***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 Valid , reliable and responsive Patient-Reported Outcome ( PRO ) question naires for young to middle-aged , physically active individuals with hip and groin pain are lacking . Objective To develop and vali date a new PRO in accordance with the COnsensus-based St and ards for the selection of health Measurement INstruments ( COSMIN ) recommendations for use in young to middle-aged , physically active patients with long-st and ing hip and /or groin pain . Methods Preliminary patient interviews ( content validity ) included 25 patients .  Validity , reliability and responsiveness were evaluated in a clinical study including 101 physically active patients ( 50 women ) ; mean age 36 years , range 18–63 years . Results The Copenhagen Hip and Groin Outcome Score ( HAGOS ) consists of six separate subscales assessing Pain , Symptoms , Physical function in daily living , Physical function in Sport and Recreation , Participation in Physical Activities and hip and /or groin-related Quality of Life ( QOL ) . Test – retest reliability was substantial , with intraclass correlation coefficients ranging from 0.82 to 0.91 for the six subscales . The smallest detectable change ranged from 17.7 to 33.8 points at the individual level and from 2.7 to 5.2 points at the group level for the different subscales . Construct validity and responsiveness were confirmed with statistically significant correlation coefficients ( 0.37–0.73 , p < 0.01 ) for convergent construct validity and for responsiveness from 0.56 to 0.69 , p < 0.01 . Conclusion HAGOS has adequate measurement qualities for the assessment of symptoms , activity limitations , participation restrictions and QOL in physically active , young to middle-aged patients with long-st and ing hip and /or groin pain and is recommended for use in interventions where the patient 's perspective and health-related QOL are of primary interest . Trial registration Clinical Trials.gov Background Little is known about the influence of compliance with neuromuscular training ( NMT ) on the  knee injury rate in football . Aim To evaluate team and player compliance with an NMT programme in adolescent female football and to study the association between compliance and acute knee injury rates . Methods Prospect i ve cohort study based on a cluster r and omised controlled trial on players aged 12–17 years with 184 intervention teams ( 2471 players ) and 157 control teams ( 2085 players ) .  Exposure and acute time loss knee injuries were recorded . Team and player compliance was recorded by the coaches on a player attendance form . The intervention group was divided into tertiles of compliance . Injury rates were compared by calculating rate ratios ( RRs ) and 95 % CIs using exact Poisson tests with the low-compliance tertile as reference . Seasonal compliance trends were analysed using linear regression . Results Players in the high-compliance tertile had an 88 % reduction in the anterior cruciate ligament ( ACL ) injury rate ( RR 0.12 , 95 % CI 0.01 to 0.85 ) , whereas the rate in the control group players was not significantly different from those in the low-compliance tertile ( RR 0.77 , 95 % CI 0.27 to 2.21 ) . A significant deterioration occurred in team ( b=−3.0 % per month , 95 % CI −5.2 to −0.8 ) and player ( b=−5.0 % per month , 95 % CI −7.1 to −2.9 ) compliance over the season . Conclusions Players with high compliance with the  NMT programme had significantly reduced ACL injury rate compared with players with low compliance . Significant deterioration in team and player compliance occurred over the season Background This study was conducted to investigate whether the most common injuries in soccer could be prevented , and to determine if a simple question naire could identify players at increased risk . Hypothesis Introduction of targeted exercise programs to male soccer players with a history of previous injury or reduced function in the ankle , knee , hamstring , or groin will prevent injuries . Study Design R and omized controlled trial ; Level of evidence , 2 . Methods A total of 508 players representing 31 teams were included in the study . A question naire indicating previous injury and /or reduced function as inclusion criteria was used to divide the players into high-risk ( HR ) ( 76 % ) and low-risk ( LR ) groups . The HR players were r and omized individually into an HR intervention group or HR control group . Results A total of 505 injuries were reported , sustained by 56 % of the players . The total injury incidence was a mean of 3.2 ( 95 % confidence interval [ CI ] , 2.5–3.9 ) in the LR control group , 5.3 ( 95 % Cl , 4.6–6.0 ) in the HR control group ( P = .0001 vs the LR control group ) , and 4.9 ( 95 % Cl , 4.3–5.6 ) in the HR intervention group ( P = .50 vs the HR control group ) . For the main outcome measure , the sum of injuries to the ankle , knee , hamstring , and groin , there was also a significantly lower injury risk in the LR control group compared with the 2 other groups , but no difference between the HR intervention group and the HR control group . Compliance with the training programs in the HR intervention group was poor , with only 27.5 % in the ankle group , 29.2 % in the knee group , 21.1 % in the hamstring group , and 19.4 % in the groin defined as having carried out the minimum recommended training volume . Conclusion The players with a significantly increased risk of injury were able to be identified through the use of a question naire , but player compliance with the training programs prescribed was low and any effect of the intervention on injury risk could not be detected 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 Background The injury risk in football is high , but little is known about causes of injury . Purpose To identify risk factors for football injuries using a multivariate model . Study Design Prospect i ve cohort study . Methods Participants were 306 male football players from the two highest divisions in Icel and . Before the 1999 football season started , the following factors were examined : height , weight , body composition , flexibility , leg extension power , jump height , peak O2 uptake , joint stability , and history of previous injury . Injuries and player exposure were recorded throughout the competitive season . Results Older players were at higher risk of injury in general ( odds ratio [ OR ] = 1.1 per year , P = 0.05 ) . For hamstring strains , the significant risk factors were age ( OR = 1.4 [ 1 year ] , P < 0.001 ) and previous hamstring strains ( OR = 11.6 , P < 0.001 ) . For groin strains , the predictor risk factors were previous groin strains ( OR = 7.3 , P = 0.001 ) and decreased range of motion in hip abduction ( OR = 0.9 [ 1 ° ] , P = 0.05 ) . Previous injury was also identified as a risk factor for knee ( OR = 4.6 ) and ankle sprains ( OR = 5.3 ) . Conclusions Age and previous injury were identified as the main risk factors for injury among elite football players from Icel and This prospect i ve study was conducted to determine whether hip muscle strength and flexibility play a role in the incidence of adductor and hip flexor strains in National Hockey League ice hockey team players .  Hip flexion , abduction , and adduction strength were measured in 81 players before two consecutive seasons . Thirty-four players were cut , traded , or sent to the minor league before the beginning of the season . Injury and individual exposure data were recorded for the remaining 47 players . Eight players experienced 11 adductor muscle strains , and there were 4 hip flexor strains . Preseason hip adduction strength was 18 % lower in the players who subsequently sustained an adductor muscle strain compared with that of uninjured players . Adduction strength was 95 % of abduction strength in the uninjured players but only 78 % of abduction strength in the injured players . Preseason hip adductor flexibility was not different between players who sustained adductor muscle strains and those who did not . These results indicate that preseason hip strength testing of professional ice hockey players can identify players at risk of developing adductor muscle strains . A player was 17 times more likely to sustain an adductor muscle strain if his adductor strength was less than 80 % of his abductor strength OBJECTIVE To investigate gender differences in three-dimensional hip and knee joint mechanics in collegiate athletes during a r and omly cued cutting maneuver . DESIGN Three-dimensional kinematics and kinetics were collected on 24 collegiate soccer players ( 12 females and 12 males ) while each performed the cutting maneuver .  In order to create a r and omly cued condition , subjects were signaled by a lighted target board that directed them to perform one of three tasks . Hip and knee joint mechanics were compared between genders using one-tailed t-tests . BACKGROUND Female athletes have an anterior cruciate ligament injury rate that is larger than their male counterparts . Gender differences in hip and knee joint mechanics during a r and omly cued cutting maneuver have not been previously reported . METHODS Five r and omly cued cutting trials were included in the analysis . Selected peak hip and knee joint angles and moments were measured during the first 40 degrees of knee flexion across the stance phase . RESULTS Females demonstrated significantly less peak hip abduction than did males . Otherwise , there were no gender differences in selected peak hip and knee joint kinematics and moments . CONCLUSIONS Male and female collegiate soccer players demonstrate similar hip and knee joint mechanics while performing a r and omly cued cutting maneuver . RELEVANCE Because it is known that females incur a greater number of anterior cruciate ligament injuries than males , it is of interest to identify gender differences in lower extremity mechanics when performing sport specific tasks . Underst and ing of these differences will contribute to the development of prevention training programs 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 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 
    Output:
    
Meta- analysis revealed a potential clinical ly meaningful groin injury reduction of 19 % , even though no statistical significant reduction in sport-related groin injuries could be documented .