***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 STUDY DESIGN Controlled single-group pretest/posttest design . OBJECTIVE The purpose of this study was to determine if a 6-week neuromuscular training program design ed to decrease the incidence of anterior cruciate ligament ( ACL ) injuries would improve single-limb postural stability in young female athletes . We hypothesized neuromuscular training would result in an improvement in postural stability , with the greatest improvement taking place in the medial-lateral direction . BACKGROUND Balance training has become a common component of programs design ed to prevent ACL injury . Rehabilitation programs can improve postural stability following ACL injury and reconstruction ; however , there is limited information available which quantifies improvement of postural stability following neuromuscular training design ed to prevent ACL injuries in a healthy population . METHODS AND MEASURES Forty-one healthy female high school athletes ( mean age , 15.3 years ; age range , 13 - 17 years ) participated in this study . Single-limb postural stability for both lower extremities was assessed with a Biodex Stability System . The neuromuscular training program consisted of three 90-minute training sessions per week for 6 weeks . Following the completion of the training program , each subject was re-evaluated to determine change in total , anterior-posterior , and medial-lateral single-limb stability . Two-way analysis of variance models were used to determine differences between pretraining and posttraining and between limbs . RESULTS The subjects showed a significant improvement in single-limb total stability ( P = .004 ) and anterior-posterior stability ( P = .001 ) , but not medial-lateral stability ( P = .650 ) for both the right and left lower extremity following training . In addition , the subjects demonstrated significantly better total postural stability on the right side as compared to the left ( P = .026 ) . CONCLUSIONS A 6-week neuromuscular training program design ed to decrease the incidence of ACL injuries improves objective measures of total and anterior-posterior single-limb postural stability in high school female athletes Background : Sport is the leading cause of injury requiring medical attention among adolescents . We studied the effectiveness of a home-based balance-training program using a wobble board in improving static and dynamic balance and reducing sports-related injuries among healthy adolescents . Methods : In this cluster r and omized controlled trial , we r and omly selected 10 of 15 high schools in Calgary to participate in the fall of 2001 . We then recruited students from physical education classes and r and omly assigned them , by school , to either the intervention ( n = 66 ) or the control ( n = 61 ) group . Students in the intervention group participated in a daily 6-week and then a weekly 6-month home-based balance-training program using a wobble board .  Students at the control schools received testing only . The primary outcome measures were timed static and dynamic balance , 20-m shuttle run and vertical jump , which were measured at baseline and biweekly for 6 weeks . Self-reported injury data were collected over the 6-month follow-up period . Results : At 6 weeks , improvements in static and dynamic balance were observed in the intervention group but not in the control group ( difference in static balance 20.7 seconds , 95 % confidence interval [ CI ] 10.8 to 30.6 seconds ; difference in dynamic balance 2.3 seconds , 95 % CI 0.7 to 4.0 seconds ) . There was evidence of a protective effect of balance training in over 6 months ( relative risk of injury 0.2 , 95 % CI 0.05 to 0.88 ) . The number needed to treat to avoid 1 injury over 6 months was 8 ( 95 % CI 4 to 35 ) . Interpretation : Balance training using a wobble board is effective in improving static and dynamic balance and reducing sports-related injuries among healthy adolescents Purpose We aim ed 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 aim ed 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 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 Purpose The study investigated the effects of FIFA 11 + and HarmoKnee , both being popular warm-up programs , on proprioception , and on the static and dynamic balance of professional male soccer players . Methods Under 21 year-old soccer players ( n = 36 ) were divided r and omly into 11 + , HarmoKnee and control groups . The programs were performed for 2 months ( 24 sessions ) . Proprioception was measured bilaterally at 30 ° , 45 ° and 60 ° knee flexion using the Biodex Isokinetic Dynamometer  . Static and dynamic balances were evaluated using the stork st and test and Star Excursion Balance Test ( SEBT ) , respectively . Results The proprioception error of dominant leg significantly decreased from pre- to post-test by 2.8 % and 1.7 % in the 11 + group at 45 ° and 60 ° knee flexion , compared to 3 % and 2.1 % in the HarmoKnee group . The largest joint positioning error was in the non-dominant leg at 30 ° knee flexion ( mean error value = 5.047 ) , ( p<0.05 ) . The static balance with the eyes opened increased in the 11 + by 10.9 % and in the HarmoKnee by 6.1 % ( p<0.05 ) . The static balance with eyes closed significantly increased in the 11 + by 12.4 % and in the HarmoKnee by 17.6 % . The results indicated that static balance was significantly higher in eyes opened compared to eyes closed ( p = 0.000 ) . Significant improvements in SEBT in the 11 + ( 12.4 % ) and HarmoKnee ( 17.6 % ) groups were also found . Conclusion Both the 11 + and HarmoKnee programs were proven to be useful warm-up protocol s in improving proprioception at 45 ° and 60 ° knee flexion as well as static and dynamic balance in professional male soccer players . Data from this research may be helpful in encouraging coaches or trainers to implement the two warm-up programs in their soccer teams Background : Field expedient screening tools that can identify individuals at an elevated risk for injury are needed to minimize time loss in American football players . Previous research has suggested that poor dynamic balance may be associated with an elevated risk for injury in athletes ; however , this has yet to be examined in college football players . Hypothesis : To determine if dynamic balance deficits are associated with an elevated risk of injury in collegiate football players . It was hypothesized that football players with lower performance and increased asymmetry in dynamic balance would be at an elevated risk for sustaining a noncontact lower extremity injury . Study Design : Prospect i ve cohort study . Methods : Fifty-nine collegiate American football players volunteered for this study . Demographic information , injury history , and dynamic balance testing performance were collected , and noncontact lower extremity injuries were recorded over the course of the season . Receiver operator characteristic curves were calculated based on performance on the Star Excursion Balance Test ( SEBT ) , including composite score and asymmetry , to determine the population -specific risk cut-off point . Relative risk was then calculated based on these variables , as well as previous injury . Results : A cut-off point of 89.6 % composite score on the SEBT optimized the sensitivity ( 100 % ) and specificity ( 71.7 % ) . A college football player who scored below 89.6 % was 3.5 times more likely to get injured . Conclusion : Poor performance on the SEBT may be related to an increased risk for sustaining a noncontact lower extremity injury over the course of a competitive American football season . Clinical Relevance : College football players should be screened preseason using the SEBT to identify those at an elevated risk for injury based upon dynamic balance performance to implement injury mitigation strategies to this specific subgroup of athletes 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 
    Output:
    
Conclusions : FIFA 11 can be considered as a tool to reduce the risk of injury .
It may improve dynamic balance and agility and can be considered for inclusion in the training of football players