***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: Contractile force is transmitted to the skeleton through tendons and aponeuroses , and , although it is appreciated that the mechanocharacteristics of these tissues play an important role for movement performance with respect to energy storage , the association between tendon mechanical properties and the contractile muscle output during high-force movement tasks remains elusive . The purpose of the study was to investigate the relation between the mechanical properties of the connective tissue and muscle performance in maximal isometric and dynamic muscle actions . Sixteen trained men participated in the study . The mechanical properties of the vastus lateralis tendon-aponeurosis complex were assessed by ultrasonography .  Maximal isometric knee extensor force and rate of torque development ( RTD ) were determined . Dynamic performance was assessed by maximal squat jumps and countermovement jumps on a force plate . From the vertical ground reaction force , maximal jump height , jump power , and force-/velocity-related determinants of jump performance were obtained . RTD was positively related to the stiffness of the tendinous structures ( r = 0.55 , P < 0.05 ) , indicating that tendon mechanical properties may account for up to 30 % of the variance in RTD . A correlation was observed between stiffness and maximal jump height in squat jumps and countermovement jumps ( r = 0.64 , P < 0.05 and r = 0.55 , P < 0.05 ) . Power , force , and velocity parameters obtained during the jumps were significantly correlated to tendon stiffness . These data indicate that muscle output in high-force isometric and dynamic muscle actions is positively related to the stiffness of the tendinous structures , possibly by means of a more effective force transmission from the contractile elements to the bone The aim of this study was to measure if passive stretching would influence  delayed onset muscle soreness ( DOMS ) , dynamic muscle strength , plasma creatine kinase concentration ( CK ) and the ratio of phosphocreatine to inorganic phosphate ( PCr/P(i ) ) following eccentric exercise .  Seven healthy untrained women , 28 - 46 years old , performed eccentric exercise with the right m. quadriceps in an isokinetic dynamometer ( Biodex , angle velocity : 60 degrees.s-1 ) until exhaustion , in two different experiments , with an interval of 13 - 23 months . In both experiments the PCr/P(i ) ratio , dynamic muscle strength , CK and muscle pain were measured before the eccentric exercise ( day 0 ) and the following 7 d. In the second experiment daily passive stretching ( 3 times of 30 s duration , with a pause of 30 s in between ) of m. quadriceps was included in the protocol . The stretching was performed before and immediately after the eccentric exercise at day 0 , and before measurements of the dependent variables daily for the following 7 d. The eccentric exercise alone led to significant decreases in PCr/P(i ) ratio ( P < 0.001 ) and muscle strength ( P < 0.001 ) , and an increase in CK concentration ( P < 0.01 ) . All subjects reported pain in the right m. quadriceps with a peak 48 h after exercise . There was no difference in the reported variables between experiments one and two . It is concluded that passive stretching did not have any significant influence on increased plasma-CK , muscle pain , muscle strength and the PCr/P(i ) ratio , indicating that passive stretching after eccentric exercise can not prevent secondary pathological alterations 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 PURPOSE To analyze the effectiveness in reducing the number of sport injuries  after application of different strategies of preventive physiotherapy during competition periods in an America 's Cup yachting crew . METHODS A prospect i ve physiotherapy intervention study during competition periods for three seasons was conducted on an America 's Cup yachting race crew of 30 professional sailors . In the first two acts ( 2004 ) , athletes did not receive any preventive physiotherapy . In the two acts celebrated in 2005 , preventive intervention ( phase 1 ) consisted of stretching exercises before the yacht race and preventative taping . During the four acts corresponding to the 2006 season , the physiotherapy program was implemented adding articular mobilization before competition , ice baths after competition , and kinesiotaping ( phase 2 ) . In the last act and the Louis Vuitton Cup ( 2007 ) , a recovery program with " core stability " exercises , postcompetition stretching exercises , and 12 h of compressive clothing were added ( phase 3 ) . RESULTS In the preintervention phase ( 2004 ) , the rate of injured sailors/competition day was 1.66 , decreasing to 0.60 in 2007 ( phase 3 ) . The number of athletes with more than one injury was significantly reduced from 53 % ( 8 of 15 ) to 6.5 % ( 2 of 12 ) . In the preintervention period , mastmen , grinders , and bowmen showed a rate of 2.88 injuries per competition day . After phase 3 , this group only suffered 0.35 injuries per competition day . CONCLUSIONS The implementation of a program of preventive physiotherapy decreased the risk of injuries suffered during competition by an America 's Cup yacht crew CONTEXT Some research ers have suggested that an alteration of stretch perception could be responsible for the success of the contract-relax ( CR ) stretch , a stretch technique derived from proprioceptive neuromuscular facilitation ( PNF ) . OBJECTIVE This study was conducted to determine if the alteration of the stretch perception is a possible explanation for the range of motion ( ROM ) gains of the CR stretch . PARTICIPANTS Eighteen subjects performed two stretches in r and omized order : the slow stretch and the CR stretch .  MAIN OUTCOME MEASURE The stretch intensity was controlled . The stretch force was measured and compared between the slow stretch and CR stretch . RESULTS There was a significant difference between the stretch force that could be applied in the PNF stretch ( 126.0 N ) and the slow stretch ( 108.4 N ) ; P = 0.00086 . The average stretch tolerance progressively increased with successive trials from 120.6 N in the first trial to 132.4 N in the fourth trial . CONCLUSION The alteration of stretch perception plays a role in the success of the CR form of PNF stretching . At least four repetitions of the CR stretch are recommended to get the greatest ROM gain The purpose of this study was to determine the effect of different static and dynamic stretch protocol s on 20-m sprint performance . The 97 male rugby union players were assigned r and omly to 4 groups : passive static stretch ( PSS ; n = 28 ) , active dynamic stretch ( ADS ; n = 22 ) , active static stretch ( ASST ; n = 24 ) , and static dynamic stretch ( SDS ; n = 23 ) . All groups performed a st and ard 10-minute jog warm-up , followed by two 20-m sprints . The 20-m sprints were then repeated after subjects had performed different stretch protocol s. The PSS and ASST groups had a significant increase in sprint time ( p ≤ 0.05 ) , while the ADS group had a significant decrease in sprint time ( p ≤ 0.05 ) . The decrease in sprint time , observed in the SDS group , was found to be nonsignificant ( p ≥ 0.05 ) . The decrease in performance for the 2 static stretch groups was attributed to an increase in the musculotendinous unit ( MTU ) compliance , leading to a decrease in the MTU ability to store elastic energy in its eccentric phase . The reason why the ADS group improved performance is less clear , but could be linked to the rehearsal of specific movement patterns , which may help increase coordination of subsequent movement . It was concluded that static stretching as part of a warm-up may decrease short sprint performance , whereas active dynamic stretching seems to increase 20-m sprint performance Abstract Maddigan , ME , Peach , AA , and Behm , DG . A comparison of assisted and unassisted proprioceptive neuromuscular facilitation techniques and static stretching . J Strength Cond Res 26(5 ) : 1238–1244 , 2012—Proprioceptive neuromuscular facilitation ( PNF ) stretching often requires a partner . Straps are available allowing an individual to perform PNF stretching alone . It is not known if a strap provides similar improvements in the range of motion ( ROM ) as partner-assisted PNF or static stretching . The purpose of this study was to compare assisted and unassisted ( with a strap ) PNF stretching and static stretching .  Hip joint ROM , reaction time ( RT ) , and movement time ( MT ) were measured prestretching and poststretching . Thirteen recreationally active adults participated in this study . The participants were subjected to 5 different stretch interventions in a r and om order on separate days . Stretch conditions included unassisted PNF stretching using ( a ) isometric , ( b ) concentric , and ( c ) eccentric contractions with a stretch strap , ( d ) partner-assisted isometric PNF , and ( e ) static stretching . The RT , MT , dynamic , active , passive hip flexion angle , and angular velocity with dynamic hip flexion were measured before and after the intervention . The ROM improved ( p < 0.05 ) 2.6 , 2.7 , and 5.4 % , respectively , with dynamic , active static , and passive static ROM , but there was no significant difference between the stretching protocol s. There was a main effect for time ( p < 0.05 ) with all stretching conditions negatively impacting dynamic angular velocity ( 9.2 % ) . Although there was no significant effect on RT , MT showed a negative main effect for time ( p < 0.05 ) slowing 3.4 % . In conclusion , it was found that all 3 forms of active stretching provided similar improvements in the ROM and poststretching performance decrements in MT and angular velocity . Thus , individuals can implement PNF stretching techniques with a partner or alone with a strap to improve ROM , but athletes should not use these techniques before important competitions or training because of the impairment of limb velocity and MT Curry , BS , Chengkalath , D , Crouch , GJ , Romance , M , and Manns , PJ . Acute effects of dynamic stretching , static stretching and light aerobic activity on muscular performance in women . J Strength Cond Res 23(6 ) : 1811 - 1819 , 2009-The purpose of this study was to compare three warm-up protocol s-static stretching , dynamic stretching , and light aerobic activity-on selected measures of range of motion and power in untrained females and to investigate the sustained effects at 5 and 30 minutes after warm-up . A total of 24 healthy females ( ages 23 - 29 years ) attended one familiarization session and three test sessions on nonconsecutive days within 2 weeks . A within-subject design protocol with the testing investigators blinded to the subjects ' warm-up was followed . Each session started with 5 minutes of light aerobic cycling followed by pretest baseline measures . Another 5 minutes of light aerobic cycling was completed and followed by one of the three r and omly selected warm-up interventions ( static stretching , dynamic stretching , or light aerobic activity ) . The following posttest outcome measures were collected 5 and 30 minutes following the intervention : modified Thomas test , countermovement jump , and isometric time to peak force knee extension measured by dynamometer . Analysis of the data revealed significant time effects on range of motion and countermovement jump changes . No significant differences ( p > 0.05 ) were found between the warm-up conditions on any of the variables . The variation in responses to warm-up conditions emphasizes the unique nature of individual reactions to different warm-ups ; however , there was a tendency for warm-ups with an active component to have beneficial effects . The data suggests dynamic stretching has greater applicability to enhance performance on power outcomes compared to static stretching AIM The interaction between running , stretching and practice jumps during warm-up for jumping tests has not been investigated . The purpose of the present study was to compare the effects of running , static stretching of the leg extensors and practice jumps on explosive force production and jumping performance . METHODS Sixteen volunteers ( 13 male and 3 female ) participated in five different warm-ups in a r and omised order prior to the performance of two jumping tests . The warm-ups were control , 4 min run , static stretch , run + stretch , and run + stretch + practice jumps . After a 2 min rest , a concentric jump and a drop jump were performed , which yielded 6 variables expressing fast force production and jumping performance of the leg extensor muscles ( concentric jump height , peak force , rate of force developed , drop jump height , contact time and height/time ) . RESULTS Generally the stretching warm-up produced the lowest values and the run or run + stretch + jumps warm-ups produced the highest values of explosive force production . There were no significant differences ( p<0.05 ) between the control and run + stretch warm-ups , whereas the run yielded significantly better scores than the run + stretch warm-up for 
    Output:
    
Testing was performed on average 3 - 5 min after stretching , and most studies did not include poststretching dynamic activities ; when these activities were included , no clear performance effect was observed .
DS produced small-to-moderate performance improvements when completed within minutes of physical activity .
SS and PNF stretching had no clear effect on all-cause or overuse injuries ; no data are available for DS .
All forms of training induced ROM improvements , typically lasting < 30 min .
Changes may result from acute reductions in muscle and tendon stiffness or from neural adaptations causing an improved stretch tolerance .
Considering the small-to-moderate changes immediately after stretching and the study limitations , stretching within a warm-up that includes additional poststretching dynamic activity is recommended for reducing muscle injuries and increasing joint ROM with inconsequential effects on subsequent athletic performance