013. Team medical staff registered fractures, absences after fractures and player exposure.

RESULTS

364 fractures were recorded, with an incidence of 0.27/1000 h of exposure (95% CI 0.25 to 0.30). The incidence of traumatic fractures was 0.25 (0.22 to 0.27) and that of stress fractures was 0.03 (0.02 to 0.04). 45% of traumatic fractures and 86% of stress fractures affected the lower extremities. Absence after a fracture was 32 days (1-278) (median (range)), compared to that after a traumatic fracture of 30 days (1-278) and a stress fracture of 65 days (6-168) (p<0.001). Annual fracture incidence was stable during the study period (R(2)=0.051, b=-0.011 (95% CI -0.043 to 0.021)). Young players had a relative risk of 10.9 (3.3 to 35.6) of sustaining stress fractures compared to old players (p<0.01). The fracture incidence did not differ between individuals in different playing positions (p=0.10).

SUMMARY

A male professional football team can expect 1 to 2 fractures per season. There are more traumatic fractures than stress fractures; while most fractures affect the lower extremities, stress fractures yield longer absences than traumatic fractures and young players have more stress fractures than old players. There is no difference in risk among players at different playing positions.

Epidemiology of injuries in female high school soccer players

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Short biceps femoris fascicles and eccentric knee flexor weakness increase the risk of hamstring injury in elite football (soccer): a prospective cohort study

BACKGROUND/AIM

To investigate the role of eccentric knee flexor strength, between-limb imbalance and biceps femoris long head (BFlh) fascicle length on the risk of future hamstring strain injury (HSI).

METHODS

Elite soccer players (n=152) from eight different teams participated. Eccentric knee flexor strength during the Nordic hamstring exercise and BFlh fascicle length were assessed at the beginning of preseason. The occurrences of HSIs following this were recorded by the team medical staff. Relative risk (RR) was determined for univariate data, and logistic regression was employed for multivariate data.

RESULTS

Twenty seven new HSIs were reported. Eccentric knee flexor strength below 337 N (RR=4.4; 95% CI 1.1 to 17.5) and possessing BFlh fascicles shorter than 10.56 cm (RR=4.1; 95% CI 1.9 to 8.7) significantly increased the risk of a HSI. Multivariate logistic regression revealed significant effects when combinations of age, history of HSI, eccentric knee flexor strength and BFlh fascicle length were explored. From these analyses the likelihood of a future HSI in older athletes or those with a HSI history was reduced if high levels of eccentric knee flexor strength and longer BFlh fascicles were present.

CONCLUSIONS

The presence of short BFlh fascicles and low levels of eccentric knee flexor strength in elite soccer players increases the risk of future HSI. The greater risk of a future HSI in older players or those with a previous HSI is reduced when they have longer BFlh fascicles and high levels of eccentric strength.

The efficacy of exercise in preventing injury in adult male football: a systematic review of randomised controlled trials

BACKGROUND

Injury prevention measures might reduce the impact of injury on footballers and football clubs. Increasing research has evaluated the use of exercise for injury prevention. However, research has focused on adolescent females. No high-quality systematic reviews have evaluated the efficacy of all forms of exercise on preventing injury in adult male football.

OBJECTIVE

Our objective was to conduct a systematic review to evaluate the efficacy of exercise in preventing injury in adult male football.

DATA SOURCES

Comprehensive searches of electronic databases CINAHL (Cumulative Index to Nursing and Allied Health Literature), MEDLINE, Embase, AMED (The Allied and Complementary Medicine Database), the Cochrane Central Register of Controlled Trials, PEDro (The Physiotherapy Evidence Database), SPORTDiscus™, the National Research Register, Current Controlled Trials website (York), and http://www.ClinicalTrials.gov were conducted using predefined search terms to identify relevant studies published up to 1 March 2013. Screening of references, searches of grey literature, and hand searches of relevant journals were also employed.

STUDY SELECTION

Included studies were randomized controlled trials using injury incidence as an outcome measure to evaluate the efficacy of an exercise intervention on uninjured male footballers aged 16 years and over. Articles not written in English were excluded.

DATA EXTRACTION

Two researchers independently searched data sources, screened studies for eligibility, evaluated risk of bias, and extracted data using predefined criteria.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias of included trials was assessed using the Cochrane Collaboration's tool for assessing risk of bias. There was insufficient trial comparability (outcome measures, interventions, injury type) for meta-analysis, and a qualitative analysis was performed.

RESULTS

Eight trials (n = 3,355) from five countries met the inclusion criteria. All trials were assessed as having a high risk of bias. Two trials reported statistically significant reductions in hamstring injuries with eccentric exercise, and two reported statistically significant reductions in recurrent ankle sprains with proprioceptive exercise. Four trials showed no statistically significant difference in injury incidence with exercise interventions targeting a range of injuries.

LIMITATIONS

Notable limitations of included trials included poor reporting and limited blinding. A high risk of bias and insufficient comparability across trials prevented quantitative data synthesis.

CONCLUSIONS

Limitations in the context of study quality and heterogeneity resulted in an inability to reach a clear conclusion regarding efficacy of exercise for injury prevention in adult male football. Future low risk of bias, properly powered, and comprehensively reported trials are warranted to evaluate the efficacy of exercise on injury prevention. The use of eccentric hamstring exercise for hamstring injury prevention and proprioceptive training for recurrent ankle sprain prevention might be a good focus for future trials, as existing trials with a high risk of bias suggest an effect.

Diagnosis of Acute Groin Injuries: A Prospective Study of 110 Athletes

BACKGROUND

Acute groin injuries are common in high-intensity sports, but there are insufficient data on injury characteristics such as injury mechanisms and clinical and radiological findings.

PURPOSE

To describe these characteristics in a cohort of athletes.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 110 male athletes (mean age, 25.6 ± 4.7 years) with sports-related acute groin pain were prospectively included within 7 days of injury from August 2012 to April 2014. Standardized history taking, a clinical examination, magnetic resonance imaging (MRI), and/or ultrasound (US) were performed.

RESULTS

The most frequent injury mechanism in soccer was kicking (40%), and change of direction was most frequent in other sports (31%). Clinically, adductor injuries accounted for 66% of all injuries and primarily involved the adductor longus on imaging (91% US, 93% MRI). The iliopsoas and proximal rectus femoris were also frequently injured according to all examination modalities (15%-25%). Acute injury findings were negative in 22% of the MRI and 25% of the US examinations. Of the clinically diagnosed adductor injuries, 3% (US) and 6% (MRI) showed a radiological injury in a different location compared with 35% to 46% for clinically diagnosed iliopsoas and proximal rectus femoris injuries.

CONCLUSION

Adductor injuries account for the majority of acute groin injuries. Iliopsoas and proximal rectus femoris injuries are also common. More than 1 in 5 injuries showed no imaging signs of an acute injury. Clinically diagnosed adductor injuries were often confirmed on imaging, whereas iliopsoas and rectus femoris injuries showed a different radiological injury location in more than one-third of the cases. The discrepancy between clinical and radiological findings should be considered when diagnosing acute groin injuries.

Injury characteristics in the German professional male soccer leagues after a shortened winter break

CONTEXT

The winter break in the top 2 German professional soccer leagues was shortened from 6.5 to 3.5 weeks in the 2009-2010 season.

OBJECTIVE

To investigate whether this change affected injury characteristics by comparing the second half of the 2008-2009 (long winter break) with the equivalent period in the 2009-2010 season (short winter break).

DESIGN

Prospective cohort study.

SETTING

German male professional soccer leagues.

PATIENTS OR OTHER PARTICIPANTS

Seven professional German male soccer teams (184 players in the 2008-2009 season, 188 players in the 2009-2010 season).

MAIN OUTCOME MEASURE(S)

Injury incidences and injury characteristics (cause of injury, location, severity, type, diagnosis), including their monthly distribution, were recorded.

RESULTS

A total of 300 time-loss injuries (2008-2009 n = 151, 2009-2010 n = 149) occurred. The overall injury incidence per 1000 soccer hours was 5.90 (95% confidence interval = 5.03, 6.82) in 2008-2009 and 6.55 (5.58, 7.69) in 2009-2010. Match injuries per 1000 hours were 31.5 (25.0, 38.0) in the first season and 26.5 (20.2, 32.7) in the second season; the corresponding training values were 2.67 (2.08-3.44) and 3.98 (3.19-4.95), respectively. The training injury incidence (incidence rate ratio = 1.49 [95% confidence interval = 1.07, 2.08], P = .02) and the risk of sustaining a knee injury (incidence rate ratio = 1.66 [1.00, 2.76], P = .049) were higher in 2009-2010 after the short winter break; the incidence of moderate and severe injuries (time loss >7 days) trended higher (incidence rate ratio = 1.34 [0.96, 1.86], P = .09).

CONCLUSIONS

Shortening the winter break from 6.5 to 3.5 weeks did not change the overall injury incidence; however, a higher number of training, knee, and possibly more severe injuries (time loss >7 days) occurred.

The preventive effect of the nordic hamstring exercise on hamstring injuries in amateur soccer players: a randomized controlled trial

BACKGROUND

Hamstring injuries are the most common muscle injuries in soccer, and they have a high rate of recurrence. Eccentric hamstrings strength is recognized as an important modifiable risk factor. This led to the development of prevention exercises such as the nordic hamstring exercise (NHE). The effectiveness of the NHE on hamstring injury prevention has never been investigated in amateur soccer.

PURPOSE

To investigate the preventive effect of the NHE on the incidence and severity of hamstring injuries in male amateur soccer players.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Male amateur soccer players (age, mean ± SD, 24.5 ± 3.8 years) from 40 teams were randomly allocated to an intervention (n = 20 teams, 292 players) or control group (n = 20 teams, 287 players). The intervention group was instructed to perform 25 sessions of NHE in a 13-week period. Both the intervention and control groups performed regular soccer training and were followed for hamstring injury incidence and severity during the 2013 calendar year. At baseline, personal characteristics (eg, age, injury history, field position) were gathered from all participants via a questionnaire. Primary outcome was injury incidence. Secondary outcomes were injury severity and compliance with the intervention protocol.

RESULTS

A total of 38 hamstring injuries were recorded, affecting 36 of 579 players (6.2%). The overall injury incidence rate was 0.7 (95% CI, 0.6-0.8) per 1000 player hours, 0.33 (95% CI, 0.25-0.46) in training, and 1.2 (95% CI, 0.82-1.94) in matches. Injury incidence rates were significantly different between the intervention (0.25; 95% CI, 0.19-0.35) and control groups (0.8; 95% CI, 0.61-1.15), χ(2)(1, n = 579) = 7.865; P = .005. The risk for hamstring injuries was reduced in the intervention group compared with the control group (odds ratio, 0.282; 95% CI, 0.110-0.721) and was statistically significant (P = .005). No statistically significant differences were identified between the intervention and control groups regarding injury severity. Compliance with the intervention protocol was 91%.

CONCLUSION

Incorporating the NHE protocol in regular amateur training significantly reduces hamstring injury incidence, but it does not reduce hamstring injury severity. Compliance with the intervention was excellent.

Risk factors for groin injury in sport: an updated systematic review

BACKGROUND

The identification of risk factors for groin injury in sport is important to develop and implement injury prevention strategies.

OBJECTIVE

To identify and evaluate the evidence examining risk factors for groin injury in sport.

MATERIAL AND METHODS

Nine electronic databases were systematically searched to June 2014. Studies selected met the following criteria: original data; analytic design; investigated a risk factor(s); included outcomes for groin injury sustained during sport participation. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed and two independent authors assessed the quality and level of evidence with the Downs and Black (DB) criteria and Oxford Centre of Evidence-Based Medicine model, respectively.

RESULTS

Of 2521 potentially relevant studies, 29 were included and scored. Heterogeneity in methodology and injury definition precluded meta-analyses. The most common risk factors investigated included age, hip range of motion, hip adductor strength and height. The median DB score across studies was 11/33 (range 6-20). The majority of studies represented level 2 evidence (cohort studies) however few considered the inter-relationships between risk factors. There is level 1 and 2 evidence that previous groin injury, higher-level of play, reduced hip adductor (absolute and relative to the hip abductors) strength and lower levels of sport-specific training are associated with increased risk of groin injury in sport.

CONCLUSIONS

We recommended that investigators focus on developing and evaluating preparticipation screening and groin injury prevention programmes through high-quality randomised controlled trials targeting athletes at greater risk of injury.

Management of chronic recurrent osteitis pubis/pubic bone stress in a Premier League footballer: Evaluating the evidence base and application of a nine-point management strategy

BACKGROUND/AIM

The aim of this paper was to use a clinical example to describe a treatment strategy for the management of recurrent chronic groin pain and evaluate the evidence of the interventions.

METHODS

A professional footballer presented with chronic recurrent OP/PBS. The injury was managed successfully with a nine-point programme - 1. Acute pharmacological management. 2. Tone reduction of over-active structures. 3. Improved ROM at hips, pelvis and thorax. 4. Adductor strength. 5. Functional movement assessment. 6. Core stability. 7. Lumbo-pelvic control. 8. Gym-based strengthening. 9. Field-based conditioning/rehabilitation. The evidence for these interventions is reviewed.

RESULTS

The player returned to full training and match play within 41 and 50 days, respectively, and experienced no recurrence of his symptoms in follow up at 13 months.

CONCLUSION

This case report displays a nine-point conservative management strategy for OP/PBS, with non-time dependent clinical objective markers as the progression criteria in a Premier League football player.

Three distinct mechanisms predominate in non-contact anterior cruciate ligament injuries in male professional football players: a systematic video analysis of 39 cases

Background

Current knowledge on anterior cruciate ligament (ACL) injury mechanisms in male football players is limited.

Aim

To describe ACL injury mechanisms in male professional football players using systematic video analysis.

Methods

We assessed videos from 39 complete ACL tears recorded via prospective professional football injury surveillance between 2001 and 2011. Five analysts independently reviewed all videos to estimate the time of initial foot contact with the ground and the time of ACL tear. We then analysed all videos according to a structured format describing the injury circumstances and lower limb joint biomechanics.

Results

Twenty-five injuries were non-contact, eight indirect contact and six direct contact injuries. We identified three main categories of non-contact and indirect contact injury situations: (1) pressing (n=11), (2) re-gaining balance after kicking (n=5) and (3) landing after heading (n=5). The fourth main injury situation was direct contact with the injured leg or knee (n=6). Knee valgus was frequently seen in the main categories of non-contact and indirect contact playing situations (n=11), but a dynamic valgus collapse was infrequent (n=3). This was in contrast to the tackling-induced direct contact situations where a knee valgus collapse occurred in all cases (n=3).

Conclusions

Eighty-five per cent of the ACL injuries in male professional football players resulted from non-contact or indirect contact mechanisms. The most common playing situation leading to injury was pressing followed by kicking and heading. Knee valgus was frequently seen regardless of the playing situation, but a dynamic valgus collapse was rare.

Incidence and severity of reported acute sports injuries in 35 sports using insurance registry data

Acute injuries in sport are still a problem where limited knowledge of incidence and severity in different sports at national level exists. In Sweden, 80% of the sports federations have their mandatory injury insurance for all athletes in the same insurance company and injury data are systematically kept in a national database. The aim of the study was to identify high-risk sports with respect to incidence of acute and severe injuries in 35 sports reported to the database. The number and incidences of injuries as well as injuries leading to permanent medical impairment (PMI) were calculated during 2008-2011. Each year approximately 12,000 injuries and 1,162,660 licensed athletes were eligible for analysis. Eighty-five percent of the injuries were reported in football, ice hockey, floorball, and handball. The highest injury incidence as well as PMI was in motorcycle, handball, skating, and ice hockey. Females had higher risk of a PMI compared with males in automobile sport, handball, floorball, and football. High-risk sports with numerous injuries and high incidence of PMI injuries were motorcycle, handball, ice hockey, football, floorball, and automobile sports. Thus, these sports ought to be the target of preventive actions at national level.

The impact of the FIFA 11+ training program on injury prevention in football players: a systematic review

The FIFA 11+ is a simple, and easy to implement, sports injury prevention program comprising a warm up of 10 conditioning exercises. The aim of this systematic review was to evaluate the impact of the FIFA 11+ on injury incidence, compliance and cost effectiveness when implemented among football players. MEDLINE, EMBASE and Scopus databases were searched using the search terms “FIFA 11+”, “football”, “soccer”, “injury prevention”, and “The 11”. The titles and abstracts were screened by two independent reviewers and the data were filtered by one reviewer using a standardized extraction form and thereafter checked by another one. The risk of bias and the methodological quality of the studies were evaluated through the PEDro score and Critical Appraisal Skills Programme (CASP). A total of 911 studies were identified, of which 12 met the inclusion criteria of the review. The FIFA 11+ has demonstrated how a simple exercise program completed as part of warm-up can decrease the incidence of injuries in amateur football players. In general, considerable reductions in the number of injured players, ranging between 30% and 70%, have been observed among the teams that implemented the FIFA 11+. In addition, players with high compliance to the FIFA 11+ program had an estimated risk reduction of all injuries by 35% and show significant improvements in components of neuromuscular and motor performance when participating in structured warm-up sessions at least 1.5 times/week. Most studies had high methodological quality and a low risk of bias. Given the large number of people who play football at amateur level and the detrimental impact of sports injuries on a personal and societal level, the FIFA 11+ can be considered as a fundamental tool to minimize the risks of participation in a sport with substantial health benefits.

High injury incidence in adolescent female soccer

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

Soccer injuries and recovery in Dutch male amateur soccer players: results of a prospective cohort study

OBJECTIVE

To describe characteristics of outdoor soccer injury and recovery among Dutch soccer players.

DESIGN

Prospective cohort study.

SETTING

The 2009-2010 competitive season (33 weeks).

PARTICIPANTS

Four hundred fifty-six Dutch male soccer players of 23 amateur teams.

MAIN OUTCOME MEASURES

Coaches recorded individual exposure to all soccer activities. Paramedics or sports trainers collected information on the occurrence (e.g., location, type, circumstances) and consequences (eg, absenteeism, medical treatment) of injuries.

RESULTS

In total, 424 time-loss injuries were sustained by 60% (n = 274) of the players, with 23% (n = 105) having more than 1 injury. This corresponds to an overall density of 9.6 (8.7-10.5) injuries per 1000 player hours; 3.9 (3.3-4.7) in training sessions and 20.4 (18.1-23.1) in soccer matches. Almost 30% (n = 123) of the injuries lasted for more than 1 month, 14% (n = 58) were reinjuries (causing longer absence than new injuries), and 54% (n = 230) of the injuries were given medical treatment. The most common diagnoses were muscle/tendon (38%) or joint/ligament injuries (23%) of the lower extremities. After regaining the ability to fully take part in soccer training or matches, 27.4% of the players (n = 116) still reported complaints.

CONCLUSIONS

Two recommendations based on the above-mentioned results are (1) prevention should primarily focus on these most common diagnoses and (2) players resuming soccer activities after an injury should be given special attention to resolve the remaining complaints and to prevent reinjuries.

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

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

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.

Could targeted exercise programmes prevent lower limb injury in community Australian football?

BACKGROUND

Australian football is a popular sport in Australia, at both the community and elite levels. It is a high-speed contact sport with a higher incidence of medically treated injuries when compared with most other organized sports. Hamstring injuries, ligament injuries to the knee or ankle, hip/groin injuries and tendinopathies are particularly common and often result in considerable time lost from sport. Consequently, the prevention of lower limb injuries is a priority for both community and elite Australian football organizations. There is considerable literature available on exercise programmes aimed at reducing lower limb injuries in Australian football and other running-related sports. The quality and outcomes of these studies have varied considerably, but indicate that exercise protocols may be an effective means of preventing lower limb injuries. Despite this, there has been limited high-quality and systematic evaluation of these data.

OBJECTIVE

The aim of this literature review is to systematically evaluate the evidence about the benefits of lower limb injury prevention exercise protocols aimed at reducing the most common severe lower limb injuries in Australian football.

METHODS

The Cochrane Central Register of Controlled Trials, the Cochrane Bone Joint and Muscle Trauma Group Specialized Register, MEDLINE and other electronic databases were searched, from January 1990 to December 2010. Papers reporting the results of randomized controlled trials (RCTs), quasi-RCTs, cohort and case-control studies were extracted. Primary outcomes were injury reduction or risk factor identification and/or modification. Secondary outcomes were adherence to any trialled interventions, injury severity and adverse effects such as secondary injuries and muscle soreness. The methodological quality of extracted manuscripts was assessed and results were collated.

RESULTS

Forty-seven papers were identified and reviewed of which 18 related to hamstring injury, eight related to knee or ankle ligament injury, five related to tendon injury and four were hip or groin injury related. Another 12 papers targeted general lower limb injuries. Most (n = 27 [57%]) were observational studies, investigating injury risk factors. Twenty reported the results of intervention trials. Of these, 15 were efficacy trials reporting the effects of an intervention in reducing injury rates, four were biomechanical interventions in which the impact of the intervention on a known injury risk factor was assessed and one reported changes in injury risk factors as well as injury rates. The strength of the evidence base for exercise programmes for lower limb injury prevention was found to be limited, primarily due to the research methods employed, low adherence to interventions by the study participants and a lack of statistical power. Limited evidence obtained from a small number of RCTs suggests that balance and control exercises might be efficacious in preventing ankle ligament injuries and a programme involving a combination of balance and control exercises, eccentric hamstring, plyometrics and strength exercises could be efficacious in preventing all lower limb injuries.

CONCLUSIONS

Overall, the evidence for exercise programmes as an efficacious lower limb injury prevention strategy is predominantly restricted to studies addressing injury aetiology and mechanisms. The findings of this review highlight the need to develop and test interventions in well designed population-based trials with an emphasis on promoting intervention uptake and adherence and, hence, intervention effectiveness. The results of this review can inform the development of the components of a future lower limb injury prevention exercise protocol for community-level Australian football.

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.

Differences in injury risk and characteristics between Dutch amateur and professional soccer players

OBJECTIVES

To compare the incidence and characteristics of injuries between Dutch amateur and professional male soccer players during one entire competition season.

DESIGN

A prospective two-cohort design.

METHODS

During the 2009-2010 season, 456 Dutch male amateur soccer players and 217 professional players were prospectively followed. Information on injuries and individual exposure to all soccer activities were recorded in both cohorts. Injuries were recorded using the time-loss definition.

RESULTS

In total, 424 injuries were recorded among 274 of the amateur players (60.1% injured players) and 286 injuries were sustained by 136 (62.7% injured players) of the professional players (p=0.52). Compared to the professionals, the injury incidence during training sessions was higher among amateurs (p=0.01), but the injury incidence among professionals was higher during matches (p<0.001). Professional players also had a higher incidence of minimal injuries (p<0.001), whereas the incidence of moderate and severe injuries was higher for amateurs (all p<0.001). Lastly, professional players sustained more overuse injuries (p=0.02), whereas amateurs reported more recurrent injuries (p<0.001).

CONCLUSIONS

The above-mentioned differences in injury rates between amateur and professional players in the Netherlands might be explained by the difference in the level at which they play, since factors like the availability of medical support and/or the team size may influence the injury risk and characteristics.

The preventive effect of the Nordic hamstring exercise on hamstring injuries in amateur soccer players: study protocol for a randomised controlled trial

BACKGROUND

Hamstring injuries are the most common muscle injury in male amateur soccer players and have a high rate of recurrence, often despite extensive treatment and long rehabilitation periods. Eccentric strength and flexibility are recognised as important modifiable risk factors, which have led to the development of eccentric hamstring exercises, such as the Nordic hamstring exercise. As the effectiveness of the Nordic hamstring exercise in reducing hamstring injuries has never been investigated in amateur soccer players, the aim of this study is to investigate the effect of this exercise on the incidence and severity of hamstring injuries in male amateur soccer players. An additional aim is to determine whether flexibility is associated with hamstring injuries.

STUDY DESIGN

Cluster-randomised controlled trial with soccer teams as the unit of cluster.

METHODS

Dutch male amateur soccer players, aged 18-40 years, were allocated to an intervention or control group. Both study groups continued regular soccer training during 2013, but the intervention group additionally performed the Nordic hamstring exercise (25 sessions over 13 weeks). Primary outcomes are the incidence of initial and recurrent hamstring injury and injury severity. Secondary outcomes are hamstring-and-lower-back flexibility and compliance. Compliance to the intervention protocol was also monitored.

DISCUSSION

Eccentric hamstring strength exercises are hypothesised to reduce the incidence of hamstring injury among male amateur soccer players by 70%. The prevention of such injuries will be beneficial to soccer players, clubs, football associations, health insurance companies and society.

TRIAL REGISTRATION

NTR3664.

Mechanisms and risk factors for noncontact ACL injury in age mature athletes who engage in field or court sports: a summary of the literature since 1980

Epidemiological data show that in the last 10 years alone the incidence and rate of anterior cruciate ligament (ACL) injuries have not changed appreciably. Furthermore, many ACL injuries appear to be noncontact in nature and sustained while engaging in some field or court sport. Thus, the need to investigate novel methods and adopt training strategies to prevent ACL injuries is paramount. To do so, however, requires an understanding of the mechanisms and risk factors for the injury. The aim of this review was to investigate the mechanisms and risk factors for noncontact ACL injuries in age mature athletes who compete in field or court sports. A search of the entire MEDLINE database for biomedicine was performed, and an iterative reference check was also conducted. A total of 87 articles disclosed met the eligibility criteria. Articles were grouped into 'themes'; 'anatomical and biomechanical mechanisms and risk factors,' 'intrinsic mechanisms and risk factors,' and 'extrinsic mechanisms and risk factors.' In this review, it is concluded that there are still a number of risk factors and mechanisms for noncontact ACL injury that are not well understood. However, the importance of dynamic knee joint stability is highlighted. It is also suggested that novel methods for preventing ACL injury be investigated and developed.

Psychosocial stress as a predictor of injury in elite junior soccer: a latent growth curve analysis

OBJECTIVES

To investigate by use of a latent growth curve analysis framework whether athletes' individual levels and changes in hassle and uplift levels over a 10-week period could predict injury outcome in an elite junior soccer population.

DESIGN

A prospective design with repeated measurement points.

METHODS

Participants were 101 Swedish elite junior soccer players (67 males and 34 females). Ten sets of measures were taken on a weekly basis during which participants completed the Hassles and Uplifts Scale (HUS). Latent growth curve models were used to examine whether the level and change in psychological stress could predict the frequency of injury over the 10-week period.

RESULTS

The results show that injury occurrence was significantly associated with both the initial level of daily hassle and the change in daily hassle. High initial daily hassle levels and a smaller decrease in daily hassles were associated with injury occurrence. Moreover, injury occurrence was significantly associated with a greater decrease in daily uplift.

CONCLUSIONS

The findings highlight the importance of focusing on state variables using prospective designs and appropriate analysis of within-person change to detect complex and dynamic associations across time in injury-prediction research.

Head and neck injuries in professional soccer

OBJECTIVE

To investigate the rate of and risk factors for head and neck injury in male soccer.

DESIGN

Prospective cohort study.

SETTING

Professional soccer.

PARTICIPANTS

Twenty-six European teams between 2001/2002 and 2009/2010.

ASSESSMENT OF RISK FACTORS

Simple and multiple risk factor analyses were evaluated using Cox regression for player-related variables and logistic regression for match-related variables.

MAIN OUTCOME MEASURES

Injury rate (number of time loss injuries per 1000 hours).

RESULTS

A total of 136 head and neck injuries were recorded (2.2% of all injuries). The head and neck injury rate was 0.17 (0.06 concussions) per 1000 hours. There was a 20-fold higher rate of head and neck injury during match play compared with training (rate ratio [RR], 20.2; 95% confidence interval [CI], 13.3-30.6) and a 78-fold higher rate of concussions (RR, 78.5; 95% CI, 24.4-252.5). Mean layoff for concussion was 10.5 days, but 27% of the concussed players returned to play within 5 days. Defender was the only significant player-related risk factor for head and neck injuries in the multiple analysis (RR, 1.8; 95% CI, 1.0-3.1), whereas no significant variables were identified for concussions.

CONCLUSIONS

Head and neck injuries were relatively uncommon in professional soccer. Defender was the playing position most at risk. More than one-quarter of the concussed players returned to play before what is recommended in the consensus statements by the major sports governing bodies.

Upper extremity injuries in male elite football players

PURPOSE

To investigate the epidemiology of upper extremity injuries in male elite football players and to describe their characteristics, incidence and lay-off times.

METHODS

Between 2001 and 2011, 57 male European elite football teams (2,914 players and 6,215 player seasons) were followed prospectively. Time-loss injuries and exposure to training and matches were recorded on individual basis.

RESULTS

In total, 11,750 injuries were recorded, 355 (3 %) of those affected the upper extremities giving an incidence of 0.23 injuries/1,000 h of football. The incidence in match play was almost 7 times higher than in training (0.83 vs. 0.12 injuries/1,000 h, rate ratio 6.7, 95 % confidence interval 5.5-8.3). As much as 32 % of traumatic match injuries occurred as a result of foul play situations. Goalkeepers had a significantly higher incidence of upper extremity injuries compared to outfield players (0.80 vs. 0.16 injuries/1,000 h, rate ratio 5.0, 95 % confidence interval 4.0-6.2). The average absence due to an upper extremity injury was 23 ± 34 days.

CONCLUSIONS

Upper extremity injuries are uncommon among male elite football players. Goalkeepers, however, are prone to upper extremity injury, with a five times higher incidence compared to outfield players.

LEVEL OF EVIDENCE

II.

Femoroacetabular impingement in a professional soccer player

Presented is the case of a 25-year-old professional soccer player with a long-standing history of hip injuries, including a hamstring injury, adductor partial tearing with surgical release and labral tearing in the hip joint. The patient was eventually found to have a mixed type femoracetabular impingement and adaptive bony changes of the hip. The patient was treated with an arthroscopic acetabuloplasty of the pincer lesion, femoroplasty for the treatment of the cam lesion and labral repair along with open proximal adductor repair to restore the native biomechanics of the hip.

LEVEL OF EVIDENCE

V.