להלן מחקר בנושא מתיחות לפני/אחרי אימון

[bigbit]

פורסם במקור על ידי shikoLM

אני מצרף לסקירה שמשה פרסם עוד סקירה גדולה של מחקרים שפורסמה ב Medicine & Science in Sports & Exercise בקשר לתועלת שבמתיחות. בקשר לשני המחקרים שאתה מדבר עליהם אין לי שום דרך להגיב עליהם שכן אני לא נתקלתי בהם אבל אם הם לא נכללו בסקירה של ז'ורנל כזה כנראה יש לך כך סיבה מספיק טובה (ממתודולוגיה שגויה, סטטיסטיקה בעייתית וכו').

The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature.
CLINICAL SCIENCES
Medicine & Science in Sports & Exercise. 36(3):371-378, March 2004.
THACKER, STEPHEN B. 1; GILCHRIST, JULIE 2; STROUP, DONNA F. 3; KIMSEY, C. DEXTER JR. 3
Abstract:
THACKER, S. B., J. GILCHRIST, D. F. STROUP, and C. D. KIMSEY, JR. The Impact of Stretching on Sports Injury Risk: A Systematic Review of the Literature. Med. Sci. Sports Exerc., Vol. 36, No. 3, pp. 371-378, 2004.
Purpose: 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.
Methods: 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.
Results: 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.
Conclusion: 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.
(C)2004The American College of Sports Medicine

תשמע המחקרים שאתה מביא מוכיחים שגמישות לא תעזור במקרה של מניעת doms או מניעת פציעות
בזה אני 100 אחוז מסכים איתך
אבל המתיחות כן יכולות לעזור בכמה דברים שוורטקס העלה כמו זרימת דם טובה יותר..פעילות טובה יותר של מערכת העצבים..הכנה פסיכולוגית להרמת משקולות..שיפור טווחי תנועה..שחרור האנטגוניסט שיתנגד פחות לאגוניסט בתנועה
על זה אני מדבר..

[shikoLM]

פורסם במקור על ידי bigbit

תשמע המחקרים שאתה מביא מוכיחים שגמישות לא תעזור במקרה של מניעת doms או מניעת פציעות
בזה אני 100 אחוז מסכים איתך
אבל המתיחות כן יכולות לעזור בכמה דברים שוורטקס העלה כמו זרימת דם טובה יותר..פעילות טובה יותר של מערכת העצבים..הכנה פסיכולוגית להרמת משקולות..שיפור טווחי תנועה..שחרור האנטגוניסט שיתנגד פחות לאגוניסט בתנועה
על זה אני מדבר..

הדבר היחיד שאני מסכים איתך עליו הוא הפן הפסיכולוגי, השיפור אם קיים הוא מהפן הזה. בקשר לשאר הדברים שציינת על הנייר זה נשמע טוב (זרימת דם טובה יותר, שיפור טווח תנועה וכו') השאלה היא אם יש לזה רלוונטיות מהבחינה המחקרית, משמע האם ביצוע מתיחות משפר ביצועים. מבחינה מחקרית עד עתה ראיתי כמה מחקרים בנושא שמצאו שמתיחות לא רק שלא משפרות ביצועים אלא גם שבמקרים מסויימים המשתתפים הראו יכולת נמוכה יותר.

Effect of acute static stretching on force, balance, reaction time, and movement time.

Behm DG, Bambury A, Cahill F, Power K.
School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Canada. dbehm@mun.ca
PURPOSE: The purpose of the study was to investigate the effect of an acute bout of lower limb static stretching on balance, proprioception, reaction, and movement time. METHODS: Sixteen subjects were tested before and after both a static stretching of the quadriceps, hamstrings, and plantar flexors or a similar duration control condition. The stretching protocol involved a 5-min cycle warm-up followed by three stretches to the point of discomfort of 45 s each with 15-s rest periods for each muscle group. Measurements included maximal voluntary isometric contraction (MVC) force of the leg extensors, static balance using a computerized wobble board, reaction and movement time of the dominant lower limb, and the ability to match 30% and 50% MVC forces with and without visual feedback. RESULTS: There were no significant differences in the decrease in MVC between the stretch and control conditions or in the ability to match submaximal forces. However, there was a significant (P < 0.009) decrease in balance scores with the stretch (decreasing 9.2%) compared with the control (increasing 17.3%) condition. Similarly, decreases in reaction (5.8%) and movement (5.7%) time with the control condition differed significantly (P < 0.01) from the stretch-induced increases of 4.0% and 1.9%, respectively. CONCLUSION: In conclusion, it appears that an acute bout of stretching impaired the warm-up effect achieved under control conditions with balance and reaction/movement time.
PMID: 15292749 [PubMed - indexed for MEDLINE]

Effects of static stretching volume and intensity on plantar flexor explosive force production and range of motion.

Young W, Elias G, Power J.
School of Human Movement and Sport Sciences, University of Ballarat, Ballarat, Victoria, Australia. w.young@ballarat.edu.au
AIM: The aim of the study was to determine the effects of volume and intensity of static stretching in a warm-up on explosive force production and range of motion (ROM) of the plantar flexors. METHODS: Twenty subjects performed 5 warm-ups on different days. The warm-ups contained a 5 min treadmill run and various protocols of 30 s static stretches (SS) of the plantar flexors. Stretching involved dorsi flexion just before the pain threshold, which was considered 100% intensity. The treatments that immediately followed the run were: (i) no other treatment (control); (ii) 1 min SS; (iii) 2 min SS; (iv) 4 min SS; (v) 2 min SS at 90% intensity. Ankle ROM was assessed before and after each warm-up and a concentric calf raise and drop jump (DJ) test was conducted after each warm-up. RESULTS: There were no significant differences (P > 0.05) in peak force or rate of force production in the explosive calf raise between any of the warm-ups. However the run plus 2 min stretch and the run plus 4 min stretch protocols produced significantly lower (P < 0.05) DJ performance (jump height/ground contact time) than the run. The run plus 4 min stretch warm-up also produced a significantly lower DJ score than the run plus 1 min stretch warm-up. There were no significant differences between any of the warm-ups in ankle ROM. CONCLUSIONS: The addition of 2-4 min of SS at 100% intensity to a run caused an impairment to fast stretch shortening cycle muscle performance. The greater impairment from the 4 min stretching condition supported a volume-effect. Two minutes of stretching at 90% intensity had no significant influence on muscle function. The addition of up to 4 min of SS to a run had no appreciable effect on ankle ROM, possibly because of the prior influence of the run.
PMID: 16998444 [PubMed - indexed for MEDLINE]



The effects of acute static stretching on reaction time and force.

Alpkaya U, Koceja D.
Department of Physical Education and Sports School of Health Physical Education and Sports Marmara University, Istanbul, Turkey.
AIM: The purpose of this study was to determine alterations in explosive force production and reaction time following the soleus and gastrocnemius muscle stretching. Specifically we investigated whether or not actually stretching the calf muscles would alter the performance of reaction time and force production. METHODS: Fifteen subjects (age: 25.07+/-5.35 years; height: 1.76+/-0.07 m; weight: 81.38+/-17.28 kg) completed 2 test sessions. All subjects underwent a warm-up of 5 min bicycling and stretching of the ankle plantar flexors followed by reaction time and force tasks, and a similar control period of no stretch of the ankle plantar flexors. Measure of reaction time and force were assessed following stretching and no stretching conditions. RESULTS: There were no significant differences in reaction time and force between the stretching and control conditions (P>0.05). CONCLUSION: These results demonstrated that 3 sets of 15 s duration of the static stretching did not have a positive or negative effect on reaction time and explosive force.
PMID: 17557051 [PubMed - indexed for MEDLINE]



Effects of six warm-up protocols on sprint and jump performance.

Vetter RE.
Health, Physical Education, Recreation, and Dance Department, Northwest Missouri State University, Maryville, Missouri 64468, USA. rvetter@nwmissouri.edu
The purpose of this study was to compare the effects of 6 warm-up protocols, with and without stretches, on 2 different power maneuvers: a 30-m sprint run and a vertical countermovement jump (CJ). The 6 protocols were: (a) walk plus run (WR); (b) WR plus exercises including small jumps (EJ); (c) WR plus dynamic active stretch plus exercises with small jumps (DAEJ); (d) WR plus dynamic active stretch (DA); (e) WR plus static stretch plus exercises with small jumps (SSEJ); and (f) WR plus static stretch (SS). Twenty-six college-age men (n = 14) and women (n = 12) performed each of 6 randomly ordered exercise routines prior to randomly ordered sprint and vertical jump field tests; each routine and subsequent tests were performed on separate days. A 2 x 6 repeated measures analysis of variance revealed a significant overall linear trend (p < or = 0.05) with a general tendency toward reduction in jump height when examined in the following analysis entry order: WR, EJ, DAEJ, DA, SSEJ, and SS. The post hoc analysis pairwise comparisons showed the WR protocol produced higher jumps than did SS (p = 0.003 < or = 0.05), and DAEJ produced higher jumps than did SS (p = 0.009 < or = 0.05). There were no significant differences among the 6 protocols on sprint run performance (p > or = 0.05). No significant interaction occurred between gender and protocol. There were significant differences between men and women on CJ and sprint trials; as expected, in general men ran faster and jumped higher than the women did. The data indicate that a warm-up including static stretching may negatively impact jump performance, but not sprint time.
PMID: 17685698 [PubMed - in process]



Acute effects of passive muscle stretching on sprint performance.

Nelson AG, Driscoll NM, Landin DK, Young MA, Schexnayder IC.
Department of Kinesiology, Louisiana State University, Baton Rouge, LA 70803, USA. anelso@lsu.edu
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.
PMID: 16194993 [PubMed - indexed for MEDLINE]

Acute effects of stretching on the neuromechanical properties of the triceps surae muscle complex.

Cornwell A, Nelson AG, Sidaway B.
Department of Kinesiology and Physical Education, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032, USA. acornwe@calstatela.edu
Previous research has shown that an acute bout of passive muscle stretching can diminish performance in certain movements where success is a function of maximal force and/or power output. Two possible mechanisms that might account for such findings are a change in active musculotendinous stiffness and a depression of muscle activation. To investigate the likelihood of these two mechanisms contributing to a post-stretch reduction in performance, we examined the acute effects of stretching on the active stiffness and muscle activation of the triceps surae muscle group during maximal single-joint jumps with movement restricted to the ankle joint. Ten males performed both static (SJ) and countermovement (CMJ) jumps before and after passively stretching the triceps surae. Electrical activity of the triceps surae during each jump was determined by integrating electromyographic recordings (IEMG) over the course of the movement. Triceps surae musculotendinous stiffness was calculated before and after stretching using a technique developed by Cavagna (1970). Following stretching, a significant decrease [mean (SD) 7.4 (1.9)%; P<0.05] in jump height for the CMJ occurred, but for the SJ, no significant ( P>0.05) change in jump height was found. A small but significant decrease [2.8 (1.24)%; P<0.05] in stiffness was noted, but the magnitude of this change was probably not sufficient for it to have been a major factor underlying the decline in CMJ performance. Paradoxically, after stretching, the SJ exhibited a significant ( P<0.05) decrease in IEMG, but the IEMG for the CMJ remained unchanged ( P>0.05). It appears that an acute bout of stretching can impact negatively upon the performance of a single-joint CMJ, but it is unlikely that the mechanism responsible is a depression of muscle activation or a change in musculotendinous stiffness.
PMID: 11882929 [PubMed - indexed for MEDLINE]



Acute effects of static stretching on maximal eccentric torque production in women.

Cramer JT, Housh TJ, Coburn JW, Beck TW, Johnson GO.
Department of Health and Exercise Science, University of Oklahoma, Norman, Oklahoma 73019, USA. jcramer@ou.edu
The purpose of this study was to examine the acute effects of static stretching on peak torque (PT) and the joint angle at PT during maximal, voluntary, eccentric isokinetic muscle actions of the leg extensors at 60 and 180 degrees x s(-1) for the stretched and unstretched limbs in women. Thirteen women (mean age +/- SD = 20.8 +/- 0.8 yr; weight +/- SD = 63.3 +/- 9.5 kg; height +/- SD = 165.9 +/- 7.9 cm) volunteered to perform separate maximal, voluntary, eccentric isokinetic muscle actions of the leg extensors with the dominant and nondominant limbs on a Cybex 6000 dynamometer at 60 and 180 degrees x s(-1). PT (Nm) and the joint angle at PT (degrees) were recorded by the dynamometer software. Following the initial isokinetic assessments, the dominant leg extensors were stretched (mean stretching time +/- SD = 21.2 +/- 2.0 minutes) using 1 unassisted and 3 assisted static stretching exercises. After the stretching (4.3 +/- 1.4 minutes), the isokinetic assessments were repeated. The statistical analyses indicated no changes (p > 0.05) from pre- to poststretching for PT or the joint angle at PT. These results indicated that static stretching did not affect PT or the joint angle at PT of the leg extensors during maximal, voluntary, eccentric isokinetic muscle actions at 60 and 180 degrees x s(-1) in the stretched or unstretched limbs in women. In conjunction with previous studies, these findings suggested that static stretching may affect torque production during concentric, but not eccentric, muscle actions.
PMID: 16686563 [PubMed - indexed for MEDLINE]

[shikoLM]

Acute effect of static stretching on power output during concentric dynamic constant external resistance leg extension.

Yamaguchi T, Ishii K, Yamanaka M, Yasuda K.
Laboratory of Human Performance and Fitness, Graduate School of Education, Hokkaido University, Sapporo, Japan. taichi@rakuno.ac.jp
The purpose of the present study was to clarify the effect of static stretching on muscular performance during concentric isotonic (dynamic constant external resistance [DCER]) muscle actions under various loads. Concentric DCER leg extension power outputs were assessed in 12 healthy male subjects after 2 types of pretreatment. The pretreatments included (a) static stretching treatment performing 6 types of static stretching on leg extensors (4 sets of 30 seconds each with 20-second rest periods; total duration 20 minutes) and (b) nonstretching treatment by resting for 20 minutes in a sitting position. Loads during assessment of the power output were set to 5, 30, and 60% of the maximum voluntary contractile (MVC) torque with isometric leg extension in each subject. The peak power output following the static stretching treatment was significantly (p < 0.05) lower than that following the nonstretching treatment under each load (5% MVC, 418.0 +/- 82.2 W vs. 466.2 +/- 89.5 W; 30% MVC, 506.4 +/- 82.8 W vs. 536.4 +/- 97.0 W; 60% MVC, 478.6 +/- 77.5 W vs. 523.8 +/- 97.8 W). The present study demonstrated that relatively extensive static stretching significantly reduces power output with concentric DCER muscle actions under various loads. Common power activities are carried out by DCER muscle actions under various loads. Therefore, the result of the present study suggests that relatively extensive static stretching decreases power performance.
PMID: 17194246 [PubMed - indexed for MEDLINE]



Duration of static stretching influences muscle force production in hamstring muscles.

Ogura Y, Miyahara Y, Naito H, Katamoto S, Aoki J.
Department of Exercise Physiology, School of Health and Sports Science, Juntendo University, Chiba, Japan. yuji-ogura@sakura.juntendo.ac.jp
The purpose of the present study was to investigate whether duration of static stretching could affect the maximal voluntary contraction (MVC).Volunteer male subjects (n = 10) underwent 2 different durations of static stretching of their hamstring muscles in the dominant leg: 30 and 60 seconds. No static stretching condition was used as a control condition. Before and after each stretching trial, hamstring flexibility was measured by a sit and reach test. MVC was then measured using the maximal effort of knee flexion. The hamstring flexibility was significantly increased by 30 and 60 seconds of static stretching (control: 0.5 +/- 1.1 cm; 30 seconds: 2.1 +/- 1.8 cm; 60 seconds: 3.0 +/- 1.6 cm); however, there was no significant difference between 30 and 60 seconds of static stretching conditions. The MVC was significantly lowered with 60 seconds of static stretching compared to the control and 30 seconds of the stretching conditions (control: 287.6 +/- 24.0 N; 30 seconds: 281.8 +/- 24.2 N; 60 seconds: 262.4 +/- 36.2 N). However, there was no significant difference between control and 30 seconds of static stretching conditions. Therefore, it was concluded that the short duration (30 seconds) of static stretching did not have a negative effect on the muscle force production.
PMID: 17685679 [PubMed - in process]

The effect of static, ballistic, and proprioceptive neuromuscular facilitation stretching on vertical jump performance.

Bradley PS, Olsen PD, Portas MD.
Sport and Exercise Group, University of Teesside, UK. paul.s.bradley@sunderland.ac.uk
The purpose of this study was to compare the acute effects of different modes of stretching on vertical jump performance. Eighteen male university students (age, 24.3 +/- 3.2 years; height, 181.5 +/- 11.4 cm; body mass, 78.1 +/- 6.4 kg; mean +/- SD) completed 4 different conditions in a randomized order, on different days, interspersed by a minimum of 72 hours of rest. Each session consisted of a standard 5-minute cycle warm-up, accompanied by one of the subsequent conditions: (a) control, (b) 10-minute static stretching, (c) 10-minute ballistic stretching, or (d) 10-minute proprioceptive neuromuscular facilitation (PNF) stretching. The subjects performed 3 trials of static and countermovement jumps prior to stretching and poststretching at 5, 15, 30, 45, and 60 minutes. Vertical jump height decreased after static and PNF stretching (4.0% and 5.1%, p < 0.05) and there was a smaller decrease after ballistic stretching (2.7%, p > 0.05). However, jumping performance had fully recovered 15 minutes after all stretching conditions. In conclusion, vertical jump performance is diminished for 15 minutes if performed after static or PNF stretching, whereas ballistic stretching has little effect on jumping performance. Consequently, PNF or static stretching should not be performed immediately prior to an explosive athletic movement.
PMID: 17313299 [PubMed - indexed for MEDLINE]

An acute bout of static stretching: effects on force and jumping performance.

Power K, Behm D, Cahill F, Carroll M, Young W.
School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Canada.
INTRODUCTION/PURPOSE: The objectives of this study were to examine whether a static stretching (SS) routine decreased isometric force, muscle activation, and jump power while improving range of motion (ROM). Second, the study attempted to compare the duration of the dependent variable changes with the duration of the change in ROM. METHODS: Twelve participants were tested pre- and post- (POST, 30, 60, 90, and 120 min) SS of the quadriceps and plantar flexors (PF) or a similar period of no stretch (control). Measurements during isometric contractions included maximal voluntary force (MVC), evoked contractile properties (peak twitch and tetanus), surface integrated electromyographic (iEMG) activity of the agonist and antagonistic muscle groups, and muscle inactivation as measured by the interpolated twitch technique (ITT). Vertical jump (VJ) measurements included unilateral concentric-only (no countermovement) jump height as well as drop jump height and contact time. ROM associated with seated hip flexion, prone hip extension, and plantar flexion-dorsiflexion was also recorded. RESULTS: After SS, there were significant overall 9.5% and 5.4% decrements in the torque or force of the quadriceps for MVC and ITT, respectively. Force remained significantly decreased for 120 min (10.4%), paralleling significant percentage increases (6%) in sit and reach ROM (120 min). After SS, there were no significant changes in jump performance or PF measures. CONCLUSION: The parallel duration of changes in ROM and quadriceps isometric force might suggest an association between stretch-induced changes in muscle compliance and isometric force output.
PMID: 15292748 [PubMed - indexed for MEDLINE]