***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: It has been shown in classical strength training studies using high loads that improvements in rate of force development are mainly due to adaptations in the intramuscular coordination . Adaptations following sensorimotor training were also characterized by improvements in the rate of force development during maximum voluntary isometric contraction . The purpose of the present study was to investigate neuromuscular adaptations of combined sensorimotor and classical strength training .  Eighteen subjects were r and omly assigned to two groups . Group 1 ( SMT-HST ) had to perform a period of sensorimotor training at first and a high-intensity strength training afterwards . Group 2 ( HST-SMT ) performed the high intensity strength training at first and the sensorimotor training after .  Maximum voluntary isometric contraction and neuromuscular activation were measured at three occasions : Before training , after the first , and after the second period . The results after the first period confirmed the positive effects of both training regimen on rate of force development ( 13 % [ SMT-HST ] and 27 % [ HST-SMT ] , p < 0.05 ) and on maximum strength ( 9 % [ HST-SMT ] and 12 % [ SMT-HST ] , p < 0.05 ) during maximum voluntary contraction . Improvements caused by sensorimotor training could only be achieved , when it was performed at first . It is supposed that classical strength training with high loads basically improves the mechanical efficiency of the effectors , whereas sensorimotor training alters the afferent input on the central nervous system . In combination , the sensorimotor training can have preconditioning effects on the strength training . A combination of both training methods can thus be recommended , if the sensorimotor training is performed at first STUDY DESIGN R and omized controlled trial with repeated measures . OBJECTIVES To determine the effect of trunk stability training on  vertical takeoff velocity .  BACKGROUND Trunk stability training is commonly used in sports training programs ; however , the effects of stability training on performance enhancement are not known . Trunk stability training may provide a more stable pelvis and spine from which the leg muscles can generate action , may better link the upper body to the lower body , or may enhance leg muscle activation , thus promoting optimal force production during sporting activities such as a vertical jump . METHODS AND MEASURES Fifty-five athletes were r and omly assigned to 1 of 4 training groups :  trunk stability ( TS ) , leg strength ( LS ) , trunk stability and leg strength ( TL ) , and control ( CO ) . Subjects were tested 3 times : at pretraining , after 3 weeks of training , and after 9 weeks of training . A repeated- measures analysis of covariance ( ANCOVA ) was used to examine differences among groups for vertical takeoff velocity measured indirectly using a force plate . Pretraining takeoff velocity and body mass were used as covariates . RESULTS After 3 and 9 weeks , the training groups were not different from each other . After 9 weeks of training , all 3 training groups had a greater takeoff velocity than the control group ( P<.05 ) . After 3 weeks of training only the TS group had a greater takeoff velocity than the control group ( P<.05 ) . Only the TL group increased significantly in vertical takeoff velocity between the third- and ninth-week testing periods ( P<.05 ) . CONCLUSIONS Nine weeks of trunk stability training was similarly effective in enhancing vertical takeoff velocity as leg strength training or the combination of trunk stability and leg strength training Saeterbakken , AH , van den Tillaar , R , and Seiler , S. Effect of core stability training on throwing velocity in female h and ball players . J Strength Cond Res 25(3 ) : 712 - 718 , 2011-The purpose was to study the effect of a sling exercise training (SET)-based core stability program on maximal throwing velocity among female h and ball players . Twenty-four female high-school h and ball players ( 16.6 ± 0.3 years , 63 ± 6 kg , and 169 ± 7 cm ) participated and were initially divided into a SET training group ( n = 14 ) and a control group ( CON , n = 10 ) . Both groups performed their regular h and ball training for 6 weeks . In addition , twice a week , the SET group performed a progressive core stability-training program consisting of 6 unstable closed kinetic chain exercises . Maximal throwing velocity was measured before and after the training period using photocells . Maximal throwing velocity significantly increased 4.9 % from 17.9 ± 0.5 to 18.8 ± 0.4 m·s−1 in the SET group after the training period ( p < 0.01 ) , but was unchanged in the control group ( 17.1 ± 0.4 vs. 16.9 ± 0.4 m·s−1 ) . These results suggest that core stability training using unstable , closed kinetic chain movements can significantly improve maximal throwing velocity . A stronger and more stable lumbopelvic-hip complex may contribute to higher rotational velocity in multisegmental movements . Strength coaches can incorporate exercises exposing the joints for destabilization force during training in closed kinetic chain exercises . This may encourage an effective neuromuscular pattern and increase force production and can improve a highly specific performance task such as throwing PURPOSE To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming . METHODS Twenty national-level junior swimmers ( 10 male and 10 female , 16±1 y , 171±5 cm , 63±4 kg ) participated in the study . Group allocation ( intervention [ n=10 ] , control [ n=10 ] ) was based on  2 preexisting swim-training groups  who were part of the same swimming club but trained in different groups . The intervention group completed the core training , incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula , 3 times/wk for 12 wk . While the training was performed in addition to the normal pool-based swimming program , the control group maintained their usual pool-based swimming program . The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function . RESULTS Compared with the control group , the core-training intervention group had a possibly large beneficial effect on 50-m swim time ( -2.0 % ; 90 % confidence interval -3.8 to -0.2 % ) . Moreover , it showed small to moderate improvements on a timed prone-bridge test ( 9.0 % ; 2.1 - 16.4 % ) and asymmetric straight-arm pull-down test ( 23.1 % ; 13.7 - 33.4 % ) , and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction . CONCLUSION This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance BACKGROUND AND PURPOSE Assessment of the quality of r and omized controlled trials ( RCTs ) is common practice in systematic review s. However , the reliability of data obtained with most quality assessment scales has not been established . This report describes 2 studies design ed to investigate the reliability of data obtained with the Physiotherapy Evidence Data base ( PEDro ) scale developed to rate the quality of RCTs evaluating physical therapist interventions . METHOD In the first study , 11 raters independently rated 25 RCTs r and omly selected from the PEDro data base . In the second study , 2 raters rated 120 RCTs r and omly selected from the PEDro data base , and disagreements were resolved by a third rater ; this generated a set of individual rater and consensus ratings . The process was repeated by independent raters to create a second set of individual and consensus ratings . Reliability of ratings of PEDro scale items was calculated using multirater kappas , and reliability of the total ( summed ) score was calculated using intraclass correlation coefficients ( ICC [ 1,1 ] ) . RESULTS The kappa value for each of the 11 items ranged from.36 to.80 for individual assessors and from.50 to.79 for consensus ratings generated by groups of 2 or 3 raters . The ICC for the total score was.56 ( 95 % confidence interval=.47-.65 ) for ratings by individuals , and the ICC for consensus ratings was.68 ( 95 % confidence interval=.57-.76 ) . DISCUSSION AND CONCLUSION The reliability of ratings of PEDro scale items varied from " fair " to " substantial , " and the reliability of the total PEDro score was " fair " to " good . STUDY DESIGN Correlation study OBJECTIVES To objective ly evaluate the relationship between  core stability  and athletic performance measures in male and female collegiate athletes . BACKGROUND The relationship between core stability and athletic performance has yet to be quantified in the available literature . The current literature does not demonstrate whether or not core strength relates to functional performance . Questions remain regarding the most important components of core stability , the role of sport specificity , and the measurement of core stability in relation to athletic performance . METHODS A sample of 35 volunteer student athletes from Asbury College ( NAIA Division II ) provided informed consent . Participants performed a series of five tests : double leg lowering ( core stability test ) , the forty yard dash , the T-test , vertical jump , and a medicine ball throw . Participants performed three trials of each test in a r and omized order . RESULTS Correlations between the core stability test and each of the other four performance tests were determined using a General Linear Model . Medicine ball throw negatively correlated to the core stability test ( r -0.389 , p=0.023 ) . Participants that performed better on the core stability test had a stronger negative correlation to the medicine ball throw ( r = -0.527 ) . Gender was the most strongly correlated variable to core strength , males with a mean measurement of double leg lowering of 47.43 degrees compared to females having a mean of 54.75 degrees . CONCLUSIONS There appears to be a link between a  core stability test  and athletic performance tests ; however , more research is needed to provide a definitive answer on the nature of this relationship . Ideally , specific performance tests will be able to better define and to examine relationships to core stability . Future studies should also seek to determine if there are specific sub-categories of core stability which are most important to allow for optimal training and performance for individual sports & NA ; Ebben , W.P. , A.G. Kindler , K.A. Chirdon , N.C. Jenkins , A.J. Polichnowski , and A.V. Ng . The effect of high‐load vs. high‐repetition training on endurance performance . J. Strength Cond . Res . 18(3):513–517 . 2004.—The purpose of this study was to compare the effects of high‐load ( H‐load ) periodized resistance training and high‐repetition ( H‐rep ) reverse step loading periodized resistance training on endurance performance . Twenty‐six female university rowers ( age = 20 ± 1 year ) were r and omly assigned to H‐load ( 5 novice , 8 varsity ) or H‐rep ( 7 novice , 6 varsity ) groups . Subjects were pre‐ and posttested using a 2,000‐m rowing ergometer test . Outcome variables included SymbolO2 peak , time to test completion , total power , average power per stroke , total number of strokes , stroke rate , and body mass . Subjects trained for 8 weeks using identical exercises . Varsity rowers who performed H‐load training demonstrated greater improvement compared with those who performed H‐rep training . Novice rowers who performed H‐rep training demonstrated greater improvement compared with those who performed H‐load training . High‐load periodized training appears to be more effective for athletes with advanced training status , and H‐rep reverse step loading periodized training is more effective for those who are relatively untrained . Symbol . No caption available This study examined the effect of 12 weeks of medicine ball training on high school baseball players . Forty-nine baseball players ( age 15.4 ± 1.2 years ) were r and omly assigned using a stratified sampling technique to 1 of 2 groups . Group 1 ( n = 24 ) and group 2 ( n = 25 ) performed the same full-body resistance exercises according to a stepwise periodized model and took 100 bat swings a day , 3 days per week , with their normal game bat for 12 weeks . Group 2 performed additional rotational and full-body medicine ball exercises 3 days per week for 12 weeks . Pre- and post-testing consisted of a 3 repetition maximum ( RM ) dominant and nondominant torso rotational strength and sequential hip-torso-arm rotational strength ( medicine ball hitter 's throw ) . A 3RM parallel squat and bench press were measured at 0 and after 4 , 8 , and 12 weeks of training . Although both groups made statistically significant increases ( p > 0.05 ) in dominant ( 10.5 vs. 17.1 % ) and nondominant ( 10.2 vs. 18.3 % ) torso rotational strength and the medicine ball hitter 's throw ( 3.0 vs. 10.6 % ) , group 2 showed significantly greater increases in all 3 variables than group 1 . Furthermore , both groups made significant increases in predicted 1RM parallel squat and bench press after 4 , 8 , and 12 weeks of training ; however , there were no differences between groups . These data indicate that performing a 12-week medicine ball training program in addition to a stepwise periodized resistance training program with bat swings provided greater sport-specific training improvements in torso rotational and sequential hip-torso-arm rotational strength for high school baseball players Nesser , TW , Huxel , KC , Tincher , JL , and Okado , T. The relationship between core stability and performance in Division I football players . J Strength Cond Res 22(6):1750 - 1754 , 2008-The purpose of this study was to identify relationships between core stability and various strength and power variables in strength and power athletes . National Collegiate Athletic Association Division I football players ( height 184.0 
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Conclusions Our findings indicate that TMS plays only a minor role for physical fitness and athletic performance in trained individuals .
In fact , CST appears to be an effective means to  increase TMS and was associated with only limited gains in physical fitness and athletic performance measures when compared with no or only regular training