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Jason Brandenburg, William A. Pitney, Paul E. Luebbers, Arun Veera and Alicja Czajka

Purpose:

To examine the acute effects of static stretching on countermovement vertical-jump (CMVJ) ability and monitor the time course of any stretch-induced changes.

Methods:

Once familiarized, 16 experienced jumpers completed 2 testing sessions in a randomized order. Each session consisted of a general warm-up, a pretreatment CMVJ assessment, a treatment, and multiple posttreatment CMVJ assessments. One treatment included lower-body static stretching, and the second treatment, involving no stretching, was the control. Posttreatment CMVJ measures occurred immediately, 3, 6, 12, and 24 minutes posttreatment. Stretching consisted of 3 static-stretching exercises, with each exercise repeated 3 times and each repetition held for 30 s.

Results:

Prestretch CMVJ height equaled 47.1 (± 9.7) cm. CMVJ height immediately poststretch was 45.7 (± 9.2) cm, and it remained depressed during the 24-min follow-up period. Pre-no-stretch CMVJ height was 48.4 (± 9.8) cm, whereas immediately post-no-stretch CMVJ height equaled 46.8 (± 9.5) cm, and as in the stretch treatment, post-no-stretch CMVJ height remained lower than pre-no-stretch values. Although there was a significant main effect of time (P = .005), indicating that CMVJ was lower and remained impaired after both treatments, no significant interaction effect (P = .749) was observed.

Conclusion:

In comparison with the no-activity control, static stretching resulted in similar reductions in CMVJ ability when examined over the same time course, so athletes preparing for CMVJ should avoid periods of inactivity, as well as static stretching.

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Philip Ford and John McChesney

Context:

Literature supports habitual stretching for increasing an individual’s flexibility; however, immediate gains in range of motion have received limited investigation.

Objective:

The purpose of this study was to determine the retention of active knee extension range of motion (AKE ROM) after a single bout of stretching.

Design:

Subjects participated in three experimental stretching groups: contract-relax, agonist contract (CRAC); static stretch; and active control stretch. AKE ROM was measured by an analog inclinometer fixed to a modified Orthotron II for pretreatment and posttreatment measurements at 0, 3, 7, 12, 18, and 25 minutes.

Participants:

32 active male and female college age students.

Results:

Analysis suggested that stretching as a combined treatment effect demonstrated an increase in AKE ROM that lasted for 25 minutes; however, no specific method of stretching was found to be more beneficial.

Conclusion:

Stretching utilizing CRAC, static, or active control techniques lend support to their use for the purpose of increasing and retaining ROM prior to physical activity.

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Theophanis Siatras, Georgios Papadopoulos, Dimitra Mameletzi, Vasilios Gerodimos and Spiros Kellis

Although warm-up and stretching exercises are routinely performed by gymnasts, it is suggested that stretching immediately prior to an activity might affect negatively the athletic performance. The focus of this investigation was on the acute effect of a protocol, including warm-up and static and dynamic stretching exercises, on speed during vaulting in gymnastics. Eleven boys were asked to perform three different protocols consisting of warm-up, warm-up and static stretching and warm-up and dynamic stretching, on three nonconsecutive days. Each protocol was followed by a “handspring” vault. One-way analysis of variance for repeated-measures showed a significant difference in gymnasts’ speed, following the different protocols. Tukey’s post hoc analysis revealed that gymnasts mean speed during the run of vault was significantly decreased after the application of the static stretching protocol. The findings of the present study indicate the inhibitory role of an acute static stretching in running speed in young gymnasts.

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Jacob Buus Andersen and Thomas Sinkjaer

Due to the complexity of applying a well-defined stretch during human walking, most of our knowledge about the short latency stretch reflex modulation in humans is based on H-reflex studies. To illuminate the difference between the two methodologies, both types of reflexes were evoked in the same subjects, same experiment. Stretch reflexes were evoked via a stretch device capable of evoking stretch reflexes of the human soleus muscle during walking. H-reflexes were elicited by an electrical stimulation of the tibial nerve at the popliteal fossa at the knee. A significantly different modulation of the two reflexes was found in the late stance where the stretch reflex decreased in relation to the H-reflex. This was consistent with an unloading of the muscle spindles during the push-off in late stance, suggesting a complex alpha-gamma coactivation, if any, at this time of the step. The soleus stretch reflex and H-reflex were compared during the stance phase of walking and sitting at matched soleus EMG activity. No difference was found in the amplitude of the stretch reflex. However, there was a significant decrease of the H-reflex during the stance phase of walking, consistent with a task-specific presynaptic mediated reflex control. It is proposed that the short latency stretch reflex during walking is not sensitive to such a presynaptic inhibition.

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Athanasios Zakas, George Doganis, Christos Galazoulas and Efstratios Vamvakoudis

Although athletes routinely perform warm-up and stretching exercises, it has been suggested that prolonged stretching immediately before an activity might negatively affect the force production. Sixteen male pubescent soccer players participated in the study to examine whether a routine duration of acute static stretching is responsible for losses in isokinetic peak torque production. All participants performed two static stretching protocols in nonconsecutive training sessions. The first stretching protocol was performed three times for 15 s (volume 45) and the second 20 times for 15 s (volume 300). Range of motion (ROM) was determined during knee flexion with the use of a goniometer. The peak torque of the dominant leg extensors was measured on a Cybex NORM dynamometer at various angular velocities. The statistical analysis showed that peak torque did not change following the static stretching for 45 s in all angular velocities, while it decreased (p < .001) in all angular velocities following the static stretching for 5 min. The findings suggest that strength decreases after static stretching exercises may be the result of the performed stretching duration.

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Hsuan Su, Nai-Jen Chang, Wen-Lan Wu, Lan-Yuen Guo and I-Hua Chu

Context:

Foam rolling has been proposed to improve muscle function, performance, and joint range of motion (ROM). However, whether a foam rolling protocol can be adopted as a warm-up to improve flexibility and muscle strength is unclear.

Objectives:

To examine and compare the acute effects of foam rolling, static stretching, and dynamic stretching used as part of a warm-up on flexibility and muscle strength of knee flexion and extension.

Design:

Crossover study.

Setting:

University research laboratory.

Participants:

15 male and 15 female college students (age 21.43 ± 1.48 y, weight 65.13 ± 12.29 kg, height 166.90 ± 6.99 cm).

Main Outcome Measures:

Isokinetic peak torque was measured during knee extension and flexion at an angular velocity of 60°/second. Flexibility of the quadriceps was assessed by the modified Thomas test, while flexibility of the hamstrings was assessed using the sit-and-reach test. The 3 interventions were performed by all participants in random order on 3 days separated by 48–72 hours.

Results:

The flexibility test scores improved significantly more after foam rolling as compared with static and dynamic stretching. With regard to muscle strength, only knee extension peak torque (pre vs. postintervention) improved significantly after the dynamic stretching and foam rolling, but not after static stretching. Knee flexion peak torque remained unchanged.

Conclusions:

Foam rolling is more effective than static and dynamic stretching in acutely increasing flexibility of the quadriceps and hamstrings without hampering muscle strength, and may be recommended as part of a warm-up in healthy young adults.

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Che-Hsiu Chen, Trevor C. Chen, Mei-Hwa Jan and Jiu-Jenq Lin

Objectives:

To examine whether an acute bout of active or dynamic hamstring-stretching exercises would reduce the amount of muscle damage observed after a strenuous eccentric task and to determine whether the stretching protocols elicit similar responses.

Design:

A randomized controlled clinical trial.

Methods:

Thirty-six young male students performed 5 min of jogging as a warm-up and were allocated to 1 of 3 groups: 3 min of static active stretching (SAS), 3 min of dynamic active stretching (DAS), or control (CON). All subjects performed eccentric exercise immediately after stretching. Heart rate, core temperature, maximal voluntary isometric contraction, passive hip flexion, passive hamstring stiffness (PHS), plasma creatine kinase activity, and myoglobin were recorded at prestretching, at poststretching, and every day after the eccentric exercises for 5 d.

Results:

After stretching, the change in hip flexion was significantly higher in the SAS (5°) and DAS (10.8°) groups than in the CON (–4.1°) group. The change in PHS was significantly higher in the DAS (5.6%) group than in the CON (–5.7%) and SAS (–6.7%) groups. Furthermore, changes in muscle-damage markers were smaller in the SAS group than in the DAS and CON groups.

Conclusions:

Prior active stretching could be useful for attenuating the symptoms of muscle damage after eccentric exercise. SAS is recommended over DAS as a stretching protocol in terms of strength, hamstring range of motion, and damage markers.

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Nicolas Babault, Wacef Bazine, Gaëlle Deley, Christos Paizis and Grégory Lattier

Purpose:

To examine the acute effect of a single static-stretching session of hamstring muscles on torque production in relation with individual flexibility.

Methods:

Maximal voluntary concentric torque of hamstring muscles was measured before and after a static-stretching session (6 × 30 s). Torque changes were correlated with the flexibility level determined at the onset of the experimental procedure.

Results:

The hamstring-stretching intervention significantly reduced maximal concentric torque in participants with low and high hamstring flexibility. Hamstring flexibility and torque decrease, determined immediately after the stretching procedure, were negatively correlated.

Conclusions:

Torque decrease measured after the static-stretching session is dependent on participant flexibility. Participants with low flexibility are much more likely to demonstrate large torque decreases poststretching.

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Wolfgang Seiberl, Daniel Hahn, Florian Kreuzpointner, Ansgar Schwirtz and Uwe Gastmann

The purpose of this study was to investigate if force enhancement (FE) in vivo is influenced by stretch-induced changes of muscle architecture. Therefore, 18 subjects performed maximum voluntary isometric (100° knee flexion angle) and isometric-eccentric-isometric stretch contractions (80°–100° ω = 60°s−1) whereby pennation angle and fascicle length of vastus lateralis was determined using ultrasonography. We found significant (2-way repeated ANOVA; α = 0.05) enhanced torque of 5–10% after stretch as well as significant passive FE but no significant differences in muscle architecture between isometric and stretch contractions at final knee angle. Furthermore, EMG recordings during a follow-up study (n = 10) did not show significant differences in activation and mean frequency of contraction conditions. These results indicate that FE in vivo is not influenced by muscle architectural changes due to stretch.

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Eric Sauers, Anna August and Alison Snyder

Context:

Stretching prior to activity or as a rehabilitative intervention may promote increased throwing shoulder range of motion (ROM) in baseball pitchers.

Objective:

To evaluate the acute effects of Fauls modified passive stretching routine on throwing shoulder mobility in collegiate baseball players.

Design:

Repeated measures.

Setting:

Laboratory.

Participants:

Thirty collegiate baseball players with unimpaired shoulders.

Interventions:

Fauls modified passive stretching routine was performed on the throwing shoulder of each subject.

Outcome Measures:

Shoulder complex and passive isolated glenohumeral internal and external rotation ROM were measured with a goniometer, and posterior shoulder tightness was assessed with the Tyler’s test method using a carpenter’s square. Measurements were made bilaterally.

Results:

The dominant shoulder displayed significant increases in glenohumeral and shoulder complex internal and external rotation ROM and significantly decreased posterior shoulder tightness following the stretching routine.

Conclusion:

Application of the Fauls modified passive shoulder stretching routine results in acute gains in throwing shoulder mobility of collegiate baseball players.