***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 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 The purpose of this study was to determine the effect of a 4-week balance training program on specified functional tasks . Thirty-six subjects ( age = 22.7 ± 2.10 years ; height = 168.30 ± 9.55 cm ; weight = 71.15 ± 16.40 kg ) were r and omly placed into control ( C ; n = 19 ) and experimental groups ( Tx ; n = 17 ) . The Tx group trained using a commercially available balance training device ( BOSU ) . Postural limits ( displacement and sway ) and functional task ( time on ball , shuttle run , and vertical jump ) were assessed during a pretest ( T1 ) , a posttest ( T2 ) , and 2 weeks posttraining ( T3 ) . Multivariate repeated measures analysis ( a = 0.05 ) revealed significant differences in time on ball , shuttle run , total sway , and fore/aft displacement after the exercise intervention ( T2 ) . T3 assessment revealed that total sway and time on ball remained controlled ; however , no other measures were retained . Balance training improved performance of selected sport-related activities and postural control measures , although it is unclear whether the effect of training would transfer to general functional enhancement Balancing exercises on instable bases ( sensorimotor training [ SMT ] ) are often used in the rehabilitation process of an injured athlete to restore joint function . Recently it was shown that SMT was able to enhance rate of force development ( RFD ) in a maximal voluntary muscle contraction . The purpose of this study was to compare adaptations on strength capacity following ballistic strength training ( BST ) with those following an SMT during a training period of 1 microcycle ( 4 weeks ) . Maximum voluntary isometric strength ( MVC ) , maximum RFD ( RFDmax ) and the corresponding neural activation of M. soleus ( SOL ) , M. gastrocnemius ( GAS ) , and M. tibialis anterior ( TIB ) were measured during plantar flexion in 33 healthy subjects . The subjects were r and omly assigned to a SMT , BST , or control group . RFDmax increased significantly stronger following BST ( 48 ± 16 % ; p < 0.01 ) compared to SMT ( 14 ± 5 % ; p < 0.05 ) , whereas MVC remained unchanged in both groups . Median frequencies of the electromyographic power spectrum during the first 200 ms of contraction for GAS increased following both BST ( 45 ± 21 % ; p < 0.05 ) and SMT ( 45 ± 22 % ; p < 0.05 ) , but median frequencies for SOL increased only after SMT ( 13 ± 4 % ; p < 0.05 ) . Additionally , mean amplitude voltage increased following BST for SOL ( 38 ± 12 % ; p < 0.01 ) and for GAS ( 73 ± 23 % ; p < 0.01 ) during the first 100 ms , whereas it remained unchanged after SMT . It is concluded that BST and SMT may induce different neural adaptations that specifically affect recruitment and discharge rates of motor units at the beginning of voluntary contraction . Specific neural adaptations indicate that SMT might be used complementarily to BST , especially in sports that require contractile explosive properties in situations with high postural dem and s , e.g. , during jumps in ball sports Background : A number of studies have shown that proprioception training can reduce the risk of injuries in pivoting sports , but the mechanism is not clearly understood . Aim : To determine the contributing effects of propioception on knee joint position sense among team h and ball players . Study design : Prospect i ve cohort study . Methods : Two professional female h and ball teams were followed prospect ively for the 2005–6 season . 20 players in the intervention team followed a prescribed proprioceptive training programme while 19 players in the control team did not have a specific propioceptive training programme . The coaches recorded all exposures of the individual players . The location and nature of injuries were recorded . Joint position sense ( JPS ) was measured by a goniometer on both knees in three angle intervals , testing each angle five times . Assessment s were performed before and after the season by the same examiner for both teams . In the intervention team a third assessment was also performed during the season . Complete data were obtained for 15 subjects in the intervention team and 16 in the control team . Absolute error score , error of variation score and SEM were calculated and the results of the intervention and control teams were compared . Results : The proprioception sensory function of the players in the intervention team was significantly improved between the assessment s made at the start and the end of the season ( mean ( SD ) absolute error 9.78–8.21 ° ( 7.19–6.08 ° ) vs 3.61–4.04 ° (3.71–3.20 ° ) , p<0.05 ) . No improvement was seen in the sensory function in the control team between the start and the end of the season ( mean ( SD ) absolute error 6.31–6.22 ° (6.12–3.59 ° ) vs 6.13–6.69 ° (7.46–6.49 ° ) , p>0.05 ) . Conclusion : This is the first study to show that proprioception training improves the joint position sense in elite female h and ball players . This may explain the effect of neuromuscular training in reducing the injury rate The purpose of the present study was to investigate the effects of a soccer training session on the balance ability of the players and assess whether the effectiveness of a balance program is affected by its performance before or after the regular soccer training . Thirty-nine soccer players were r and omly divided into three subject groups ( n=13 each ) , one control group ( C group ) , one training group that followed a balance program ( 12 weeks , 3 times per week , 20 min per session ) before the regular soccer training ( TxB group ) , and one training group that performed the same balance program after the soccer training ( TxA group ) . St and ard testing balance boards and the Biodex Stability System were used to assess balance ability in the C , TxB , and TxA groups at baseline ( T0 ) and after completing the balance program ( T12 ) . The same tests and additional isokinetic knee joint moment measurements were carried out in the TxB and TxA groups pre- and post-soccer training . Two main results were obtained : ( 1 ) No differences ( p>0.05 ) were found in balance ability and knee joint moment production between pre- and post-soccer training . ( 2 ) The balance program increased ( p<0.01 ) the balance ability in the TxB and TxA groups , and the improvement in the TxA group was greater ( p<0.05 ) than that in the TxB group post-soccer training . Result ( 1 ) is in contrast to the notion of a link between fatigue induced by a soccer training session or game and injury caused by impaired balance , and result ( 2 ) has implication s for athletic training and rehabilitation The isolated effect of balance training on muscle strength of the flexors and extensors of the knee , without accompanying strength training , has not been addressed in the past . Effects of a balance training program alone were compared to a strength training program . Balance and strength training were performed by 15 persons each for 6 weeks including 12 training units of 25 min . Balance training was performed on instability training devices such as rolling board , mini trampoline and large rubber ball . The 15 persons of the strength training group  trained on machines for leg curls and on leg presses for 25 min per unit . Measurements for balance were performed with one-leg balance on a narrow edge and a tilting stabilometer for 30 s ; maximum isometric strength was measured using an isokinetic device for each leg separately . The muscular balance between dominant and non-dominant leg was calculated . Strength gain was similar for the flexors and extensors in both groups . One-leg balance improved after balance training ( P < 0.01 ) with a 100 % increase over the strength training group ( P < 0.05 ) and the stabilometer test for each person in the balance ( P < 0.01 ) , but not in the strength training group . In the balance group the initial difference between right and left diminished . The results indicate balance training to be effective for gain in muscular strength , and secondly , in contrast to strength training , equalisation of muscular imbalances may be achieved after balance training Total sagittal knee laxity and postural control in the sagittal and frontal planes were measured in 25 patients at a mean of 36 months ( range , 27 to 44 ) after anterior cruciate ligament reconstruction and in a control group consisting of 20 uninjured age- and activity-matched subjects .  Body sway was measured in the sagittal plane on a stable and on a sway-referenced force plate in single-legged stance , double-legged stance , or both , with the eyes open and closed . Postural reactions to perturbations in the sagittal and frontal planes were recorded in the single-legged stance with the eyes open . Total sagittal plane laxity was significantly greater in the anterior cruciate ligament-reconstructed knee ( 11.2 mm ; range , 6 to 15 ) than in the uninjured knee ( 8.9 mm ; range , 6 to 12 ) or in the control group ( 6.0 mm ; range , 5 to 8) . In spite of this , the patients , in comparison with the controls , exhibited normal postural control except in two variables — the reaction time and the latency between the start of force movement to maximal sway in the sagittal plane perturbations . This supports the hypothesis that rehabilitation , with proprioceptive and agility training , is an important component in restoring the functional stability in the anterior cruciate ligament-reconstructed knee Background Ankle sprains are the most common musculoskeletal injuries that occur in athletes , and they have a profound impact on health care costs and re sources . Hypothesis A balance training program can reduce the risk of ankle sprains in high school athletes . Study Design R and omized controlled clinical trial ; Level of evidence , 1 . Methods Seven hundred and sixty-five high school soccer and basketball players ( 523 girls and 242 boys ) were r and omly assigned to either an intervention group ( 27 teams , 373 subjects ) that participated in a balance training program or to a control group ( 28 teams , 392 subjects ) that performed only st and ard conditioning exercises . On-site athletic trainers recorded athlete exposures and sprains . Results The rate of ankle sprains was significantly lower for subjects in the intervention group ( 6.1 % , 1.13 of 1000 exposures vs 9.9 % , 1.87 of 1000 exposures ; P = . 
    Output:
    
Balance training was effective in improving postural sway and functional balance when compared with untrained control participants .
Larger effect sizes were shown for training programs of longer duration .
Although controversial findings were reported for jumping performance , agility , and neuromuscular control , there are indications for the effectiveness of balance training in these outcomes .
When compared with plyometric or strength training , conflicting results or no effects of balance training were reported for strength improvements and changes in sprint performance .
CONCLUSIONS We conclude that balance training can be effective for postural and neuromuscular control improvements .