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Stretching: Acute and Chronic? The Potential Consequences

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summary: Stretching is commonly used by many athletes in different sports. Although acute stretching, as part of a warm-up, can enhance range of motion, it may also reduce performance. Acute stretching can reduce peak force, rate of force production, and power output. Chronic stretching may enhance performance, although the mechanism is unclear. Acute stretching has little effect on injury. However, chronic stretching (not part of warm-up) may have some injury reduction potential. (C) 2006 National Strength and Conditioning Association

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... Additional examples of dynamic stretches include arms circles, walking lunges (without weights) and medicine ball exercises. Dynamic stretching allows for flexibility activity during the rehearsal of a sport-specific movement, such as jumping (Stone, Ramsey, Kinser, O'Bryant, Ayers, & Sands, 2006). ...
... It can be argued that to most effectively prepare strength or power athletes for a specific sport activity, the pre-activity routine should readily address the concept of movement pattern specificity, but what combination of a general warm-up and stretching best prepares the athlete? The answer can be found in current research (Stone et al., 2006). ...
... A properly planned pre-activity protocol will bring about a range of physiological changes that will improve performance during training activity or competition. The flexibility literature suggests athletes should perform a "general" warm-up routine prior to activity (Cè, Margonato, Casasco, & Veisteinas, 2008;Hedrick, 1992;LaRoche, Lussier, & Roy, 2008;Mann & Jones, 1999;Ninos, 1995;Torres et al., 2008;Yamaguchi & Ishii, 2005), stretching routine prior to activity (Fredrick & Szymanski, 2001: LaRoche et al., 2008Mann & Jones, 1999), and a stretching routine post activity (Stone et al., 2006). ...
Article
The purpose of this study was to determine if NCAA Division I and III men’s basketball programs were in compliance with recommended pre- and post-activity stretching protocols. Questionnaires were sent to 500 NCAA Division I and Division III programs in the United States. Seventy-six coaches (75 males & 1 female) participated in the study. Chi-Square analysis (χ ² (3,n=69) = 42.29, p≤0.001) indicated a greater combined percentage of static/pnf/ballistic stretches (10.14%, n=7) and combination of stretches (57.97%, n=40) than expected as compared to dynamic stretches (31.89%, n=22). Participants were asked during what period (pre- or post-activity) stretching should be emphasized. The results were significantly different from expected (χ ² (4,n=76) = 129.28, p≤0.001), with a greater percentage of pre-activity stretches (26.31%, n=20) and both pre- and post-activity of stretches (60.52%, n=46) being reported as compared to post-activity stretches (13.15%, n=10). Some results seemed to be in conflict with current recommendations in the literature regarding pre-activity stretching practices.
... S tretching is commonly used by athletes in different sports. Stretching can alter the range of motion about a joint and improve flexibility (Stone et al., 2006). However, stretching as part of a warm-up may reduce performance. ...
... However, stretching as part of a warm-up may reduce performance. Most available data indicates that acute performance reduction can occur and it may be related to decreased tissue stiffness or alterations in nervous system components of the stretch-shortening cycle, such as the myototic reflex (Stone et al., 2006). These alterations in turn can result in a decreased maximum strength and explosiveness and inferior performances (Stone et al., 2006). ...
... Most available data indicates that acute performance reduction can occur and it may be related to decreased tissue stiffness or alterations in nervous system components of the stretch-shortening cycle, such as the myototic reflex (Stone et al., 2006). These alterations in turn can result in a decreased maximum strength and explosiveness and inferior performances (Stone et al., 2006). Several studies were carried out on vertical jump performance to see the effect of stretching. A. G. Nelson et al. (1996) investigated vertical jump performance after passive stretching in untrained men. ...
Article
Research background. Stretching is believed to enhance performance, reduce injury, and be an effective means of developing flexibility and alleviating muscular soreness (Shellock, Prentice, 1985; Brandy et al., 1997). A review of the current literature shows that the results of many studies conflict with others; some report that static stretching diminishes vertical jum (VJ) performance (Cornwell et al., 2001; McNeal, Sands, 2003; Wallmann et al., 2005), whereas others report that static stretching has no effect at all on VJ (Church et al., 2001; Power et al., 2004; Unick et al., 2005). Research aim, was to examine the effects of different durations of stretching on performance and to find the stretching durations that affect the performance negatively or positively. Research methods. The subjects of the study were 27 rhythmic gymnasts with the mean age of 10.00 ± 1.2 years. The subjects as a whole group participated in two different stretching programs on nonconsecutive days to eliminate the effect of individual differences on the performance. On the first day, athletes were asked to warm up by 5 minute jogging after the pretest was administered. The posttest measured the vertical jump performance after athletes stayed inactive for 20 minutes. They rested for a day and on the third day, their performance was measured again. After the 5 minute warm-up period, 10 repetitions of 15 seconds static stretching exercises for hip flexor, hamstring and gastrocnemius muscle groups were followed by the posttest. Moreover, on the fifth day 30-second exercises were repeated five times on the same type of muscles. The participants in this investigation were tested in individual vertical jump performances following warm-up only, warm-up plus 15 seconds static stretching, and warm-up plus 30 seconds. Research results. Results of a one-way repeated-measures ANOVA indicated a nonsignificant difference for vertical jump performance (F = 2.052; p > 0.05). Discussion and conclusions. Stretching exercises are referred in rhythmic gymnastics more intensively than other sports. Relevant literature displays fewer stretching repetitions and durations. These durations and repetitions may not be realistic and practical for rhythmic gymnasts. Therefore, the durations and repetitions utilized in this study are considered more appropriate for rhythmic gymnastics trainings. Rhythmic gymnasts may make use of duration and repetitions determined in this study that will not affect their performance. Keywords: anaerobic power, gymnastics, exercise.
... Coaches, as well as other specialists, including physiotherapists, recommend that players and patients stretch before performing strength and speed exercises. However, authors of numerous studies suggest that stretching exercises before the main motor task do not decrease the risk of injury [4,6,7]. They also claim that static stretching before the main exercises has a detrimental influence on the force and speed of muscle contraction. ...
... The mechanisms which are responsible for loss of strength and power after static stretching have been presumed to involve both mechanical and neurophysiological changes [7,21]. Intense stretching exercises lead to damaged contractile proteins in skeletal muscles which reduce their capability for regeneration after physical effort. ...
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Recent data, especially related to the molecular structure of muscle tissue and the neurophysiological processes that control muscular speed and force have questioned the benefits of stretching exercises performed prior to dynamic physical activities such as sprinting or jumping. On the other hand strength exercises with various types of muscle contraction and different training loads have proven effective in developing running speed and jumping performance. The present work attempted to verify the hypothesis concerning the detrimental influence of stretching on running speed and anaerobic power of lower limbs, while confirming the benefits of strength exercises on these motor abilities. The main objective of the study was to evaluate the short-term effects of stretching and strength exercises on running speed and jumping performance in competitive basketball players. The results showed significant changes in all of six variables used to evaluate lower limb power and running speed. Vertical jump performance showed increased tendencies in a microcycle without stretching, yet with strength exercises focused on lower limb extensors and flexors. Take-off speed, maximal jump height, work output and power during this microcycle were significantly higher in comparison to a weekly cycle were stretching was incorporated in the warm-up and prior to testing. In the case of running speed, the 3 treatments revealed significant differences, yet once again strength exercises compared to stretching allowed reaching of faster times for the 5 and 20 m sprint, respectively.
... According to the traditional approach, the warmup should include activities that increase muscle flexi- bility [32] in order to improve the joint ranges of motion (ROM). Acute and chronic changes in flexibility refer to the period before or after the practice of physical activity , respectively [1,5,18,31]. Flexibility training can be of maximum intensity (flexibilizing) or of a sub-maximum one (stretching); the first, conducted just under the pain threshold, leads to attaining maximum range of motion (ROM), the other form employs movements in the upper normal range of motion [35]. In practice, there are 4 different protocols for flexibility training – static, ballistic and dynamic stretching, and proprioceptive neuromuscular facilitation (PNF, [20]). ...
... Static stretching, or slow movements that gradually lengthen muscles to an elongated position, hold for 15 to 60 s, is the most widely used protocol [1]. Although a prolonged static stretching may increase muscle performance [30], a number of studies showed that acute stretching (maximum stretching preceding physical activity) may reduce it, particularly in terms of maximal and explosive muscle strength [31,33,37] . However , other authors did not observe that latter effect [14, 27]. ...
Article
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Acute effects of static stretching on muscle strength Study aim : To assess the effects of static passive maximal stretching on muscle performance in order to clarify the existing controversies. Material and methods : Two randomly selected groups of the Brazilian Air Force personnel were studied: experimental (n = 15), subjected to 3 bouts of static passive stretching exercises of wrist flexors and extensors (beyond a mild discomfort). Every bout lasted 10 s and was followed by a 30-s rest. The control group (n = 15) performed no exercises. Muscle strength was measured with a handgrip dynamometer before and 20 min after the test. Results : Subjects from the experimental group had the pre-exercise handgrip strength significantly higher than postexercise (by about 7%; p<0.01). No significant decrease was noted in the control group. Conclusions : Static passive stretching induces decreases in muscle strength.
... Similarly, Cramer (2006) found no effect on peak torque of leg extensors from static stretching. The current trend shows that static stretching tactics are better suited following activity, not before it (Anderson, Beauliue, Cornelius, Dominquez, Prentice, & Wallace, 1984; Egan, Cramer, Massey, & Marek, 2006; Nelson, & Brandy, 2008; Stone, Ramsey, O'Bryant, Ayers, & Sands, 2006; Swanson, 2008). Research supports that gains in range of motion can be achieved if static stretching is performed consistently post-activity as a part of the ...
... Current research indicates that athletes should perform staticstyle stretching following exercise (Anderson, Beauliue, Cornelius, Dominquez, Prentice, & Wallace, 1984; Egan, Cramer, Massey, & Marek, 2006; Nelson, & Brandy, 2008; Stone, Ramsey, O'Bryant, Ayers, & Sands, 2006; Swanson, 2008). The results from this study indicate that 49 of the responders had their athletes perform post-activity stretching. ...
Article
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The purpose of this study was to determine if NCAA Division I women's volleyball programs were in compliance with suggested current pre-and post-activity stretching protocols. Questionnaires were sent to NCAA division I women's volleyball programs in the United States. Fifty six coaches (23 males & 33 females) participated in the study. Some results seemed to conflict with current suggested practices for pre-activity stretching. The results of this study indicate that certification may not influence how well research guidelines are followed. Further research is needed to delineate how these factors affect coaching decisions.
... Similarly, reduced muscular power, rate of force development, peak isokinetic torque and diminished performance of complex movements involving SSCs [44,59,63] have questioned the efficacy of antecedent stretching [46]. Although the relative importance of factors such as intensity, mode of stretching and the optimal way of incorporating it into the warm-up routine has yet to be fully determined in the extent of acute impairment that might occur [44], even detrimental effects of 0-4 % observed in sprint and jump performance could impact adversely on competitive outcomes [68]. By contrast, chronic effects of stretching aimed at increasing range of motion (ROM) over an extended period appear to be beneficial to performances involving the SSC [59,63]. ...
Article
Background: Alongside its role in athletic conditioning, stretching has commonly been integrated in warm-up routines prior to athletic performance. Numerous studies have reported detrimental acute effects on strength following stretching. Consequently, athletes have been recommended to discontinue stretching as part of warm-ups. In contrast, studies indicate that chronic stretching performed as a separate bout from training or competition may enhance performance. However, the influence of stretching on complex performances has received relatively little attention. Objective: The purpose of this study was to review both the acute and chronic effects of stretching on performances involving the stretch-shortening cycle (SSC). Methods: A systematic search for literature was undertaken (January 2006-December 2012) in which only randomized controlled trials (RCTs) or studies with repeated measures designs were included. The Physiotherapy Evidence Database (PEDro) rating scale was used for quality assessment of the evidence. Results: The review included 43 studies, from which conflicting evidence emerged. Approximately half of the studies assessing the acute effect of static stretching reported a detrimental effect on performance, while the remainder found no effect. In contrast, dynamic stretching showed no negative effects and improved performance in half of the trials. The effect size associated with static and dynamic stretching interventions was commonly low to moderate, indicating that the effect on performance might be limited in practice. Factors were identified that might have contributed to the conflicting results reported across studies, such as type of SSC performance and carrying out dynamic activity between the stretching bout and performance. Few studies since 2006 have addressed the chronic effect of stretching on functional and sports performance. Although negative effects were not reported, robust evidence of the overall beneficial effects within current bibliographic databases remains elusive. Plausible mechanisms for the observed effects from stretching are discussed, as well as possible factors that may have contributed to contradictory findings between studies. Limitations: Considerable heterogeneity in study design and methods makes comparison between studies challenging. No regression analysis of the contribution of different predictors to variation between trials had previously been performed. Hence, predictors had to be selected on the basis of a qualitative analysis of the predictors that seemed most influential, as well as being identified in previous narrative reviews. Conclusion: Different types of stretching have differential acute effects on SSC performances. The recommended volume of static stretching required to increase flexibility might induce a negative acute effect on performances involving rapid SSCs, but the effect sizes of these decrements are commonly low, indicating that the acute effect on performance might be limited in practice. No negative acute effects of dynamic stretching were reported. For athletes that require great range of motion (ROM) and speed in their sport, long-term stretching successfully enhances flexibility without negatively affecting performance. Acute dynamic stretching may also be effective in inducing smaller gains in ROM prior to performance without any negative effects being observed.
... In our study, WBV provided additional beneficial effects in improving muscle flexibility and range of motion, when added to traditional flexibility stretching programs. 33,34 Experimental evidence showed that the vibratory stimulus exerts its effect by increasing neuromuscular activity. 35 During WBV, the Ia afferents become more sensitive to vibration with respect to other afferents, such as Golgi tendon organs (GTO) and group II afferents fibres. ...
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Background: The current study aimed to investigate and compare the influences of global postural rieducation techniques (GPR), stretching exercises on a whole-body vibration platform (WBV), and static stretching exercises on hamstrings flexibility in elite soccer players. Methods: 24 professional soccer players were randomly assigned to either global postural re-education (N.=8), stretching on whole-body vibration group (N.=8) or static stretching (N.=8), during the first 4 weeks of the precompetitive season. Assessment of hamstring muscle flexibility was performed using a straight leg raise test. All participants were assessed three times: at baseline, at the end of the study protocol and 14 days after the end of the study protocol. Results: The short-term increase in hamstring muscle flexibility was observed in all 3 groups, without significant differences among groups. However, after 14 days from the end of the interventions only the WBV group maintained the flexibility level achieved just at the end of the protocol with no significant changes in both legs whereas a significant decrease in the SLRT in GPR and SS groups, in right and left legs (GPR, P=0.002; P=0.015; SS, P=0.0001; P=0.0001), was observed. Conclusions: These results would suggest that GPR, static stretching on whole-body vibration and static stretching techniques all improve hamstring muscle flexibility, but only stretching on WBV maintains the effect over time in professional soccer players.
... Although there are many types of stretching exercises used during the warm-up (27), static stretching is the easiest and most frequently used stretching method. The intent of static stretching during the warm-up is to improve the range of motion (ROM) of a joint (26) to allow maximal force production, is the main reason for increasing performance in the activities that follow, and reduce the possibility of muscle tears during activity. However, numerous studies have shown that static stretching can induce muscle strength and force deficits (1,3,5,7,8,10,13,16). ...
Article
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Amiri-Khorasani, M, MohammadKazemi, R, Sarafrazi, S, Riyahi-Malayeri, S, and Sotoodeh, V. Kinematics analyses related to stretch-shortening cycle during soccer instep kicking after different acute stretching. J Strength Cond Res 26(11): 3010-3017, 2012-The purpose of this study was to examine the effects of static and dynamic stretching within a preexercise warm-up on angular velocity of knee joint, deepest knee flexion (DKF), and duration of eccentric and concentric contractions, which are relative to the stretch-shortening cycle (SSC) during instep kicking in professional soccer players. The kicking motions of dominant legs were captured from 18 Olympic professional male soccer players (height: 180.38 ± 7.34 cm; weight: 69.77 ± 9.73 kg; age: 19.22 ± 1.83 years) using 4 digital video cameras at 50 Hz. There was a significant difference in the DKF after the dynamic stretching (-3.22 ± 3.10°) vs. static stretching (-0.18 ± 3.19°) relative to the no-stretching method with p < 0.001. Moreover, there was significant difference in eccentric duration after the dynamic stretching (0.006 ± 0.01 seconds) vs. static stretching (-0.003 ± 0.01 seconds) relative to the no-stretching method with p < 0.015. There was a significant difference in the concentric duration after the dynamic stretching (-0.007 ± 0.01 seconds) vs. static stretching (0.002 ± 0.01 seconds) relative to the no-stretching method with p < 0.001. There was also a significant difference in knee angular velocity after the dynamic stretching (4.08 ± 3.81 rad·s) vs. static stretching (-5.34 ± 4.40 rad·s) relative to the no-stretching method with p < 0.001. We concluded that dynamic stretching during warm-ups, as compared with static stretching, is probably the most effective way as preparation for the kinematics characteristics of soccer instep kick, which are relative to the SSC.
... Preparation for agility and other performance training should involve both long-and short-term preparations. Longterm preparation may include a well-developed agility training program, while short-term preparation should include a warm-up (3,4,32). Often, stretching is performed as part of a warm-up prior to physical exertion. ...
Article
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The purpose of this study was to examine the effects of static, dynamic, and the combination of static and dynamic stretching within a pre-exercise warm-up on the Illinois agility test (IAT) in soccer players. Nineteen professional soccer players (age = 22.5 ± 2.5 years, height = 1.79 ± 0.003 m, body mass = 74.8 ± 10.9 kg) were tested for agility performance using the IAT after different warm-up protocols consisting of static, dynamic, combined stretching, and no stretching. The players were subgrouped into less and more experienced players (5.12 ± 0.83 and 8.18 ± 1.16 years, respectively). There were significant decreases in agility time after no stretching, among no stretching vs. static stretching; after dynamic stretching, among static vs. dynamic stretching; and after dynamic stretching, among dynamic vs. combined stretching during warm-ups for the agility: mean ± SD data were 14.18 ± 0.66 seconds (no stretch), 14.90 ± 0.38 seconds (static), 13.95 ± 0.32 seconds (dynamic), and 14.50 ± 0.35 seconds (combined). There was significant difference between less and more experienced players after no stretching and dynamic stretching. There was significant decrease in agility time following dynamic stretching vs. static stretching in both less and more experienced players. Static stretching does not appear to be detrimental to agility performance when combined with dynamic warm-up for professional soccer players. However, dynamic stretching during the warm-up was most effective as preparation for agility performance. The data from this study suggest that more experienced players demonstrate better agility skills due to years of training and playing soccer.
... An increase that may have acute or chronic expression. 2 Aim. This study sought to compare the level of hydroxyproline (HP) and the electric signal and the amplitude of the movements in sedentary youths submitted to stretching and neural mobilization programs. ...
Article
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Aim. This study sought to compare the level of hydroxyproline (HP) and the electric signal and the amplitude of the movements in sedentary youths submitted to stretching and neural mobilization programs. Methods. The sample consisted of sedentary students divided into three groups: a neural mobilization group (NMG; n=15; age=22; 3 years; BMI=24.75;3.09), a static stretching group (SSG; n=15; age=23; 4 years; BMI=25; 4.33) and a control group (CG; n=15; age: 24; 4 years; BMI: 23.91; 3.09). Nordim (HP), electromyography - EMG(electric activity on the femoral biceps) and electrogoniometer (angle of waist) methods were used for this evaluation. Static stretching was performed by means of passive distension over six seconds, and neural mobilization was conducted in a direct, oscillatory and straining manner for 60 seconds. The p≤0.05 level was adopted for statistical significance. Satisfactory results were found for HP: intra-group analysis, on the NMG (@= 7.38 mg/24h; P=0.0001) and on the SSG (@= 3.47 mg/24h; P=0.002) and for the inter-group post-test analysis, on the NMG vs. SSG (@= 4.37 mg/24h; P=0.006) and on the NMG vs. CG (@=7.2 mg/24h; P=0.0001). For electrogoniometry, better results were found: for the intra-group analysis, on the NMG (@=17.35; P=0.0001) and on the SSG (@=9.81; P=0.005) and for the inter-group post-test, on the NMG vs. SSG (@=8.96; P=0.027) and on NMG vs. CG (@=16.09; P=0.0001). Results. A significant decrease was observed for the electromyography: for the intra-group analysis, on the NMG (@=-10.99; P=0.001) and on the SSG (@=-7.35; P=0.033) and for the inter-group analysis, on the NMG vs. CG (@=-9.89; P=0.033). Conclusion. It may be concluded that both trainings obtained satisfactory results, increasing the level of HP and the amplitude of movement and reducing muscular electric activity. However, neural mobilization was observed to be more effective than the other modalities.
... It has been documented that static stretching alone may have a deleterious effect on muscle strength and power attributes (Avela, Kyrolainen, & Komi, 1999;Church, Wiggins, Moode, & Crist, 2001;Stone et al., 2006;Young & Behm, 2003). Conversely, flexibility and explosive power have been enhanced by vibration . ...
Article
Abstract Since the turn of the 21st century, there has been a resurgence of vibration technology to enhance sport science especially for power and force development. However, vibration exercise has been trialled in other areas that are central to athlete performance such as warm-up, flexibility and sprint speed. Therefore, the aim of this review was to attempt to gain a better understanding of how acute and short-term vibration exercise may impact on warm-up, flexibility and sprint speed. The importance of warming up for sporting performance has been well documented and vibration exercise has the capability to be included or used as a standalone warm-up modality to increase intramuscular temperature at a faster rate compared to other conventional warm-up modalities. However, vibration exercise does not provide any additional neurogenic benefits compared to conventional dynamic and passive warm-up interventions. Vibration exercise appears to be a safe modality that does not produce any adverse affects causing injury or harm and could be used during interval and substitution breaks, as it would incur a low metabolic cost and be time-efficient compared to conventional warm-up modalities. Acute or short-term vibration exercise can enhance flexibility and range of motion without having a detrimental effect on muscle power, however it is less clear which mechanisms may be responsible for this enhancement. It appears that vibration exercise is not capable of improving sprint speed performance; this could be due to the complex and dynamic nature of sprinting where the purported increase in muscle power from vibration exercise is probably lost on repeated actions of high force generation. Vibration exercise is a safe modality that produces no adverse side effects for injury or harm. It has the time-efficient capability of providing coaches, trainers, and exercise specialists with an alternative modality that can be implemented for warm-up and flexibility either in isolation or in conjunction with other conventional training methods.
... Most of the individuals in this study exercised at least three times a week. Therefore, it could be assumed that our participants were already at their ideal flexibility or optimal length (14) and that is why we failed to see a significant improvement in hamstring ROM. Future studies should either 1) include more participants in each stretching group , 2) extend the stretching protocols to see a measurable increase in hamstring flexibility ...
Article
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Preactivity stretching is commonly performed by active individuals as part of their warm-up routine. While both static and dynamic stretching are techniques utilized by the everyday exerciser, it has been questioned as to whether these types of stretching protocols can be harmful or beneficial to anaerobic exercise performance. The current literature on stretching has also been biased toward athletes. Therefore, the purpose of this study was to investigate whether three weeks of either static or dynamic hamstring stretching affects range of motion (ROM) and anaerobic exercise performance in recreationally active individuals. Twenty-two healthy college-aged students were randomly divided into three groups; static stretching (n=9), dynamic stretching (n=8), or no-stretch control (n=5). Participants completed three weeks of the stretching protocol with measurements taken before and after the stretching regimen. ROM of the hamstrings were measured via the sit and reach test and the active knee extension test (AKET) while three variables of anaerobic performance (horizontal jump, vertical jump, and 50 meter sprint) were analyzed. Statistical analysis showed no significant differences (p<0.05) between groups for the horizontal jump (p=0.261), vertical jump (p=0.983), or the 50 meter sprint (p=0.899). Furthermore, three weeks of either static or dynamic hamstring stretching did not improve ROM in our active volunteers. Therefore, based on the current investigation, neither static nor dynamic stretching appears to impact anaerobic exercise performance.
... Although acute stretching exercises can enhance ROM, it may also reduce peak force, rate of force production and power output (Stone et al., 2006). Recent studies conducted on the acute effects of static stretches and PNF have shown that these stretching techniques may result in a significant reduction or no change on jump performance and on power output (Power et al., 2004;Little and Williams, 2006;Wallmann et al., 2005;Unick et al., 2005;Knudson et al., 2001;Young and Behm, 2003;Church et al., 2001). ...
Article
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The purpose of the present study was to investigate the long-term effects of two different stretching techniques on the range of motion (ROM) and on drop jump (DJ). DJ scores were assessed by means of a contact mat connected to a digital timer. ROM was measured by use of a goniometer. The training was carried out four times a week for 6 weeks on 10 subjects as passive static stretching (SS), and on 9 subjects as contract-relax PNF (CRPNF) stretching. The remaining nine subjects did not perform any exercises (control group). One-way Analysis of Variance (ANOVA) results indicated that the differences among groups on DJ were not statistically different (F(2,27)=.41, p>.05). ROM values were significantly higher for both stretching groups, while no change was observed for the control group. In conclusion, static and proprioceptive neuromuscular facilitation (PNF) stretching techniques improved the ROM, but neither of the stretching exercises had any statistically significant effect on the DJ scores.
... The literature is scarce on this topic, to the best of the authors' knowledge, there are only two review studies (Rubini, Costa, & Gomes, 2007;Stone et al., 2006) that attempted to elucidate the role of FT on MP. However, both studies employed a narrative approach and provided insufficient information on the topic. ...
Article
The aim of the current study was to investigate the influence of chronic stretching on muscle performance (MP) by a systematic review. The search strategy included MEDLINE, PEDro, Cochrane CENTRAL, LILACS, and manual search from inception to June 2016. Randomized and controlled clinical trials, non-randomized, and single group studies that have analyzed the influence of flexibility training (FT) (using any stretching technique) on MP were included. Differently, studies with special populations (children, elderly, and people with any dysfunction/ disease), and articles that have used FT protocols shorter than three weeks or 12 sessions were excluded. The MP assessment could have been performed by functional tests (e.g. jump, sprint, stretch-shortening cycle tasks), isometric contractions, and/or isotonic contractions. Twenty-eight studies were included out of 513. Seven studies evaluated MP by stretch-shortening cycle tasks, Ten studies evaluated MP by isometric contractions, and 13 studies assessed MP by isotonic contractions. We were unable to perform a meta-analysis due to the high heterogeneity among the included studies. In an individual study level analysis, we identified that 14 studies found positive effects of chronic stretching on MP. The improvements were observed only in functional tests and isotonic contractions, isometric contractions were not affected by FT. Therefore, FT might have an influence on dynamic MP. However, more studies are necessary to confirm whether FT can positively affect MP.
... Flexibility is also an important fundamental factor that is part of the exercise prescription with the objective to increase physical fitness and conditioning (2, 4,35). The increase in range of motion (ROM) throughout the musculoskeletal system can be considered acute or chronic (38). Flexibility training may be prescribed with different intensity, submaximum stretching or maximum stretching using static, dynamic and proprioceptive neuromuscular facilitation (PNF) methods (19). ...
Article
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The purpose of this study was to analyze the hydroxyproline level (HP), electromyography signal (EMG), and range of motion in sedentary young subjects submitted to static stretching and proprioceptive neuromuscular facilitation (PNF). The sample was randomly divided into: (a) PNF; (b) static stretching; and (c) control group. For data assessment, the study used the Nordim method (HP); biceps femoris electromyography and electrogoniometry (hip angle) value. For HP results, FG (P=0.0001) and SG (P=0.002) showed significant increase compared to the pre-test. At 24 hrs post, the FG (P=0.018) and SG (P=0.005) showed significant increase in comparison to CG. For EMG results, FG (P=0.0001) and SG (P=0.033) demonstrated significantly lower muscle activity in the post-test. Inter-variable comparison showed a significant inverse correlation between EMG and HP (r = -0.624, P=0.013) and between EMG and goniometry (r = -0.562, P=0.029). The findings indicate that both stretching methods promote an increase in hydroxyproline levels and reduced electric activity in the biceps femoris muscle.
... Flexibility is also an important fundamental factor that is part of the exercise prescription with the objective to increase physical fitness and conditioning (2, 4,35). The increase in range of motion (ROM) throughout the musculoskeletal system can be considered acute or chronic (38). Flexibility training may be prescribed with different intensity, submaximum stretching or maximum stretching using static, dynamic and proprioceptive neuromuscular facilitation (PNF) methods (19). ...
Article
Mafra O, Senna GW, Leal SMO, Conceição MCS, Meza EA, Guimarães AC, Maia BLC, Dantas EHM. Hydroxyproline Concentration, Electrogoniometry, EMG Responses, and Correlations after Different Stretching Methods, JEPonline 2017;20 (6):55-65. The purpose of this study was to analyze the hydroxyproline level (HP), electromyography signal (EMG), and range of motion in sedentary young subjects submitted to static stretching and proprioceptive neuromuscular facilitation (PNF). The sample was randomly divided into: (a) PNF; (b) static stretching; and (c) control group. This study used the Nordim method (HP); biceps femoris electromyography and electrogoniometry (hip angle) value to assess the data. For HP results, FG (P=0.0001) and SG (P=0.002) showed significant increase compared to the pre-test. At 24 hrs post, the FG (P=0.018) and SG (P=0.005) showed significant increase in comparison to CG. For EMG results, FG (P=0.0001) and SG (P=0.033) demonstrated significantly lower muscle activity in the post-test. Inter-variable comparison showed a significant inverse correlation between EMG and HP (r =-0.624, P=0.013) and between EMG and goniometry (r =-0.562, P=0.029). The findings indicate that both stretching methods promote an increase in hydroxyproline levels and reduced electric activity in the biceps femoris muscle.
... Para considerações relacionadas ao grau de flexibilidade, foi identificado desempenho inferior ao reportado pela literatura (23,4 ± 8,3 cm versus 44,2 ± 7,1 cm) para medidas a partir do teste Sentar e alcançar (Maud, 1983). Embora não haja relação entre flexibilidade e prevenção de lesões desportivas agudas, a melhoria dessa variável tende a diminuir a chance de agravos musculares em médio e longo prazo (Stone et al., 2006). Nesse sentido, vale lembrar que há elevado percentual de distensões e contraturas musculares decorrentes da prática do rúgbi (Yard & Comstock, 2006). ...
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The benefits and possible detriment of resistance training have been noted extensively in the literature. Although the benefits of resistance training are well known, many professionals fail to heed scientific advice or follow appropriate recommendations for resistance training in adolescents. When developing a resistance training program for adolescents, be cognizant of any pre-existing health conditions and experience level of the adolescent. For strength training, the adolescent should begin with exercises that involve all major muscle groups with relatively light weight, one to three sets of 6 to 15 repetitions, 2 to 3 non-consecutive days per week. As the adolescent becomes more experienced, gradually increase loads and add multijoint exercises. Each exercise session should be properly supervised for safety, and to provide feedback on technique and form, regardless of the resistance training experience of the adolescent. This article reviews the guidelines for resistance training for health-related fitness for adolescents.
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The purpose of this study was to examine the effect of different conditions of Whole Bode Vibration (WBV) on flexibility and jumping performance on artistic gymnasts. Twelve well trained gymnasts volunteered to participate in this study. They were performed under two different condition protocols. The first was examined as WBV combined with static stretching condition (WBVSS) and the second was examined as WBV. Flexibility and explosive strength tests were performed initially (Pre), immediately after the intervention (Post 1), 15 minutes (Post 15) and 30 minutes after the end of the intervention program (Post 30). A two-way ANOVA (condition * trials) with repeated measures on both factors was used. The level of significance was set at p < 0.05. Univariate analyses with Bonferroni adjustments (0.05/6) were selected as post hoc tests. The results revealed no significant interaction between conditions and trials in all examined variables (p>0.05). However, significant difference was found with respect to Sit&Reach test between pre and post 1 measurement (p=0.002). Further, the percentage improvement of WBV was greater in SJ and CMJ variables compared to WBVSS condition. Conclusively, both conditions (WBVSS and WBV) were effective on flexibility and jumping performance on artistic gymnasts and that each of them has a specific effect on the examined variables.
Article
This study aimed to investigate the effects of stretch training on stress associated with care work. We examined changes in saliva levels of cortisol and immunoglobulin (Ig) A, grip strength, body anteflexion, depression, mood, and low back pain level in caregivers. Forty subjects (11 men, 29 women) without any medication or illnesses affecting sleep and/or mental health participated in this study. Subjects were randomly allocated to either a training intervention group or a non-training control group. The exercise program involved stretching according to lower back pain prevention techniques and poses. Subjects attended a weekly seminar during the 4-week intervention to learn proper stretching techniques. The intervention group was instructed to perform the program immediately before bedtime every day. The rate of compliance with the program was 81.4% in men and 85.5% in women. Statistical analysis was performed separately for each sex. Significant interactions with two factors (intervention and time progress) were identified for body anteflexion and cortisol level in women. The intervention group showed a significantly greater increase in body anteflexion than the control group at the end of the intervention period. Cortisol levels increased over the study period in the control group, but decreased in the intervention group. There was no significant interaction in either variable in men. These results suggest that stretching exercise programs offer a practical method for use in daily life, and may be effective for promoting greater improvements in stress response by improving flexibility in female caregivers. © 2015, Meiji Life Foundation of Health and Welfare. All rights reserved.
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This book is for therapists involved in exercise therapy for the prevention and treatment of disease. It covers exercise assessment, current prescription guidelines, precautions, exercise design and clinical case studies. The book also includes exercises to increase strength, power, local muscle endurance, range of movement and aerobic capacity and will be relevant to all areas of therapy practice. In addition to the general guidelines, considerations for exercise groups and exercise at home as well as exercise in special patient populations are addressed. This allows therapists who are expert in one area to become familiar with exercise prescription in another. The book underpins therapeutic exercise in general and also addresses specific considerations for particular clinical situations within current guidelines and practical considerations. Underpinning exercise physiology Physical principles of exercise design Guidelines for exercise training Clinical exercise prescription Limitations to exercise in common conditions Example case studies.
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BACKGROUND: This study investigated the association between previous experience with strength training under proper supervision and knowledge of stretching. METHODS: A questionnaire-based survey was conducted among university students (N.=870) to clarify the relationships between their experience of strength training under appropriate supervision, and knowledge of sit-and-reach stretching (SR-stretching). RESULTS: This study revealed that more than 50% of the participants performed SR-stretching periodically, even if they did not have any experience with strength training under appropriate supervision. the participants who lacked experience with strength training under supervision had made significantly greater attempts to consciously stretch non-stretched parts (i.e. abdominals, anterior legs, arms, and so) upon being shown the SR-stretching picture than those who had experienced strength training under supervision. CONCLUSIONS: These results suggest that although the individuals performed SR-stretching periodically, those who had never experienced strength training under supervision may not have properly understood the stretching method. Therefore, to enhance the benefits of stretching, individuals should be instructed to perform the technique correctly and under appropriate supervision. Furthermore, more than 70% of those who do not have regular exercise habits perceived that non-stretched parts were being stretched. it is suggested that appropriate supervision is of greater importance for participants without regular exercise habits who begin exercise.
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In recent years, it has been suggested that exercise using whole body vibration (WBV) platforms may increase muscle activity and subsequently enhance muscle performance in both acute and chronic conditions. WBV platforms produce frequencies ranging from 15-60 Hz and vertical displacements from ~1-11 mm, resulting in accelerations of ~2.2-5.1 g. Acute exposure to WBV has produced mixed results in terms of improving jump, sprint, and measures of muscle performance. With WBV training, younger fit subjects may not experience gains unless some type of external load is added to WBV exercise. However, sedentary and elderly individuals have demonstrated significant gains in most measures of muscle performance, similar with comparable traditional resistance exercise training programs. WBV training also has demonstrated gains in flexibility in younger athletic populations and gains or maintenance in bone mineral density in postmenopausal women. These promising results await further research to establish preferred WBV training parameters.
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Descriptive study to compare relationships between muscle performance measures in 2 subject groups. To determine the relationships between plantar flexor (PF) muscle stiffness, strength (concentric peak torque), and dorsiflexion (DF) range of motion (ROM) in subjects with diabetes who have peripheral neuropathy (n = 17, 10 men, 7 women; age = 58 +/- 11 years) and age-matched controls (n = 17, 10 men, 7 women; age = 62 +/- 6 years). The relationships between muscle stiffness, strength, and joint ROM have not been clearly established. Furthermore, the effect of neuromuscular pathology on these relationships is unknown. PF stiffness and strength measurements were obtained with an isokinetic dynamometer. DF ROM was measured with a goniometer. A Pearson correlation matrix was constructed for each subject group using stiffness, strength, and ROM variables. The percent contribution of passive torque to total torque was computed at 2 joint angles. In subjects with diabetes and peripheral neuropathy (DM-PN) peak concentric PF torque was positively correlated with passive torque at 5 degrees DF (r = 0.77), Stiffness #1 (r = 0.58), and Stiffness #2 (r = 0.50). The percentage of passive PF torque at 5 degrees DF was greater in subjects with DM-PN, compared to control subjects (29.3 +/- 9.4% versus 12.6 +/- 5.9%). The positive correlation between PF stiffness and strength, and the greater percentage of passive PF torque in subjects with DM-PN suggest that patients with decreased strength may use passive torque to maximize total torque. Therefore, treatment methods designed to decrease stiffness should be used cautiously.
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When the force applied to a muscle exceeds the force produced by the muscle it will lengthen, absorbing mechanical energy. These eccentric contractions, which result in both braking and storing elastic recoil energy in normal locomotion, require very little metabolic energy, yet they are characterized by high force production.
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A popular part of many athletes pre-game regime is to stretch. We examined whether a pre-injury stretching protocol could prevent acute contraction-induced injury. The in situ extensor digitorum longus (EDL) muscle of an anesthetized mouse (80 mg/kg intra-peritoneal) was used. Damage to the muscle from eccentric contraction-induced injury was quantified by the deficit in tetanic force production, and was not confounded by metabolic fatigue. The force deficits resulting from eccentric contractions alone (E) were compared with the force deficits resulting from a protocol that consisted of a stretch before the eccentric contractions (S + E). The pre-injury stretch was performed to 5% L o strain, at a velocity of 0.5 mm/s. The muscle was held in the stretch position for 1 min, then slowly released. Eccentric contraction protocols (excursion ≥ 24% L o) resulted in pronounced force deficits that increased with the excursion amplitude of the eccentric contraction. The eccentric contractions also resulted in an average right shift of 2 ± 0.53% in the length–force relationship (t-test, P = 0.0001). The regression lines for the E (eccentric contraction only) and S + E (stretch and eccentric contractions) treatments did not differ from one another for either force deficit (ANCOVA, P = 0.82) or work deficit (ANCOVA, P = 0.12). Therefore, the pre-injury stretch protocol did not reduce the force deficit or the work deficit resulting from contraction-induced injury.
Article
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During normal animal movements, the forces produced by the locomotor muscles may be greater than, equal to or less than the forces acting on those muscles, the consequences of which significantly affect both the maximum force produced and the energy consumed by the muscles. Lengthening (eccentric) contractions result in the greatest muscle forces at the lowest relative energetic costs. Eccentric contractions play a key role in storing elastic strain energy which, when recovered in subsequent contractions, has been shown to result in enhanced force, work or power outputs. We present data that support the concept that this ability of muscle to store and recover elastic strain energy is an adaptable property of skeletal muscle. Further, we speculate that a crucial element in that muscle spring may be the protein titin. It too seems to adapt to muscle use, and its stiffness seems to be 'tuned' to the frequency of normal muscle use.
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The results of previous research have shown that passive muscle stretching can diminish the peak force output of subsequent maximal isometric, concentric and stretch-shortening contractions. The aim of this study was to establish whether the deleterious effects of passive stretching seen in laboratory settings would be manifest in a performance setting. Sixteen members (11 males, 5 females) of a Division I NCAA track athletics team performed electronically timed 20 m sprints with and without prior stretching of the legs. The experiment was done as part of each athlete's Monday work-out programme. Four different stretch protocols were used, with each protocol completed on a different day. Hence, the test period lasted 4 weeks. The four stretching protocols were no-stretch of either leg (NS), both legs stretched (BS), forward leg in the starting position stretched (FS) and rear leg in the starting position stretched (RS). Three stretching exercises (hamstring stretch, quadriceps stretch, calf stretch) were used for the BS, FS and RS protocols. Each stretching exercise was performed four times, and each time the stretch was maintained for 30 s. The BS, FS and RS protocols induced a significant (P < 0.05) increase (approximately 0.04 s) in the 20 m time. Thus, it appears that pre-event stretching might negatively impact the performance of high-power short-term exercise.
Article
It has been shown that fifteen minutes of locally applied cycloid vibration of low amplitude and frequency is equally as effective as a fifteen minute programme of flexibility exercises in increasing short term mobility of the hip flexors. It is suggested that this mobility change may occur as a result of improved muscle relaxation.
Article
The sample for the study involved 12 volunteer male, active but not specially trained secondary school students. They averaged 15.33 years with a mean height of 168.20 cm, and a mean mass of 55.08 kg. Changes, if any, in the mechanical properties (MVC, half-relaxation time, fast isometric contraction, concentric contraction of the knee extensors) and flexibility of the hip joints were studied. The subjects executed passive, purely slow stretching as well as range-of-motion flexibility exercises for the knee extensors and the hip joints for 7 weeks three times a week. Pre- and post-measurements for flexibility and stride frequency on the spot showed significant improvement as did half-relaxation time, fast isometric force development, and speed of concentric contractions when low loads were to be overcome. In addition to studies in which improvements reported were attributed to and related to myoelectrical, reflex, and connective tissue changes, in the present study it was concluded that stretching exercises influence intrinsic muscle mechanical character along with a simultaneous improvement in range of motion of the joints exercised.
Article
This study investigated the effect of muscle stretching during warm-up on the risk of exercise-related injury. 1538 male army recruits were randomly 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. 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. A typical muscle stretching protocol performed during preexercise warm-ups does not produce clinically meaningful reductions in risk of exercise-related injury in army recruits. Fitness may be an important, modifiable risk factor.
Article
One-hundred-and-two high-level players of the field-games soccer, Gaelic football and hurling began a two-year investigation into the intrinsic causes of sports-injuries; 86 completed the study. During the first year all injuries, and the time affected by injury, were recorded. The subjects then underwent flexibility tests, an accurate photogrammetric assessment of posture, measures of speed and acceleration, and a clinical assessment of anatomical and physiological factors thought to be associated with the risk of sports injury. Time affected by injury was then recorded for a further 12-month period. Stepwise multiple-regression analysis revealed that the number of days of injury during the second 12-month period could be predicted from (1) the days of injury during the first 12-month period, (2) posture, (3) acceleration over 10m from a standing start, and (4) the number of musculo-skeletal clinical defects. Flexibility scores were not found to be significant predictors of injury. It is suggested that injury prevention programmes should concentrate on improving posture and the rehabilitation from previous injury rather than flexibility; and that research should be undertaken into the effectiveness of such interventions.
Article
The American Medical Association's (AMA) Guides to the Evaluation of Permanent Impairment range of motion-based (ROM) lumbar impairment model validity checks were reviewed. Published literature of lumbar ROM (LROM) testing also was reviewed for application of the AMA validity checking protocols. The utility and feasibility of use of the AMA Guides' ROM lumbar impairment ratings were examined. Although they appear to be essential components of the ROM model, few published studies report use of these validity checks. Of at least 22 reviewed studies of LROM testing, only six studies included at least three measurements (the bare minimum) of LROM. Furthermore, only two (9.1%) reported performance of the LROM validity check. Only one, however, reported the results. English language journals were searched on Medline using "region, lumbar," "range of motion," "validity of results," "observer variation," and "low back pain" as title and subject search terms. The study methodologies approximating the AMA Guides' specifications were included in the analysis. Under normal conditions of ROM measurement, 33% of three consecutive lumbar flexion and 27% of three consecutive lumbar extension measurements failed the LROM validity check. In addition, across three different experimental sessions (each with more than three consecutive LROM measurements taken) only 15 participants (33%) had valid flexion scores and only 24 participants (53%) had valid extension scores across all three sessions. Technical complications inherent in the ROM-based impairment-rating model render the validity checks difficult to perform satisfactorily and thus rarely used.
Article
The purpose of this study was to determine whether a flexibility training program, a weight training program, and the combination of both would affect running speed when used as supplementary training programs to the conventional method of training sprinters. One hundred and forty-five subjects, randomly assigned to one of five training groups, were tested for flexibility, leg strength, and running speed before and after an 8-week training period. Results showed that both weight training and flexibility training, as supplements to sprint training, increased running speed significantly more than an unsupplemented sprint training program.
Article
The effect of 3 warm-up routines on standing broad jump (SBJ) performance was investigated. Thirty-two men and women participated as subjects. Following the determination of 1-repetition maximum (1RM) squat, subjects completed warm-up routines and broad jumps on 4 occasions in a randomized order. Subjects performed SBJ immediately (POST) and 15 min following (POST15) the given warm-up routine. The routines were high force, consisting of high % 1RM, low repetition squats; high power, consisting of low % 1RM, low repetition speed squats; stretching, consisting of static stretches; and no activity, a control condition. Repeated measures analysis of covariance (ANCOVA) revealed no differences among broad jump performance following any of the warm-up routines (p = 0.157). A strong correlation (R = 0.805) was found between 1RM squat and SBJ. These data indicate that warm-up of any type has little effect on jump performance and that maximum strength is strongly related to jumping ability.
Article
We conducted a systematic review to assess the evidence for the effectiveness of stretching as a tool to prevent injuries in sports and to make recommendations for research and prevention. Without language limitations, we searched electronic data bases, including MEDLINE (1966-2002), Current Contents (1997-2002), Biomedical Collection (1993-1999), the Cochrane Library, and SPORTDiscus, and then identified citations from papers retrieved and contacted experts in the field. Meta-analysis was limited to randomized trials or cohort studies for interventions that included stretching. Studies were excluded that lacked controls, in which stretching could not be assessed independently, or where studies did not include subjects in sporting or fitness activities. All articles were screened initially by one author. Six of 361 identified articles compared stretching with other methods to prevent injury. Data were abstracted by one author and then reviewed independently by three others. Data quality was assessed independently by three authors using a previously standardized instrument, and reviewers met to reconcile substantive differences in interpretation. We calculated weighted pooled odds ratios based on an intention-to-treat analysis as well as subgroup analyses by quality score and study design. Stretching was not significantly associated with a reduction in total injuries (OR = 0.93, CI 0.78-1.11) and similar findings were seen in the subgroup analyses. There is not sufficient evidence to endorse or discontinue routine stretching before or after exercise to prevent injury among competitive or recreational athletes. Further research, especially well-conducted randomized controlled trials, is urgently needed to determine the proper role of stretching in sports.