***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 Ankle injuries account for 30 to 60 % of all parachuting injuries . This study was design ed to determine if outside-the-boot ankle braces could reduce ankle sprains during Army paratrooper training . METHODS The r and omized trial involved 777 volunteers from the U.S. Army Airborne School , Fort Benning , Ga. Of this group , 745 completed all study requirements ( 369 brace-wearers and 376 non-brace-wearers ) . Each volunteer made five parachute jumps , for a total of 3,674 jumps . RESULTS The incidence of inversion ankle sprains was 1.9 % in non-brace-wearers and 0.3 % in brace-wearers ( risk ratio , 6.9 ; p = 0.04 ) . Other injuries appeared unaffected by the brace . Overall , 5.3 % of the non-brace group and 4.6 % of the brace group experienced at least one injury . The risk ratio for injured individuals was 1.2:1 ( non-brace to brace groups ; p = 0.65 ) . CONCLUSION Inversion ankle sprains during parachute training can be significantly reduced by using an outside-the-boot ankle brace , with no increase in risk for other injuries To study the efficacy of an injury prevention program in a r and omized trial , 12 teams ( 180 players ) in a male senior soccer division were followed up for 6 months . The 12 teams were allocated at r and om to two groups of six teams , one being given a prophylactic program and the other serving as control . The program was based on previous studies of injury mechanisms . It comprised ( 1 ) correction of training , ( 2 ) provision of optimum equipment ; ( 3 ) prophylactic ankle taping ; ( 4 ) controlled rehabilitation ; ( 5 ) exclusion of players with grave knee instability ; ( 6 ) information about the impor tance of disciplined play and the increased risk of injury at training camps ; and ( 7 ) correction and supervision by doctor(s ) and physiotherapist(s ) . The injuries in the test teams were 75 % fewer than in the controls . The most common types of soccer injuries , sprains and strains to ankles and knees , were all significantly reduced . It is concluded that the pro posed prophylactic program , including close supervi sion and correction by doctors and physiotherapists , significantly reduces soccer injuries Ankle supports are commonly used in an attempt to decrease the risk of ankle injury during sport . However , their use may also impair postural control , which is an integral component of sports participation . The aim of this study was to investigate the effects of three different ankle supports ( tape , brace , and elastic b and age ) on postural control in 24 normal subjects with a mean age of 24.8 years ( + /- 4.4 ) . Two measures were used to evaluate postural control in one-legged stance with the eyes closed : variability of mediolateral ground reaction force ( acquired from a force platform ) and frequency of foot touchdowns by the nonsupport leg ( assumed to indicate ability of the subject to maintain one-legged stance posture ) . Both measures revealed a differential effect for ankle support on postural control . The use of an elastic b and age had no significant effect on postural control ( p > 0.05 ) , while the use of tape or a brace had a significant detrimental effect ( p < 0.05 ) . While wearing the tape or a brace , subjects were less steady and touched down more frequently . Restriction of ankle movement was offered as a possible explanation for the results , since postural control was impaired only by the ankle supports which limited ankle motion . These findings may have implication s regarding impaired athletic performance 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 A study was undertaken to evaluate the effect of a semi rigid ankle orthosis ( Sport-Stirrup ) on the incidence of ankle sprains  in soccer players during 1 playing season . Senior soccer players were divided into 2 groups : play ers with previous ankle sprains ( N = 258 ) and players without such history ( N = 246 ) . The players in these groups were each r and omly allocated to either a semi rigid orthosis or a control group at the start of the playing season . All subsequent injuries during the season and the total number of playing hours were documented . There was a significant reduction in the incidence of ankle sprains ( injuries/1 000 playing hours ) by ankles in the orthosis group with previous sprains ( 0.14 ) com pared with the nonbraced group with previous sprains ( 0.86 ) . The incidence of ankle sprains was significantly higher in the nonbraced group with previous sprains ( 0.86 ) compared with the nonbraced group without pre vious sprains ( 0.46 ) . Thus , in this study , a semirigid or thosis significantly reduced the incidence of recurrent ankle sprains in soccer players with previous history of ankle sprains The purpose of this study was to examine a young athletic population to up date the data regarding epidemiology and disability associated with ankle injuries . At the United States Military Academy , all cadets presenting with ankle injuries during a 2-month period were included in this prospect i ve observational study . The initial evaluation included an extensive question naire , physical examination , and radiographs . Ankle sprain treatment included a supervised rehabilitation program . Subjects were reevaluated at 6 weeks and 6 months with subjective  assessment , physical  examination  , and functional testing . The mean age for all subjects was 20 years ( range , 17–24 years ) . There were 104 ankle injuries accounting for 23 % of all injuries seen . There were 96 sprains , 7 fractures , and 1 contusion . Of the 96 sprains , 4 were predominately medial injuries , 76 were lateral , and 16 were syndesmosis sprains . Ninety-five percent had returned to sports activities by 6 weeks ; however , 55 % of these subjects reported loss of function or presence of intermittent pain , and 23 % had a decrement of > 20 % in the lateral hop test when compared with the uninjured side . At 6 months , all subjects had returned to full activity ; however , 40 % reported residual symptoms and 2.5 % had a decrement of > 20 % on the lateral hop test . Neither previous injury nor ligament laxity was predictive of chronic symptomatology . Furthermore , chronic dysfunction could not be predicted by the grade of sprain ( grade I vs. II ) . The factor most predictive of residual symptoms was a syndesmosis sprain , regardless of grade . Syndesmosis sprains were most prevalent in collision sports . This study demonstrates that even though our knowledge and underst and ing of ankle sprains and rehabilitation of these injuries have progressed in the last 20 years , chronic ankle dysfunction continues to be a prevalent problem . The early return to sports occurs after almost every ankle sprain ; however , dysfunction persists in 40 % of patients for as long as 6 months after injury . Syndesmosis sprains are more common than previously thought , and this confirms that syndesmosis sprains are associated with prolonged disability The aim of this study was to investigate whether the number of patients with residual symptoms following ankle sprains could be reduced by training on a wobble board during a 12-week training recovery period . The effect of a 12-week training program was compared to no training .  Forty-eight patients completed the study . In the follow-up period ( mean 230 days ) we found significantly fewer recurrent distorsions and fewer patients had functional instability in the study group compared to controls . There were no differences between the two groups concerning subjective complaints during the recovery period . Volumetric measurements revealed no difference in the speed of reduction of haematoma and oedema in the two groups . We conclude that training on a wobble board is effective in reducing residual symptoms following ankle sprains We evaluated the effect of different ankle support de vices on  athletic performance .  Thirty varsity college athletes were tested with both ankles supported by taping , Swede-O brace , Kallassy brace or left unsup ported . The athletes performed four events : broad jump , vertical leap , 10 yard shuttle run , and 40 yard sprint . The events and appliances were r and omized to prevent bias by fatigue . Compared to the results when no support was used , ankle taping result ed in a significant decreased perform ance in the vertical jump ( 4 % ) , shuttle run ( 1.6 % ) , and sprint ( 3.5 % ) ( P < 0.05 ) . Use of the Swede-O brace decreased performance in the vertical jump ( 4.6 % ) , broad jump ( 3.6 % ) , and time of the sprint ( 3.2 % ) . Re sults using the Kallassy brace showed a decrease in the vertical jump ( 3.4 % ) when compared to no support . The test results of the shuttle run with taping were slower than the Kallassy brace ( P < 0.05 ) . Wearing the Swede-O brace caused the athletes ' broad jump dis tance to decrease more than the Kallassy brace ( P < 0.05 ) . Subjective question naires supported the Kallassy brace as the most comfortable support and the one that decreased performance the least . Taping of the ankles is universally accepted for ankle prophylaxis . This study has shown a decrease in per formance when ankles are taped compared to ankles with no protection . Since the decreases in performance caused by ankle braces are minor , this should not be used as a criterion for selection of prophylactic support compared to taping This study investigated the relationship between exposure time and ankle sprains in soccer . Forty-one teams ( 639 players ) from four male senior soccer divisions at different levels of skill ( divisions I-VI ) were followed prospect ively for 1 year . The exposure to soccer  and the number of injuries per player were higher in higher divisions , but the injury incidence , percentage of ankle injuries and incidence of ankle injuries were the same at different levels of skill . Of all injuries 17 to 20 % were ankle sprains and the incidence varied between 1.7 to 2.0 ankle injuries per 1000 hours of exposure . Since players with previous ankle problems run an increased risk of reinjury we suggest that these players receive preventive advice Ankle sprains are often complicated by functional instability and repeated sprains . Rehabilitation with wobble boards in patients with functional instability has been tested , and significant improvement has been found compared to no training . The aim of this study was to investigate whether the number of patients with residual symptoms following ankle sprains could be reduced by training on a wobble board during 12-week recovery period . In addition , the influence of training in the time course reduction of edema was investigated . We performed a prospect i ve study including 61 patients , all active in sports for more than 2 hours a week with primary ankle sprains . The effect of a 12-week training program with wobble board was compared with no training .  Forty-eight patients completed the study . In the follow-up period ( mean X = 230 days ) , we found significantly fewer recurrent sprains , and significantly fewer patients in the training group had functional instability of the ankle compared with the no training group . There were no differences in the two groups in the time which elapsed before patients were painless at walking , during running , or at sports . Volumetric measurements revealed no difference in the speed of reduction of hematoma and edema of the ankle and foot between the two groups . We conclude that training on a wobble board early after primary stage 2 ankle sprains is effective in reducing residual symptoms following this lesion and that training does not seem to affect the time course reduction in edema This r and omized clinical study was design ed to pro spectively determine the efficacy of a semirigid ankle stabilizer in reducing the frequency and severity of acute ankle injuries in basketball . Athletic shoe , playing surface , athlete-exposure , ankle injury history , and brace assignment were either statistically or experimen tally controlled . Participants in the study were 1601 United States Military Academy cadets with no prepar ticipation , clinical , functional , or radiographic evidence of ankle instability . Subjects experienced a total of 13,430 athlete-exposures in the 199 
    Output:
    
There was no apparent difference in the severity of ankle sprains or any change to the incidence of other leg injuries .
The protective effect of ' high-top ' shoes remains to be established .
There was limited evidence for reduction in ankle sprain for those with previous ankle sprains who did ankle disk training exercises .
REVIEW ER 'S CONCLUSIONS This review provides good evidence for the beneficial effect of ankle supports in the form of semi-rigid orthoses or air-cast braces to prevent ankle sprains during high-risk sporting activities ( e.g. soccer , basketball ) .
Participants with a history of previous sprain can be advised that wearing such supports may reduce the risk of incurring a future sprain .