***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: To which groups of patients can the results of clinical trials be applied ? This question is often inappropriately answered by reference to the trial entry criteria . Instead , the benefit and harm ( adverse events , discomfort of treatment , etc ) of treatment could be assessed separately for individual patients . Patients at greatest risk of a disease will have the greatest net benefit as benefit to patients usually increases with risk while harm remains comparatively fixed . To assess net benefit , the relative risks should come from ( a meta- analysis of ) r and omised trials ; the risk in individual patients should come from multivariate risk equations derived from cohort studies . However , before making firm conclusions , the assumptions of fixed adverse effects and constant reduction in relative risk need to be checked Abstract The effects of an 8-week unilateral contract-relax ( CR ) stretching training program ( passive stretch after isometric contraction ) on muscular performance were investigated in a group of 16 athletes . The flexibility , maximum torque and angular position as well as contraction work in movements of the knee joint were determined before training and after 4 and 8 weeks of training . The torque measurements were performed under isokinetic conditions , eccentrically at angular velocities of 60 ° · s−1 and 120 ° · s−1 , isometrically at five different joint positions , and concentrically at angular velocities of 60 , 120 , 180 and 240 ° · s−1 using an isokinetic dynamometer . A surface electromyogram ( EMG ) of the thigh muscles ( quadriceps and hamstrings ) was recorded simultaneously . As compared to untrained control limbs , significant improvements in active and passive flexibility ( up to 6.3 ° in range of motion ) , maximum torque ( up to 21.6 % ) and work ( up to 12.9 % ) were observed , and these were especially pronounced under eccentric load conditions . A comparison between integrated EMG recordings during eccentric and concentric loads , as well as the interpretation of the training-induced changes in the EMG , suggest that muscular activity under eccentric loads may be impaired by mental processes Eccentric activities are an important component of physical conditioning and everyday activities .  Delayed onset muscle soreness ( DOMS )  can result from strenuous eccentric tasks and can be a limiting factor in motor performance for several days after exercise . An efficacious method of treatment for DOMS would enhance athletic performance and hasten the return to activities of daily living . The purpose of this study was to identify a treatment method which could assist in the recovery of DOMS . In the selection of treatment methods , emphasis was directed toward treatments that could be rendered independently by an individual , therefore making the treatment valuable to an athletic trainer in team setting . DOMS was induced in 70 untrained volunteers via 15 sets of 15 eccentric contractions of the forearm extensor muscles on a Lido isokinetic dynamometer . All subjects performed a pilot exercise bout for a minimum of 9 weeks before data collection to assure that DOMS would be produced . Data were collected on 15 dependent variables : active and passive wrist flexion and extension , forearm girth , limb volume , visual analogue pain scale , muscle soreness index , isometric strength , concentric and eccentric wrist total work , concentric and eccentric angle of peak torque . Data were collected on six occasions : pre- and post-induced DOMS , 20 minutes after treatment , and 24 , 48 , and 72 hours after treatment . Subjects were r and omly assigned to 1 of 7 groups ( 6 treatment and 1 control ) . Treatments included a nonsteroidal anti-inflammatory drug , high velocity concentric muscle contractions on an upper extremity ergometer , ice massage , 10-minute static stretching , topical Amica montana ointment , and sublingual A. montana pellets . A 7 x 6 ANOVA with repeated measures on time was performed on the delta values of each of the 15 dependent variables . Significant main effects ( p < .05 ) were found for all of the dependent variables on time only . There were no significant differences between treatments . Therefore , we conclude that none of the treatments were effective in abating the signs and symptoms of DOMS . In fact , the NSAID and A. montana treatments appeared to impede recovery of muscle function Most systematic review s rely substantially on the assessment of the method ological quality of the individual trials . The aim of this study was to obtain consensus among experts about a set of generic core items for quality assessment of r and omized clinical trials ( RCTs ) . The invited participants were experts in the field of quality assessment of RCTs . The initial item pool contained all items from existing criteria lists . Subsequently , we reduced the number of items by using the Delphi consensus technique . Each Delphi round comprised a question naire , an analysis , and a feedback report . The feedback report included staff team decisions made on the basis of the analysis and their justification . A total of 33 international experts agreed to participate , of whom 21 completed all question naires . The initial item pool of 206 items was reduced to 9 items in three Delphi rounds . The final criteria list ( the Delphi list ) was satisfactory to all participants . It is a starting point on the way to a minimum reference st and ard for RCTs on many different research topics . This list is not intended to replace , but rather to be used alongside , existing criteria lists The purpose of this intervention study was to prove that increasing flexibility of the hamstring musculotendinous unit would decrease the number of lower extremity overuse injuries that occur in military infantry basic trainees . Two different companies going through basic training at the same time were used . Hamstring flexibility was checked at the beginning and at the end of the 13-week infantry basic training course . The control company ( N 148 ) proceeded through normal basic training . The intervention company ( N 150 ) followed the same program but added three hamstring stretching sessions to their already scheduled fitness program . All subsequent lower extremity overuse injuries were recorded through the troop medical clinic . Hamstring flexibility increased significantly in the intervention group compared with the control group . The number of injuries was also significantly lower in the intervention group . Forty-three injuries occurred in the control group for an incidence rate of 29.1 % , compared with 25 injuries in the intervention group for an incidence rate of 16.7 % . Thus , in this study , the number of lower extremity overuse injuries was significantly lower in infantry basic trainees with increased hamstring flexibility This paper discusses statistical techniques for the analysis of dichotomous data arising from a design in which the investigator r and omly assigns each of two clusters of possibly varying size to interventions within strata . The problem addressed is that of assessing the statistical significance of the intervention effect over all strata . We propose a weighted  paired t-test  based on the empirical logistic transform for design s that r and omize large aggregate clusters in each of several strata The present study sought to investigate the effects of preexercise stretching on  delayed onset muscle soreness ( DOMS ) , i.e. soreness , tenderness and loss of muscle force , that usually occurs after strenuous or unaccustomed eccentric exercise . Ten female volunteers performed 10 sets of 10 maximal isokinetic eccentric contractions for knee flexion with both legs after a 5-min ergometer cycling warm-up . Prior to the exercise for one leg , r and omly chosen , 4 x 20 s of static stretching for the hamstring muscle group was implemented . Rated soreness , tenderness on algometer pressure and loss of maximal eccentric contractile force was evaluated preexercise and 24 , 48 and 96 h postexercise . The exercise bout produced severe DOMS , with parameters peaking and troughing at 48 h postexercise . However , no significant differences were found , regarding any of the parameters , when comparing stretched and nonstretched legs . The present study thus suggests that preexercise static stretching has no preventive effect on the muscular soreness , tenderness and force loss that follows heavy eccentric exercise Thirty-six male subjects aged 18 to 26 years were assigned at r and om to one of three treatment groups : biofeedback , static stretch , and control . Muscle soreness was produced in all subjects by an 80 % maximal eccentric contraction of the biceps brachii . The subjects in the biofeedback group applied auditory electromyographic ( EMG ) feedback at 6 , 25 , 30 , 49 , and 54 hours after the exercise , and the stretch group applied static stretch to the exercised arm at the same time periods . Observations of EMG activity and perceived pain level were made immediately before and after exercise , and at 24 , 48 , and 72 hours following exercise . When compared with a control group , both auditory biofeedback and static stretching significantly reduced EMG muscle activity but had no significant effect on perceived pain . The EMG activity and perceived pain of the subjects in each treatment group significantly differed across observations This study investigated effects of ankle dorsiflexion range and pre-exercise calf muscle stretching on relative risk of selected injuries in 1093 male Army recruits undertaking 12 weeks of intensive training . Prior to training , ankle dorsiflexion range was measured and recruits were allocated to stretch and control groups using a quasi-r and om procedure . The stretch group stretched calf muscles under supervision prior to all intense exercise . The control group stretched upper limb muscles instead . Forty-eight injuries were recorded . Survival analysis indicated that ankle dorsiflexion range was a strong predictor of injury ( p = 0.03 ) . Definitive evidence of an effect of stretching on injury risk was not found ( p = 0.76 ) , but the sample size may have been insufficient to detect such an effect It has been suggested in the lay literature that static stretching and /or warm-up will prevent the occurrence of  Delayed-Onset Muscle Soreness ( DOMS ) .  The primary purpose of this study was to determine the effects of static stretching and /or warm-up on the level of pain associated with DOMS . Sixty-two healthy male and female volunteers were r and omly assigned to four groups : ( a ) subjects who statically stretched the quadriceps muscle group before a step , ( b ) subjects who only performed a stepping warm-up , ( c ) subjects who both stretched and performed a stepping warm-up prior to a step test , and ( d ) subjects who only performed a step test . The step test ( Asmussen , 1956 ) required subjects to do concentric work with their right leg and eccentric work with their left leg to voluntary exhaustion . Subjects rated their muscle soreness on a ratio scale from zero to six at 24-hour intervals for 5 days following the step test . A 4x2x2 ANOVA with repeated measures on legs and Duncan 's New Multiple Range post-hoc test found no difference in peak muscle soreness among the groups doing the step test or for gender ( p greater than .05 ) . There was the expected significant difference in peak muscle soreness between eccentrically and concentrically worked legs , with the eccentrically worked leg experiencing greater muscle soreness . We concluded that static stretching and /or warm-up does not prevent DOMS result ing from exhaustive exercise PURPOSE This study investigated the effect of muscle stretching during warm-up on the risk of exercise-related injury . METHODS 1538 male army recruits were r and omly allocated to stretch or control groups . During the ensuing 12 wk of training , both groups performed active warm-up exercises before physical training sessions . In addition , the stretch group performed one 20-s static stretch under supervision for each of six major leg muscle groups during every warm-up . The control group did not stretch . RESULTS 333 lower-limb injuries  were recorded during the training period , including 214 soft-tissue injuries . There were 158 injuries in the stretch group and 175 in the control group . There was no significant effect of preexercise stretching on all-injuries risk ( hazard ratio [ HR ] = 0.95 , 95 % CI 0.77 - 1.18 ) , soft-tissue injury risk ( HR = 0.83 , 95 % CI 0.63 - 1.09 ) , or bone injury risk ( HR = 1.22 , 95 % CI 0.86 - 1.76 ) . Fitness ( 20-m progressive shuttle run test score ) , age , and enlistment date all significantly predicted injury risk ( P < 0.01 for each ) , but height , weight , and body mass index did not . CONCLUSION A typical muscle stretching protocol performed during preexercise warm-ups does not produce clinical ly meaningful reductions in risk of exercise-related injury  in army recruits . Fitness may be an important , modifiable risk factor 
    Output:
    
Stretching produced small and statistically non-significant reductions in muscle soreness .
Stretching before or after exercising does not confer protection from muscle soreness .
Insufficient research has been done with which to determine the effects of stretching on sporting performance