***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: Abstract . This prospect i ve r and omized intervention investigated whether training on a balance board could reduce the amount of traumatic injuries of the lower extremities in female soccer players . A total of 221 female soccer players from 13 different teams playing in the second and third Swedish divisions volunteered to participate in the study . Seven teams ( n=121 ) were r and omized to an intervention group and six teams ( n=100 ) to a control group and were followed during one outdoor season ( April – October ) . Before and after the season muscle flexibility and balance/postural sway of the lower extremities were measured in the players . There were no significant differences in age , height , weight , muscle flexibility and balance/postural sway of the lower extremities between the intervention and the control group . During the season the players in the intervention group performed a special training program consisting of 10–15 min of balance board training in addition to their st and ard soccer practice and games . After a 37 % drop-out the intervention group consisted of 62 players and the control group of 78 players . The results showed no significant differences between the groups with respect either to the number , incidence , or type of traumatic injuries of the lower extremities . The incidence rate of " major " injuries was higher in the intervention group than in the control group . Four of five anterior cruciate ligament injuries occurred in the intervention group , which means that we could not prevent severe knee injuries in female soccer players with balance board training . However , among the players who had been injured during the 3-month period prior to this investigation there were significantly more players from the control group than from the intervention group who sustained new injuries during the study period 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 Background : Anterior knee pain ( AKP ) is the most common activity-related injury of the knee . The authors investigated the effect of an exercise intervention on the incidence of AKP in UK army recruits undergoing a 14-week physically arduous training program . Hypothesis : Modifying military training to include targeted preventative exercises may reduce the incidence of AKP in a young recruit population . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : A single-blind cluster r and omized controlled trial was performed in 39 male and 11 female training groups ( median age : 19.7 years ; interquartile range , 17 - 25 ) undergoing phase 1 of army recruit training . Each group was r and omly assigned to either an intervention ( n = 759 ) or control ( n = 743 ) protocol . The intervention consisted of 4 strengthening and 4 stretching exercises completed during supervised physical training lessons ( 7 per week ) . The control group followed the existing training syllabus warm-up exercises . The primary outcome was a diagnosis of AKP during the 14-week training program . Results : Forty-six participants ( 3.1 % ; 95 % confidence interval [ CI ] , 2.3 - 4.1 ) were diagnosed with AKP . There were 36 ( 4.8 % ; 95%CI , 3.5 - 6.7 ) new cases of AKP in the control group and 10 ( 1.3 % ; 0.7 - 2.4 ) in the intervention group . There was a 75 % reduction in AKP risk in the intervention group ( unadjusted hazard ratio = 0.25 ; 95 % CI , 0.13 - 0.52 ; P < .001 ) . Three participants ( 0.4 % ) from the intervention group were discharged from the military for medical reasons compared to 25 ( 3.4 % ) in the control group . Conclusion : A simple set of lower limb stretching and strengthening exercises result ed in a substantial and safe reduction in the incidence of AKP in a young military population undertaking a physical conditioning program . Such exercises could also be beneficial for preventing this common injury among nonmilitary participants in recreational physical activity Background Participants ' compliance , attitudes and beliefs have the potential to influence the efficacy of an intervention greatly . Objective To characterise team and player compliance with a comprehensive injury prevention warm-up programme for football ( The 11 + ) , and to assess attitudes towards injury prevention among coaches and their association with compliance and injury risk . Study Design A prospect i ve cohort study and retrospective survey based on a cluster-r and omised controlled trial with teams as the unit of r and omisation . Methods Compliance , exposure and injuries were registered prospect ively in 65 of 125 football teams ( 1055 of 1892 female Norwegian players aged 13–17 years and 65 of 125 coaches ) throughout one football season ( March – October 2007 ) . St and ardised telephone interviews were conducted to assess coaches ' attitudes towards injury prevention . Results Teams completed the injury prevention programme in 77 % ( mean 1.3 sessions per week ) of all training and match sessions , and players in 79 % ( mean 0.8 sessions per week ) of the sessions they attended . Compared with players with intermediate compliance , players with high compliance with the programme had a 35 % lower risk of all injuries ( RR 0.65 , 95 % CI 0.46 to 0.91 , p=0.011 ) . Coaches who had previously utilised injury prevention training coached teams with a 46 % lower risk of injury ( OR 0.54 , 95 % CI 0.33 to 0.87 , p=0.011 ) . Conclusions Compliance with the injury prevention programme was high , and players with high compliance had significantly lower injury risk than players with intermediate compliance . Positive attitudes towards injury prevention correlated with high compliance and lower injury risk 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 Young female players in European h and ball have a very high injury incidence , up to 50 injuries per 1000 hours of game . More than half of these injuries happen without any external cause . The aim of the study was to investigate the effect of an intervention programme design ed to reduce the number of injuries in young female players in European h and ball , with special emphasis on injuries in the lower extremities . The programme was created using elite athlete training programmes and those design ed for rehabilitation of injured athletes with functional instability of their ankles and rupture of the anterior cruciate ligament . It included the use of an ankle disk for 10 - 15 min at all practice sessions , for one 10-month season ( August 1995-May 1996 ) . Twenty-two teams participated in the study , and were r and omly assigned to the intervention or control group . Eleven teams with 111 players were r and omised to the intervention group and 11 teams with 126 players to the control group . Data were analysed using a t-test for continuous variables , chi2- analysis and Fisher 's exact test for dichotomous variables and multivariate methods to determine odds-ratios . The results indicated that using the intervention programme decreased the numbers of both traumatic and overuse injuries significantly . The differences in injuries between the groups were 80 % during games and 71 % during practice . In addition , the players in the control group had a 5.9 times higher risk of acquiring an injury than the players in the intervention group 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 Background It is unknown whether an exercise program can prevent  overuse injuries in the lower extremity . An often encountered and important risk factor for the development of lower extremity overuse injuries is an abrupt increase in activity level . Hypothesis A preventive training program based on a literature review of intrinsic risk factors , and performed concurrent with an increase in physical activity , can reduce the incidence of overuse 
    Output:
    
Intention-to-treat sensitivity analyses consistently revealed even more robust effect estimates .
Despite a few outlying studies , consistently favourable estimates were obtained for all injury prevention measures except for stretching .
Strength training reduced sports injuries to less than 1/3 and overuse injuries could be almost halved