***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background A protective effect on injury risk in youth sports through neuromuscular warm-up training routines has consistently been demonstrated . However , there is a paucity of information regarding the quantity and quality of coach-led injury prevention programmes and its impact on the physical performance of players . Objective The aim of this cluster-r and omised controlled trial was to assess whether different delivery methods of an injury prevention programme ( FIFA 11 + ) to coaches could improve player performance , and to examine the effect of player adherence on performance and injury risk . Method During the 2011 football season ( May – August ) , coaches of 31 tiers 1–3 level teams were introduced to the 11 + through either an unsupervised website or a coach-focused workshop with and without additional on-field supervisions . Playing exposure , adherence to the 11 + , and injuries were recorded for female 13-year-old to 18-year-old players . Performance testing included the Star Excursion Balance Test ( SEBT ) , single-leg balance , triple hop and jumping-over-a-bar tests . Results Complete preseason and postseason performance tests were available for 226 players ( 66.5 % ) . Compared to the unsupervised group , single-leg balance ( OR=2.8 ; 95 % CI 1.1 to 4.6 ) and the anterior direction of the SEBT improved significantly in the onfield supervised group of players ( OR=4.7 ; 95 % CI 2.2 to 7.1 ) , while 2-leg jumping performance decreased ( OR=−5.1 ; 95 % CI −9.9 to −0.2 ) . However , significant improvements in 5 of 6 reach distances in the SEBT were found , favouring players who highly adhered to the 11 + . Also , injury risk was lower for those players ( injury rate ratio , IRR=0.28 , 95 % CI 0.10 to 0.79 ) . Conclusions Different delivery methods of the FIFA 11 + to coaches influenced players ’ physical performance minimally . However , high player adherence to the 11 + result ed in significant improvements in functional balance and reduced injury risk Objective To evaluate the effectiveness of neuromuscular training in reducing the rate of acute knee injury  in adolescent female football players . Design Stratified cluster r and omised controlled trial with clubs as the unit of r and omisation . Setting 230 Swedish football clubs ( 121 in the intervention group , 109 in the control group ) were followed for one season ( 2009 , seven months ) . Participants 4564 players aged 12 - 17 years ( 2479 in the intervention group , 2085 in the control group ) completed the study . Intervention 15 minute neuromuscular warm-up programme ( targeting core stability , balance , and proper knee alignment ) to be carried out twice a week throughout the season . Main outcome measures The primary outcome was rate of anterior cruciate ligament injury ; secondary outcomes were rates of severe knee injury ( > 4 weeks ’ absence ) and any acute knee injury . Results Seven players ( 0.28 % ) in the intervention group , and 14 ( 0.67 % ) in the control group had an anterior cruciate ligament injury . By Cox regression analysis according to intention to treat , a 64 % reduction in the rate of anterior cruciate ligament injury was seen in the intervention group ( rate ratio 0.36 , 95 % confidence interval 0.15 to 0.85 ) . The absolute rate difference was −0.07 ( 95 % confidence interval −0.13 to 0.001 ) per 1000 playing hours in favour of the intervention group . No significant rate reductions were seen for secondary outcomes . Conclusions A neuromuscular warm-up programme significantly reduced the rate of anterior cruciate ligament injury in adolescent female football players . However , the absolute rate difference did not reach statistical significance , possibly owing to the small number of events . Trial registration Clinical trials NCT00894595 Groin injuries cause major problems in sports and particularly in football . Exercise is effective in treating adductor-related groin pain , but no trials have been published regarding the specific prevention of groin pain or prevention specifically targeting overuse injuries in sport using exercise programs . We performed a cluster-r and omized trial including 55 football clubs representing 1211 players . The clubs were r and omized to an exercise program aim ed at preventing groin injuries ( n=27 ) or to a control group training as usual ( n=28 ) . The intervention program consisted of six exercises including strengthening ( concentric and eccentric ) , coordination , and core stability exercises for the muscles related to the pelvis . Physiotherapists assigned to each club registered all groin injuries . Twenty-two clubs in each group completed the study , represented by 977 players . There was no significant effect of the intervention ( HR=0.69 , 95 % CI 0.40 - 1.19 ) . The risk of a groin injury was reduced by 31 % , but this reduction was not significant . A univariate analysis showed that having had a previous groin injury almost doubles the risk of developing a new groin injury and playing at a higher level almost triples the risk of developing a groin injury Background The incidence rate of soccer injuries is among the highest in sports , particularly for adult male soccer players . Purpose To investigate the effect of the ‘ The11 ’ injury prevention programme on injury incidence and injury severity in adult male amateur soccer players . Study design Cluster-r and omised controlled trial . Methods Teams from two high-level amateur soccer competitions were r and omly assigned to an intervention ( n=11 teams , 223 players ) or control group ( n=12 teams , 233 players ) . The intervention group was instructed to perform The11 in each practice session during one soccer season . The11 focuses on core stability , eccentric training of thigh muscles , proprioceptive training , dynamic stabilisation and plyometrics with straight leg alignment . All participants of the control group continued their practice sessions as usual . Results In total , 427 injuries were recorded , affecting 274 of 456 players ( 60.1 % ) .  Compliance with the intervention programme was good ( team compliance=73 % , player compliance=71 % ) . Contrary to the hypothesis , injury incidences were almost equal between the two study groups : 9.6 per 1000 sports hours ( 8.4–11.0 ) for the intervention group and 9.7 ( 8.5–11.1 ) for the control group . No significant differences were found in injury severity , but a significant difference was observed in the location of the injuries : players in the intervention group sustained significantly less knee injuries . Conclusions This study did not find significant differences in the overall injury incidence or injury severity between the intervention and control group of adult male soccer players . More research is recommended , focusing on injury aetiology and risk factors in adult male amateur soccer players Objective To examine the effect of a comprehensive warm-up programme design ed to reduce the risk of injuries in female youth football . Design Cluster r and omised controlled trial with clubs as the unit of r and omisation . Setting 125 football clubs from the south , east , and middle of Norway ( 65 clusters in the intervention group ; 60 in the control group ) followed for one league season ( eight months ) . Participants 1892 female players aged 13 - 17 ( 1055 players in the intervention group ; 837 players in the control group ) . Intervention A comprehensive warm-up programme to improve strength , awareness , and neuromuscular control during static and dynamic movements . Main outcome measure Injuries to the lower extremity ( foot , ankle , lower leg , knee , thigh , groin , and hip ) . Results During one season , 264 players had relevant injuries  : 121 players in the intervention group and 143 in the control group ( rate ratio 0.71 , 95 % confidence interval 0.49 to 1.03 ) . In the intervention group there was a significantly lower risk of injuries overall ( 0.68 , 0.48 to 0.98 ) , overuse injuries ( 0.47 , 0.26 to 0.85 ) , and severe injuries ( 0.55 , 0.36 to 0.83 ) . Conclusion Though the primary outcome of reduction in lower extremity injury did not reach significance , the risk of severe injuries , overuse injuries , and injuries overall was reduced . This indicates that a structured warm-up programme can prevent injuries in young female football players . Trial registration IS RCT N10306290 QUESTION Is an injury prevention program consisting of 10 exercises design ed to improve stability , muscle strength , co-ordination , and flexibility of the trunk , hip and leg muscles ( known as The11 ) cost effective in adult male amateur soccer players ? DESIGN Cost-effectiveness analysis of a cluster-r and omised controlled trial . PARTICIPANTS 479 adult male amateur soccer players aged 18 - 40 years . INTERVENTION The intervention group was instructed to perform the exercises at each training session ( 2 to 3 sessions per week ) during one soccer season . The exercises focus on core stability , eccentric training of thigh muscles , proprioceptive training , dynamic stabilisation , and plyometrics with straight leg alignment . The control group continued their usual warm-up . OUTCOME MEASURES All injuries and costs associated with these injuries were compared between groups after bootstrapping ( 5000 replications ) . RESULTS No significant differences in the proportion of injured players and injury rate were found between the two groups . Mean overall costs in the intervention group were € 161 ( SD 447 ) per athlete and € 256 ( SD 555 ) per injured athlete . Mean overall costs in the control group were € 361 ( SD 1529 ) per athlete and € 606 ( SD 1944 ) per injured athlete . Statistically significant cost differences in favour of the intervention group were found per player ( mean difference € 201 , 95 % CI 15 to 426 ) and per injured player ( mean difference € 350 , 95 % CI 51 to 733 ) . CONCLUSIONS The exercises failed to significantly reduce the number of injuries in male amateur soccer players within one season , but did significantly reduce injury-related costs . The cost savings might be the result of a preventive effect on knee injuries , which often have substantial costs due to lengthy rehabilitation and lost productivity . TRIAL REGISTRATION NTR2416 The injury rate in football is high , and effective injury prevention methods are needed . An exercise program , the " 11 , " has been design ed to prevent the most common injury types in football . However , the effect of such a program on performance is not known . The aim of this r and omized-controlled trial was to investigate the effect of the " 11 " on performance after a 10-week training period . Thirty-four adolescent female football players were r and omly assigned to either an intervention ( n=18 ) or a control group ( n=16 ) . The " 11 " is a 15-min program consisting of ten exercises for core stability , lower extremity strength , balance and agility . Performance tests included isokinetic and isometric strength protocol s for the quadriceps and hamstrings , isometric hip adduction and abduction strength , vertical jump tests , sprint running and soccer skill tests . There was no difference between the intervention and control groups in the change in performance from the pre- to post-test for any of the tests used . In conclusion , no effect was observed on a series of performance tests in a group of adolescent female football players using the " 11 "  as a structured warm-up program Background : Risk factors for soccer injuries and possibilities for prevention have been discussed by several authors , but only a few have investigated the effectiveness of preventive interventions . Purpose : The aim of the present study was to evaluate the effects of a prevention program on the incidence of soccer injuries in male youth amateur players . Study Design : Prospect i ve controlled intervention study . Methods : Seven soccer teams took part in a  prevention program that focused on education and supervision of coaches and players , while seven other teams were instructed to train and play soccer as usual . Over 1 year all injuries were documented weekly by physicians . Complete weekly injury reports were available for 194 players . Results : The incidence of injury per 1000 hours of training and playing soccer was 6.7 in the intervention group and 8.5 in the control group , which equates to 21 % fewer injuries in the intervention group . The greatest effects were observed for mild injuries , overuse injuries , and injuries incurred during training . The prevention program had greater effects in low-skill than in high-skill teams . Conclusions : The incidence of soccer injuries can be reduced by preventive interventions , especially in low skill level youth teams . Coaches and players need better education regarding injury prevention strategies and should include such interventions as part of their regular training A set of exercises -- the " 11"--have been selected to prevent football injuries . The purpose of this cluster-r and omized controlled trial was to investigate the effect of the " 11 " on injury risk in female youth football . Teams were r and omized to an  intervention ( n=59 teams , 1091 players ) or a control group ( n=54 teams , 1001 players ) . The intervention group was taught the " 11 , " exercises for core stability , lower extremity strength , neuromuscular control and agility , to be used as a 15-min warm-up program for football training over an 8-month season . A total of 396 players ( 20 % ) sustained 483 injuries . No difference was observed in the overall injury rate between the intervention ( 3.6 injuries/1000 h , confidence interval ( CI ) 3.2 - 4.1 ) and control group ( 3.7 , CI 3.2 - 4.1 ; RR=1.0 , CI 0.8 - 1.2 ; P=0.94 ) nor in the incidence for any type of injury . During the first 4 months of 
    Output:
    
Conclusions This systematic review and meta- analysis indicated that use of F-MARC injury prevention programs , particularly the ‘ 11 + ’ program , decreases the risk of injuries among soccer players .