***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 : 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 Objective —To determine whether protective headgear reduced the incidence of concussion in a pilot study of under 15 rugby union . Methods —Sixteen under 15 rugby union teams were recruited from three interschool competitions in metropolitan Sydney and the adjacent country region . A prospect i ve study was undertaken over a single competitive season . The study had two arms : a headgear arm and a control arm . Headgear wearing rates and injury data were reported to the investigators and verified using spot checks . Results —A total of 294 players participated in the study . There were 1179 player exposures with headgear and 357 without headgear . In the study time frame , there were nine incidences of concussion ; seven of the players involved wore headgear and two did not . There was no significant difference between concussion rates between the two study arms . Conclusions —Although there is some controversy about the desirability of wearing protective headgear in football , this pilot study strongly suggests that current headgear does not provide significant protection against concussion in rugby union at a junior level Background : Ankle sprains are the most common form of acute injury in volleyball . A prevention programme consisting of technical training , proprioceptive training , and external support was previously design ed to reduce the rate of ankle sprains in volleyball players . Objective : To investigate which of these three interventions is the most effective in preventing ankle sprain in female volleyball players . Methods : Participants were 52 players who suffered ankle sprains during the season 1998–1999 . They were divided r and omly into three preventive groups : group 1 ( n = 18 ) followed the technical training programme ; group 2 ( n = 17 ) followed the proprioceptive programme ; group 3 ( n = 17 ) used orthosis . The players followed their respective programmes for the whole of the 1999–2000 season . Data were collected at the end of the season . Results : The three preventive strategies were all effective in preventive further ankle sprain .  Technical training was slightly more effective than the other two methods . Orthosis was not effective in athletes who had suffered ankle sprains more than three times during their careers . Under those circumstances , technical training and proprioceptive training were equally effective at preventive further sprains . Conclusions : Technical training and proprioceptive training are effective methods of preventing ankle sprain in volleyball players who have suffered this injury four or more times during their career . Orthosis appears effective only in players with fewer than four previous sprains 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 To prospect ively evaluate the effect of neuromuscular training on the incidence of knee injury in female athletes , we monitored two groups of female athletes , one trained before sports participation and the other not trained , and a group of untrained male athletes throughout the high school soccer , volleyball , and basketball seasons . Weekly reports included the number of practice and competition exposures and mechanism of injury . There were 14 serious knee injuries in the 1263 athletes tracked through the study . Ten of 463 untrained female athletes sustained serious knee injuries ( 8 noncontact ) , 2 of 366 trained female athletes sustained serious knee injuries ( 0 noncontact ) , and 2 of 434 male athletes sustained serious knee injuries ( 1 noncontact ) . The knee injury incidence per 1000 athlete-exposures was 0.43 in untrained female athletes , 0.12 in trained female athletes , and 0.09 in male athletes ( P 0.02 , chi-square analysis ) . Untrained female athletes had a 3.6 times higher incidence of knee injury than trained female athletes ( P 0.05 ) and 4.8 times higher than male athletes ( P 0.03 ) . The incidence of knee injury in trained female athletes was not significantly different from that in untrained male athletes ( P 0.86 ) . The difference in the incidence of noncontact injuries between the female groups was also significant ( P 0.01 ) . This prospect i ve study demonstrated a decreased incidence of knee injury  in female athletes after a specific plyometric training program Abstract Objective To investigate the effect of a structured warm-up programme design ed to reduce the incidence of knee and ankle injuries in young people participating in sports . Design Cluster r and omised controlled trial with clubs as the unit of r and omisation . Setting 120 team h and ball clubs from central and eastern Norway ( 61 clubs in the intervention group , 59 in the control group ) followed for one league season ( eight months ) . Participants 1837 players aged 15 - 17 years ; 958 players ( 808 female and 150 male ) in the intervention group ; 879 players ( 778 female and 101 male ) in the control group . Intervention A structured warm-up programme to improve running , cutting , and l and ing technique as well as neuromuscular control , balance , and strength . Main outcome measure The rate of acute injuries to the knee or ankle . Results During the season , 129 acute knee or ankle injuries occurred , 81 injuries in the control group ( 0.9 ( SE 0.09 ) injuries per 1000 player hours ; 0.3 ( SE 0.17 ) in training v 5.3 ( SE 0.06 ) during matches ) and 48 injuries in the intervention group ( 0.5 ( SE 0.11 ) injuries per 1000 player hours ; 0.2 ( SE 0.18 ) in training v 2.5 ( SE 0.06 ) during matches ) . Fewer injured players were in the intervention group than in the control group ( 46 ( 4.8 % ) v ( 76 ( 8.6 % ) ; relative risk intervention group v control group 0.53 , 95 % confidence interval 0.35 to 0.81 ) . Conclusion A structured programme of warm-up exercises can prevent knee and ankle injuries in young people playing sports . Preventive training should therefore be introduced as an integral part of youth sports programmes Proprioceptive training has been shown to reduce the incidence of ankle sprains in different sports . It can also improve rehabilitation after anterior cruciate ligament ( ACL ) injuries whether treated operatively or nonoperatively . Since ACL injuries lead to long absence from sports and are one of the main causes of permanent sports disability , it is essential to try to prevent them . In a prospect i ve controlled study of 600 soccer players in 40 semiprofessional or amateur teams , we studied the possible preventive effect of a gradually increasing proprioceptive training on four different types of wobble-boards during three soccer seasons . Three hundred players were instructed to train 20 min per day with 5 different phases of increasing difficulty . The first phase consisted of balance training without any balance board ; phase 2 of training on a rectangular balance board ; phase 3 of training on a round board ; phase 4 of training on a combined round and rectangular board ; phase 5 of training on a so-called BABS board .  A control group of 300 players from other , comparable teams trained “ normally ” and received  no special balance training . Both groups were observed for three whole soccer seasons , and possible ACL lesions were diagnosed by clinical examination , KT-1000 measurements , magnetic resonance imaging or computed tomography , and arthroscopy . We found an incidence of 1.15 ACL injuries per team per year in the control group and 0.15 injuries per team per year in the proprioceptively trained group ( P<0.001 ) . Proprioceptive training can thus significantly reduce the incidence of ACL injuries in soccer players Objectives : To document the effects of compulsory mouthguard wearing on rugby related dental injury cl aims made to ACC , the administrator of New Zeal and ’s accident compensation scheme . Methods : An ecological study was conducted . Estimates of mouthguard wearing rates were available from prospect i ve studies conducted in 1993 , 2002 , and 2003 . Rugby related dental injury cl aims were available for the period 1995–2003 . Player numbers were available from 1998 .  Mouthguard wearing was made compulsory during match play for rugby players at under 19 level and below at the beginning of the 1997 season , and for all grade s of domestic rugby at the beginning of the 1998 season . Greater powers of enforcement were provided to referees at the beginning of the 2003 season . Results : The self reported rate of mouthguard use was 67 % of player-weeks in 1993 and 93 % in 2003 . A total of 2644 cl aims was reported in 1995 . There was a 43 % ( 90 % confidence interval 39 % to 46 % ) reduction in dental cl aims from 1995 to 2003 . On the reasonable assumption that the number of players and player-matches remained constant throughout the study period , the relative rate of injury cl aims for non-wearers versus wearers was 4.6 ( 90 % confidence interval 3.8 to 5.6 ) . The cumulative savings in cl aim costs compared with the cost per year if cl aim numbers had remained constant from 1995 is $ 1.87 million NZD . Conclusion : Although ecological studies have acknowledged weaknesses , the findings provide evidence that mouthguard use is a simple and effective injury prevention strategy for rugby players . The use of mouthguards for all players in both matches and contact practice situations is strongly recommended 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 PURPOSE To evaluate the 
    Output:
    
It can be concluded that injury prevention strategies that focus on preseason conditioning , functional training , education , balance and sport-specific skills , which should be continued throughout the sporting season , are effective .