A review of the acute effects of static and dynamic stretching on performance

Acute response on general and sport specific hip joint flexibility to training with novel sport device

The study objective is to test general- and sport-specific adaption during a single training on the Flexibility Trainer. The device is designed to trigger residual muscle tone decreases of the hip-joint muscles by providing (nearly) isokinetic resistance during a full range of motion strength training in adduction/abduction and flexion/extension direction. Static hip flexion and abduction as well as kinematics of double side kicks were analysed on 15 participants before and after training (or rest for controls) to assess general flexibility and sport-specific movement range. Tests were recorded by a Vicon® motion capturing system. Static hip flexion and abduction as well as leg vector spreading angles (VSA) at different nodes of the kick were selected to determine adaptions of active and passive flexibility. Normalised hip joint moments, movement velocities and VSA were calculated to evaluate the training with the device. ANOVAs with 4-repeated measures and Friedman tests were performed to identify time differences and Bonferroni post-hoc test to identify between-subject effects. Significant differences were found for both static flexibility tests (Flexion = 13.65%; Abduction = 9.94%) and the VSA at specific action phases (≤15.15%). Results indicate that short-term adaptions when training with the Flexibility Trainer are exceeding comparable literature showing improved flexibility and sport-specific performance.

Effects of slow dynamic, fast dynamic, and static stretching on recovery of performance, range of motion, balance, and joint position sense in healthy adults

INTRODUCTION

Considering the effects of fatigue on athletic performance and the subsequent increase in the probability of injury, the purpose of this study was to compare the effects of slow dynamic, fast dynamic, and static stretching on the recovery of performance, range of motion (ROM), balance, and joint position sense.

METHODS

Fifteen collegiate healthy females were involved in four separate sessions of slow dynamic stretching (SDS), fast dynamic stretching (FDS), static stretching (SS), and control condition (CC; without stretching), in a random order with at least 48 h of rest between sessions. After warming up, the individuals performed ROM, balance, joint position sense (JPS) maximum voluntary isometric contraction (MVIC) force as well as countermovement (CMJ) and squat jump (SJ) as pre-tests. After performing the knee fatigue protocol of 4 sets of knee extension and flexion at 60% of 1 repetition maximum (RM) to exhaustion (CC; without stretching) or stretching programs (SDS or FDS or SS), the subjects repeated all the tests at post-test 1 (after 5 min) and post-test 2 (after 60 min).

RESULTS

A significantly lower JPS error was detected with SDS while JPS error increased in the SS and control conditions (p < 0.0001). MVIC force significantly increased with SDS and FDS but decreased in control and SS conditions (p < 0.0001). Moreover, a significant decrease in CMJ and SJ height in SS and control conditions was revealed (p < 0.0001). Also, a significant decrease in balance with the control condition was revealed. But only SDS minimized fatigue-induced balance decrements (p < 0.0001). Additionally, the control condition experienced a significant decrease in knee extensor ROM, which contrasted with the significant increase in the quadriceps flexibility with the stretching conditions.

CONCLUSIONS

The present results support the idea that SDS may increase quadriceps MVIC force, knee extensor ROM and knee JPS. So according to the present results, it is suggested that the SDS could be implemented and incorporated into a regular recovery program.

Acute effects of voluntary isometric contractions at maximal shortening vs. ballistic stretching on flexibility, strength and jump

Background

Isometric training is used in sport, conventional physical activity and rehabilitation. Understandably, there is a great deal of research related to its effect on performance. It is known that the length of the muscle at the moment of contraction is a determinant of strength levels. In the literature we find research on isometric training in short muscle lengths, although it has not been studied in maximally shortened positions or the acute effects that occur after its application. Ballistic stretching (BS) is also popular in sport. Their execution involves actively reaching maximally shortened muscle positions. So far, isometric training has not been compared with protocols involving ballistic stretching. Considering the above, the aim of the present study was to investigate the effects of BS and voluntary isometric contraction at maximal shortening (VICAMS) on range of motion, strength and vertical jump.

Methods

The study involved 60 healthy, physically active individuals (40 and 52 years old) who were randomly assigned to three groups: BS, VICAMS and a control group (CG). To assess acute effects, before and after the intervention, active range of motion (AROM), maximal voluntary isometric force (MVIF) and countermovement jump height (CMJ) were determined.

Results

Time main effects and time*group interactions were found for all variables (p < 0.001). Between-group differences were shown for the VICAMS group after the intervention, with statistically significant higher AROM values compared to the other groups. MVIF values were also higher in the VICAMS group. Intra-group differences were observed for the VICAMS and Ballistic groups, as values on all variables increased from baseline. For the CMJ, intra-group differences showed that both the VICAMS and BS groups improved values compared to baseline values.

Conclusions

The application of VICAMS induced acute improvements over BS in AROM, MVIF and CMJ. These results are important for coaches seeking immediate performance improvement and offer an optimal solution to the warm-up protocol.

Foam rolling and stretching do not provide superior acute flexibility and stiffness improvements compared to any other warm-up intervention: A systematic review with meta-analysis

BACKGROUND

Acute improvement in range of motion (ROM) is a widely reported effect of stretching and foam rolling, which is commonly explained by changes in pain threshold and/or musculotendinous stiffness. Interestingly, these effects were also reported in response to various other active and passive interventions that induce responses such as enhanced muscle temperature. Therefore, we hypothesized that acute ROM enhancements could be induced by a wide variety of interventions other than stretching or foam rolling that promote an increase in muscle temperature.

METHODS

After a systematic search in PubMed, Web of Science, and SPORTDiscus databases, 38 studies comparing the effects of stretching and foam rolling with several other interventions on ROM and passive properties were included. These studies had 1134 participants in total, and the data analysis resulted in 140 effect sizes (ESs). ES calculations were performed using robust variance estimation model with R-package.

RESULTS

Study quality of the included studies was classified as fair (PEDro score = 4.58) with low to moderate certainty of evidence. Results showed no significant differences in ROM (ES = 0.01, p = 0.88), stiffness (ES = 0.09, p = 0.67), or passive peak torque (ES = -0.30, p = 0.14) between stretching or foam rolling and the other identified activities. Funnel plots revealed no publication bias.

CONCLUSION

Based on current literature, our results challenge the established view on stretching and foam rolling as a recommended component of warm-up programs. The lack of significant difference between interventions suggests there is no need to emphasize stretching or foam rolling to induce acute ROM, passive peak torque increases, or stiffness reductions.

Acute Effects of Slow, Moderate and Fast Tempo Dynamic Stretching Exercises on Power in Well-Trained Male Wrestlers

Due to the potential detrimental effects of static stretching exercises on subsequent muscle power performance, athletes and trainers have started to replace static stretching with dynamic stretching exercises in their training routines. However, there are no well-accepted guidelines regarding dynamic stretching variables, including tempo/velocity, volume (reps and sets), etc. Therefore, this study aimed to evaluate the acute effects of slow, moderate, and fast tempo dynamic stretching exercises on jump height, relative power, the reactive strength index, and leg stiffness in well-trained male wrestlers. Seventeen wrestlers (aged 20.00 ± 4.06 years, wrestling experience 6.00 ± 3.09 years, and training volume per week 10.00 ± 5.69 hours) took part in the experiment under four conditions (control session, slow tempo dynamic stretching, moderate tempo dynamic stretching, and fast tempo dynamic stretching) on separate days with a 72-h interval in between, following a randomized, crossover study design. The control session consisted of a 10-min jog on a motor-driven treadmill at 6 km/h and a 0% slope. Dynamic stretching sessions consisted of seven dynamic stretching exercises performed at 50 bpm, 100 bpm, and 120 bpm, following a 5-min warm-up on a treadmill at 6 km/h and a 0% slope. After each condition, wrestlers performed a 2 x 30-s repeated vertical jump test with 5-min rest intervals in between. The best results for jump height, relative power, the reactive strength index, and leg stiffness were registered for statistical analysis. One-way repeated ANOVA results demonstrated that there were no significant differences in pairwise comparisons of all variables obtained after the four different conditions (p > 0.05). Overall, none of the slow, moderate, and fast tempo dynamic stretching exercises led to a change in repeated jump performance of well-trained male athletes. Further studies are needed to clarify the acute effects of different tempo dynamic stretching on muscular performance in well-trained wrestlers.

Discussing Conflicting Explanatory Approaches in Flexibility Training Under Consideration of Physiology: A Narrative Review

The mechanisms underlying range of motion enhancements via flexibility training discussed in the literature show high heterogeneity in research methodology and study findings. In addition, scientific conclusions are mostly based on functional observations while studies considering the underlying physiology are less common. However, understanding the underlying mechanisms that contribute to an improved range of motion through stretching is crucial for conducting comparable studies with sound designs, optimising training routines and accurately interpreting resulting outcomes. While there seems to be no evidence to attribute acute range of motion increases as well as changes in muscle and tendon stiffness and pain perception specifically to stretching or foam rolling, the role of general warm-up effects is discussed in this paper. Additionally, the role of mechanical tension applied to greater muscle lengths for range of motion improvement will be discussed. Thus, it is suggested that physical training stressors can be seen as external stimuli that control gene expression via the targeted stimulation of transcription factors, leading to structural adaptations due to enhanced protein synthesis. Hence, the possible role of serial sarcomerogenesis in altering pain perception, reducing muscle stiffness and passive torque, or changes in the optimal joint angle for force development is considered as well as alternative interventions with a potential impact on anabolic pathways. As there are limited possibilities to directly measure serial sarcomere number, longitudinal muscle hypertrophy remains without direct evidence. The available literature does not demonstrate the necessity of only using specific flexibility training routines such as stretching to enhance acute or chronic range of motion.

Effects of Stretching or Strengthening Exercise on Spinal and Lumbopelvic Posture: A Systematic Review with Meta-Analysis

BACKGROUND

Abnormal posture (e.g. loss of lordosis) has been associated with the occurrence of musculoskeletal pain. Stretching tight muscles while strengthening the antagonists represents the most common method to treat the assumed muscle imbalance. However, despite its high popularity, there is no quantitative synthesis of the available evidence examining the effectiveness of the stretch-and-strengthen approach.

METHODS

A systematic review with meta-analysis was conducted, searching PubMed, Web of Science and Google Scholar. We included controlled clinical trials investigating the effects of stretching or strengthening on spinal and lumbopelvic posture (e.g., pelvic tilt, lumbar lordosis, thoracic kyphosis, head tilt) in healthy individuals. Effect sizes were pooled using robust variance estimation. To rate the certainty about the evidence, the GRADE approach was applied.

RESULTS

A total of 23 studies with 969 participants were identified. Neither acute (d = 0.01, p = 0.97) nor chronic stretching (d=-0.19, p = 0.16) had an impact on posture. Chronic strengthening was associated with large improvements (d=-0.83, p = 0.01), but no study examined acute effects. Strengthening was superior (d = 0.81, p = 0.004) to stretching. Sub-analyses found strengthening to be effective in the thoracic and cervical spine (d=-1.04, p = 0.005) but not in the lumbar and lumbopelvic region (d=-0.23, p = 0.25). Stretching was ineffective in all locations (p > 0.05).

CONCLUSION

Moderate-certainty evidence does not support the use of stretching as a treatment of muscle imbalance. In contrast, therapists should focus on strengthening programs targeting weakened muscles.

Effect of Static Stretching on Tendon Hysteresis and Efficiency During Repetitive Jumping

ABSTRACT

Sasajima, S and Kubo, K. Effect of static stretching on tendon hysteresis and efficiency during repetitive jumping. J Strength Cond Res 38(6): 1041-1047, 2024-To date, no studies have experimentally shown a relationship between tendon hysteresis and exercise efficiency. However, previous studies showed that tendon hysteresis decreased immediately after static stretching. The purposes of this study were to (a) investigate the change in tendon hysteresis during the recovery period after static stretching and (b) determine whether exercise efficiency is enhanced because of the decline of tendon hysteresis after static stretching. For stretching (1 minute × 4 sets) and control conditions, tendon hysteresis was measured during ramp (i.e., lower strain rate of tendon) and ballistic (i.e., higher strain rate of tendon) contractions before, immediately, 15, 30, 45, and 60 minutes after interventions. In addition, electromyograms of the plantar flexor muscles (medial gastrocnemius [MG], lateral gastrocnemius [LG], and soleus muscles [SOL]) and oxygen consumption (V̇O 2 ) were measured during 10 minutes of submaximal repetitive jumping after both interventions. Tendon hysteresis (during ramp and ballistic contractions) reduced by static stretching persisted for up to 60 minutes (effect of time p < 0.001). During repetitive jumping, no differences in electromyograms of the plantar flexor muscles (effect of condition p = 0.786 for MG, p = 0.124 for LG, p = 0.682 for SOL) or V̇O 2 (effect of condition p = 0.534) were found between stretching and control conditions. These results suggest that the reduction in tendon hysteresis because of static stretching continues until 60 minutes after the end of stretching, and static stretching does not change the efficiency (evaluated by electromyograms of the plantar flexor muscles and V̇O 2 ) during submaximal repetitive jumping.

Resistance Training Causes the Stretch-Induced Force Deficit-A Randomized Cross-Over Study

PURPOSE

Stretch-induced force deficit suggests an acute stretch-specific strength capacity loss, which is commonly attributed to EMG reductions. Since those deficits could also be attributed to general fatigue induced by overloading the muscle, this study aimed to compare stretching with an exhausting calf raise programme to compare strength and stretching responses.

METHOD

This study included 16 participants with different, high-duration calf muscle stretching effects (10, 20, 30 min of stretching) with resistance training (RT) (3 × 12 repetitions) performed until muscle failure, by using a cross-over study design with pre-post comparisons. Strength was tested via isometric plantar flexor diagnostics, while flexibility was assessed using the knee-to-wall test (KtW) and an isolated goniometer test.

RESULTS

Using a three-way ANOVA, RT strength decreases were greater compared to 10 and 20 min of stretching (p = 0.01-0.02), but similar to those of 30 min of stretching. ROM in the KtW showed no specific stretch-induced increases, while only the stretching conditions enhanced isolated tested ROM (p < 0.001-0.008). No RT-related isolated ROM increases were observed.

CONCLUSIONS

The results showed both interventions had similar effects on strength and ROM in the calf muscles. More holistic explanatory approaches such as fatigue and warm-up are discussed in the manuscript and call for further research.

Revisiting the stretch-induced force deficit: A systematic review with multilevel meta-analysis of acute effects

BACKGROUND

When recommending avoidance of static stretching prior to athletic performance, authors and practitioners commonly refer to available systematic reviews. However, effect sizes (ES) in previous reviews were extracted in major part from studies lacking control conditions and/or pre-post testing designs. Also, currently available reviews conducted calculations without accounting for multiple study outcomes, with ES: -0.03 to 0.10, which would commonly be classified as trivial.

METHODS

Since new meta-analytical software and controlled research articles have appeared since 2013, we revisited the available literature and performed a multilevel meta-analysis using robust variance estimation of controlled pre-post trials to provide updated evidence. Furthermore, previous research described reduced electromyography activity-also attributable to fatiguing training routines-as being responsible for decreased subsequent performance. The second part of this study opposed stretching and alternative interventions sufficient to induce general fatigue to examine whether static stretching induces higher performance losses compared to other exercise routines.

RESULTS

Including 83 studies with more than 400 ES from 2012 participants, our results indicate a significant, small ES for a static stretch-induced maximal strength loss (ES = -0.21, p = 0.003), with high magnitude ES (ES = -0.84, p = 0.004) for stretching durations ≥60 s per bout when compared to passive controls. When opposed to active controls, the maximal strength loss ranges between ES: -0.17 to -0.28, p < 0.001 and 0.040 with mostly no to small heterogeneity. However, stretching did not negatively influence athletic performance in general (when compared to both passive and active controls); in fact, a positive effect on subsequent jumping performance (ES = 0.15, p = 0.006) was found in adults.

CONCLUSION

Regarding strength testing of isolated muscles (e.g., leg extensions or calf raises), our results confirm previous findings. Nevertheless, since no (or even positive) effects could be found for athletic performance, our results do not support previous recommendations to exclude static stretching from warm-up routines prior to, for example, jumping or sprinting.

Acute effect of static stretching and pilates stretching on the concentric muscle strength of the knee extensors and flexors

INTRODUCTION

The effects of stretching exercises on muscle strength have been widely researched in the literature, however, there are no studies investigating the effects of Pilates stretching.

OBJECTIVE

To compare the effects of static stretching and Pilates stretching on the concentric muscle strength of the knee extensors and flexors.

METHOD

102 trained young adults were randomized into three groups: static stretching (n = 33); Pilates stretching (n = 34); control (n = 35). Isokinetic evaluation of the knee extensor and flexor muscles was performed at 60°/s and 180°/s, pre and post acute intervention with stretching. Interventions in the static stretching and Pilates stretching groups occurred in 3 sets x 30 s for each body region considered (a-knee extensor muscles; b-knee flexor muscles). The control group did not perform any intervention.

RESULTS

No difference (p > 0.05) was observed between the groups after the intervention. There was only a significant intragroup improvement for the control group on the isokinetic muscle strength of the knee flexors at 180°/s, with a moderate effect size, considering the entire sample (p = 0.040; d = 0.42) and when considering only male gender (p = 0.010; d = 0.60).

CONCLUSION

Static stretching or Pilates stretching performed as a warm-up did not impair or enhance the concentric muscle strength performance of the knee extensors and flexors. In this way, both forms of stretching can be considered as preparatory exercises before muscle strength training.

Combined Effects of Static and Dynamic Stretching on the Muscle-Tendon Unit Stiffness and Strength of the Hamstrings

ABSTRACT

Takeuchi, K, Nakamura, M, Matsuo, S, Samukawa, M, Yamaguchi, T, and Mizuno, T. Combined effects of static and dynamic stretching on the muscle-tendon unit stiffness and strength of the hamstrings. J Strength Cond Res 38(4): 681-686, 2024-Combined static and dynamic stretching for 30 seconds is frequently used as a part of a warm-up program. However, a stretching method that can both decrease muscle-tendon unit (MTU) stiffness and increase muscle strength has not been developed. The purpose of this study was to examine the combined effects of 30 seconds of static stretching at different intensities (normal-intensity static stretching [NS] and high-intensity static [HS]) and dynamic stretching at different speeds (low-speed dynamic [LD] and high-speed dynamic stretching [HD]) on the MTU stiffness and muscle strength of the hamstrings. Thirteen healthy subjects (9 men and 4 women, 20.9 ± 0.8 years, 169.3 ± 7.2 cm, 61.1 ± 8.2 kg) performed 4 types of interventions (HS-HD, HS-LD, NS-HD, and NS-LD). Range of motion (ROM), passive torque, MTU stiffness, and muscle strength were measured before and immediately after interventions by using an isokinetic dynamometer machine. In all interventions, the ROM and passive torque significantly increased (p < 0.01). Muscle-tendon unit stiffness significantly decreased in HS-HD and HS-LD (both p < 0.01), but there was no significant change in NS-HD (p = 0.30) or NS-LD (p = 0.42). Muscle strength significantly increased after HS-HD (p = 0.02) and NS-LD (p = 0.03), but there was no significant change in HS-LD (p = 0.23) or NS-LD (p = 0.26). The results indicated that using a combination of 30 seconds of high-intensity static stretching and high-speed dynamic stretching can be beneficial for the MTU stiffness and muscle strength of the hamstrings.

The Effects of 5 Minutes of Static Stretching on Joint Flexibility and Muscle Strength Are Comparable Between Ballet Dancers and Non-Dancers

Introduction: Ballet dancers have a special morphology, such as a large muscle thickness that affects passive torque. Ballet dancers also possess specialized mechanical, and neural properties of muscles and tendons. These characteristics may produce different static stretching effects than non-dancers. Therefore, this study aimed to determine the differences in the effects of static stretching on joint range of motion, passive torque, and muscle strength between ballet dancers and non-dancers. Methods: This study included 13 ballet dancers and 13 college students. The muscle and tendon thicknesses were assessed using ultrasonography. In the right lower extremity, torque-angle data and muscle-tendon junction displacement measurements were obtained during isokinetic passive dorsiflexion before and after a 5-minute static stretch against the right plantar flexors. The relative stretching intensity was calculated by dividing the stretching angle by the maximal dorsiflexion angle pre-stretch. Additionally, the isometric maximal voluntary plantar flexion torque on the left ankle was measured before and after 5 minutes of static stretching against the left plantar flexors. Results: Ballet dancers had significantly greater muscle thickness than non-dancers (22.4 ± 2.2 vs 18.1 ± 1.7 mm), whereas no significant difference was observed in the Achilles tendon thickness. No significant difference was observed in the stretching angle; however, the relative stretching intensity was higher in the control group (65.9 ± 19.8 vs 127.5 ± 63.8%). Static stretching increased the maximal dorsiflexion angle (dancer: 30.4° ± 9.6° to 33.9° ± 9.5°, non-dancer: 18.4° ± 8.6° to 20.5° ± 9.5°) and maximal passive torque in both groups, whereas the maximal isometric plantar flexion torque and submaximal passive torque decreased. However, no significant differences were observed in the changes between the groups. Conclusion: These results indicate that despite having a lower relative stretching intensity, ballet dancers experienced similar changes as non-dancers after 5 minutes of static stretching.

Comparative Effectiveness of Active Recovery and Static Stretching During Post-Exercise Recovery in Elite Youth Basketball

Purpose: To compare the effectiveness of active recovery (AR) versus static stretching (SS) during post-exercise recovery in basketball. Methods: Using a counterbalanced crossover design, 17 elite youth male players completed two 90-min training sessions, followed by either AR or SS. Differences in jump height (CMJ), heart rate variability (Ln-rMSSD), muscle soreness (VAS), perceived recovery (TQR) and hormonal biomarkers (cortisol, testosterone, testosterone:cortisol ratio) between interventions were assessed at pre-session, post-session (except hormonal biomarkers), post-recovery and 24 h post-session. Differences in Ln-rMSSD were additionally assessed upon awakening on training day, and the following morning. Results: No significant differences were found between interventions at corresponding time points (p > .05). However, the within-intervention time course of recovery differed, as CMJ values were lower at post-recovery, compared with all other time points, in SS only (p < .05, effect size [ES] moderate-to-very large). Additionally, Ln-rMSSD values failed to return to baseline at post-recovery in AR only (p < .05, ES large-to-very large). Similarly, TQR scores were impaired at post-session and post-recovery in AR only (p < .05, ES moderate-to-large). No differences were reported for the remaining variables (p > .05). Conclusion: Differences between AR and SS were probably due to short-term phenomena, indicating that neither strategy was likely superior for improving recovery in the longer term. Overall, neither strategy seemed to significantly improve post-exercise recovery.

Examining the Influence of Warm-Up Static and Dynamic Stretching, as well as Post-Activation Potentiation Effects, on the Acute Enhancement of Gymnastic Performance: A Systematic Review with Meta-Analysis

The primary objective of this systematic review with meta-analysis is to methodically discern and compare the impact of diverse warm-up strategies, including both static and dynamic stretching, as well as post-activation potentiation techniques, on the immediate performance of gymnasts. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, this paper evaluated studies that examined the gymnasts' performance after different warm-up strategies namely stretching (static [SS] or dynamic), vibration platforms (VP) or post-activation, in comparison to control conditions (e.g., mixed warm-up routines; no warm-up). The principal outcomes were centered on technical performance metrics (e.g., split, gymnastic jumps) and physical performance metrics (e.g., squat jump, countermovement jump, drop jump, balance, range of motion). Methodological assessments of the included studies were conducted using the Downs and Black Checklist. From the initial search across PubMed, Scopus, and the Web of Science databases, a total of 591 titles were retrieved, and 19 articles were ultimately incorporated in the analysis. The results revealed a non-significant differences (p > 0.05) between the SS condition and control conditions in squat jump performance, countermovement jump and gymnastic technical performance (e.g., split; split jump). Despite the difference in warm-up strategies and outcomes analyzed, the results suggest that there is no significant impairment of lower-limb power after SS. Additionally, technical elements dependent on flexibility appear to be enhanced by SS. Conversely, dynamic stretching and VP seem to be more effective for augmenting power-related and dynamic performance in gymnasts.

Acute Effects of a Warm-Up Intervention on Pain, Productivity, Physical Capacities and Psychological Perceptions Among Vineyard Workers: a Cluster Randomized Trial

PURPOSE

Agriculture is one of the sectors that are the most concerned by musculoskeletal disorders (MSDs). Workplace physical activity programs are one of the most promising solutions to prevent adverse consequences of MSDs such as pain or impairment in physical capacities. The aims of this study were twofold: (1) to investigate the acute effect of a warm-up session on pain, work performance, physical capacities and psychosocial perceptions among vineyard workers; (2) to determine the most beneficial warm-up modality for vineyard workers.

METHODS

A cluster randomized study was implemented among 92 French vineyard workers. A 15 min single session of warm-up was implemented among four groups corresponding to four different conditions: (1) hybrid warm-up intervention (HWU); (2) dynamic warm-up intervention (DWU); (3) stretching warm-up intervention (SWU); (4) no warm-up intervention (CONTROL).

RESULTS

DWU showed significant increased performance (p < 0.05), increased heart rate (p < 0.001), better readiness to work (p < 0.05) and lower workload (p < 0.05) than the CONTROL. HWU showed a better readiness to work (p < 0.01). SWU showed better work quality (p < 0.05). However, the three different warm-up protocols did significantly not differ from the CONTROL group in terms of perceived pain intensity, and physical capacities.

CONCLUSION

The present findings confirm some beneficial acute effects on performance, heart rate and psychological perceptions of a single warm-up session performed before pruning. The DWU seems to be the most beneficial warm-up modality.

TRIAL REGISTRATION

NCT05425693. Registered 06/16/2022 in www.

CLINICALTRIALS

gov .

Chronic effects of stretching on range of motion with consideration of potential moderating variables: A systematic review with meta-analysis

BACKGROUND

It is well known that stretch training can induce prolonged increases in joint range of motion (ROM). However, to date more information is needed regarding which training variables might have greater influence on improvements in flexibility. Thus, the purpose of this meta-analysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables, such as stretching technique, intensity, duration, frequency, and muscles stretched, as well as sex-specific, age-specific, and/or trained state-specific adaptations to stretch training.

METHODS

We searched through PubMed, Scopus, Web of Science, and SportDiscus to find eligible studies and, finally, assessed the results from 77 studies and 186 effect sizes by applying a random-effect meta-analysis. Moreover, by applying a mixed-effect model, we performed the respective subgroup analyses. To find potential relationships between stretch duration or age and effect sizes, we performed a meta-regression.

RESULTS

We found a significant overall effect, indicating that stretch training can increase ROM with a moderate effect compared to the controls (effect size = -1.002; Z = -12.074; 95% confidence interval: -1.165 to -0.840; p < 0.001; I2 = 74.97). Subgroup analysis showed a significant difference between the stretching techniques (p = 0.01) indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic stretching. Moreover, there was a significant effect between the sexes (p = 0.04), indicating that females showed higher gains in ROM compared to males. However, further moderating analysis showed no significant relation or difference.

CONCLUSION

When the goal is to maximize ROM in the long term, proprioceptive neuromuscular facilitation or static stretching, rather than ballistic/dynamic stretching, should be applied. Something to consider in future research as well as sports practice is that neither volume, intensity, nor frequency of stretching were found to play a significant role in ROM yields.

Warm-up is an efficient strategy to prevent diurnal variation of short-term maximal performance in young basketball players

The objectives of this study were to investigate: 1) whether there were morning-to-evening differences in short-term maximal performance and 2) the impact of prolonged and specific warm-up on short-term maximal performance diurnal variations in young basketball players. Fifteen basketball players of both sexes (Male = 8; Female = 7; age: 14.4 ± 0.46 yr; weight: 64.7 ± 7.1 kg; height: 175.2 ± 6.6 cm; BMI: 21.1 ± 1.9 kg/m2) completed the following short-term maximal performance tests: CMJ with and without arm swing, Lane Agility Drill, Zig-Zag agility test with and without the ball, Sprint 20 m with and without the ball with the passage at 5 and 10 m. All tests were performed after the 15-min standard warm-up procedure (with static stretching) and/or 25-min specific warm-up (with prolonged running and dynamic stretching) in the morning and evening. Vertical jumping tests and all change-of-direction speed tests (with and without a ball) with superior responses were achieved in the evening after standard warm-up among all participants (p < 0.05). In contrast, superior short-term maximal performance was observed in the morning after prolonged and specific warm-up protocol (p < 0.05). It was concluded that specific and prolonged warm-up protocols are suitable strategy to prevent diurnal variation in short-term maximal performance in young basketball players.

Acute effects of different administration order of stretching exercises: effects on range of motion and cross-over effect

BACKGROUND

The aim of this manuscript is to investigate if stretching exercise administration order may influence outcomes pertinent to range of movement (ROM).

METHODS

A total sample of 108 participants was randomized into five groups. Eight sets of unilateral static stretching (SS) of 30s duration each with a 30s rest were administered to the right leg. One group underwent SS of the knee extensors (KE), another to the knee flexors (KF), another first to the KE and then to the KF, another first to the KF and then to the KE while the last group was used as control (CG). Each group was assessed for ROM of both lower limbs for either the KE and KF motion (passive hip extention [PHE] and passive straight leg raise [PSLR], respectively). Measures were assessed before (T0), immediately after (T1), and 15 minutes after the intervention (T2).

RESULTS

No differences were observed for time (T0 vs. T1 vs. T2) for all measures in the CG for both limbs. Time-x-group interactions were observed only in the intervention limb (P<0.0007 and 0.004, ES 0.73 and 0.55, for KE and KF, respectively). Within the intervention limb, a significant increase in the PHE was observed from T0 to T1 only in the KE and KF/KE groups. For measures of the PSLR, a significant increase was observed from T0 to T1 only in the KF and KE/KF groups. No differences neither for time or group were observed in the control limb.

CONCLUSIONS

Our results highlight that exercise administration order has an effect on ROM outcomes. Measures of ROM significantly increase only for the last stretched muscle in each intervention group. No crossover effect was observed in the contralateral limb.

The knowledge of movement experts about stretching effects: Does the science reach practice?

OBJECTIVE

Stretching is performed with numerous purposes in multiple settings such as prevention, rehabilitation, fitness training and sports. Its patterns of use substantially depend on the education and beliefs of health care and exercise professionals as they represent the multiplicators recommending and prescribing interventions to clients, patients and athletes. This study investigated movement experts' knowledge about the scientific evidence on stretching effects.

DESIGN

Survey study.

PARTICIPANTS

A total of 117 exercise and health professionals (physiotherapists, sports scientists, coaches) attending a training convention in Austria (male: n = 44, female: n = 73, 36±11 years) completed a digital survey. With its 22 items, the questionnaire addressed the movement experts' awareness of the evidence on stretching effects regarding a variety of related topics selected based on the findings of topical systematic reviews.

RESULTS

The majority of the individuals (57-88%) assumed positive effects of stretching on recovery, prevention of muscle injury, range of motion, muscular imbalance and artery elasticity. No or adverse effects were mostly claimed on bone injury prevention, maximal/explosive strength, and delayed-onset muscle soreness. In only 10 of 22 items, participants' classifications were in accord with the scientific evidence.

CONCLUSIONS

The awareness of research findings on stretching effects among exercise and health professionals is alarmingly low. Future studies may hence be geared to improve implementation and science communication.

Effects of percussion massage therapy, dynamic stretching, and static stretching on physical performance and balance

BACKGROUND

Percussion massage therapy is a popular approach in sport medicine for physical therapists, but few researchers have investigated the comparison with other intervention methods.

OBJECTIVE

This study aimed to examine the comparison of the effects of dynamic stretching, static stretching and percussive massage therapy on balance and physical performance in individuals.

METHODS

The participants who were 18-25 years of age, able to perform performance tests, did not have any orthopedic surgery, did not have problems during running and sudden turning, and did not have a professional sports history were included in the study. Participants were assigned randomly to three groups as dynamic stretching (DS) (n= 16), static stretching (SS) (n= 16) and percussive massage therapy (PMT) (n= 16) groups. Horizontal jumping test, T drill test and balance measurements on a single leg with open and closed eyes of all participants were recorded before and after applications.

RESULTS

When the values of the pre and post-treatment of all groups in the study were compared, significant improvements were observed in the t-test, horizontal jumping test and right/left foot balance with eyes open in DS group (p< 0.05). Significant improvements were observed in all values in the PMT group (p< 0.05). In the comparison of the differences between the groups, PMT group values were more significant than the SS group in all parameters.

CONCLUSION

Percussive massage therapy would be an alternative that can be used to increase the performance and balance of individuals before exercise.

Effects of Dynamic Stretching Combined with Manual Therapy on Pain, ROM, Function, and Quality of Life of Adhesive Capsulitis

This study was conducted to evaluate the effects of dynamic stretching combined with manual therapy on pain, range of motion, function, and quality of life in patients with adhesive capsulitis. The participants were randomly divided into two groups: the dynamic stretching combined with manual therapy (DSMT) group (n = 17) and the static stretching combined with manual therapy (SSMT) group (n = 17). Both groups received manual therapy for 10 min and two sessions per week for 4 weeks. The DSMT group also performed additional dynamic stretching for 20 min per session, two sessions per week for 4 weeks. The SSMT group practiced additional static stretching for 20 min per session, two sessions per week for 4 weeks. The pain, ROM, function, and quality of life were measured and evaluated before and after treatment. There were significant improvements in the outcomes of pain, flexion and abduction of shoulder ROM, Shoulder Pain and Disability Index (SPADI), and the physical component score and mental component score of the Short Form-36 (SF-36) in both groups. Additionally, the external and internal rotation of the shoulder ROM and the SF-36 general health factor increased significantly more in the A group (DSMT group) compared to the B group (SSMT). In conclusion, dynamic stretching plus manual therapy offers the same results as static stretching plus manual therapy, but with additional improvement in internal and external rotation.

Acute and Prolonged Effects of 300 sec of Static, Dynamic, and Combined Stretching on Flexibility and Muscle Force

Static stretching (SS), dynamic stretching (DS), and combined stretching (CS; i.e., DS+SS) are commonly performed as warm-up exercises. However, the stretching method with the greatest effect on flexibility and performance remains unclear. This randomized crossover trial examined acute and prolonged effects of SS, DS, and CS on range of motion (ROM), peak passive torque (PPT), passive stiffness, and isometric and concentric muscle forces. Twenty healthy young men performed 300 sec of active SS, DS, or CS (150-sec SS followed by 150-sec DS and 150-sec DS followed by 150-sec SS) of the right knee flexors on four separate days, in random order. Subsequently, we measured ROM, PPT, and passive stiffness during passive knee extension. We also measured maximum voluntary isometric and concentric knee flexion forces and surface electromyographic activities during force measurements immediately before, immediately after, and 20 and 60 min after stretching. All stretching methods significantly increased ROM and PPT, while significantly decreasing isometric knee flexion force (all p < 0.05). These changes lasted 60 min after all stretching methods; the increases in ROM and PPT and the decreases in isometric muscle force were similar. All stretching methods also significantly decreased passive stiffness immediately after stretching (all p < 0.05). Decreases in passive stiffness tended to be longer after CS than after SS or DS. Concentric muscle force was decreased after SS and CS (all p < 0.05). On the other hand, concentric muscle force was unchanged after DS, while the decreases in surface electromyographic activities during concentric force measurements after all stretching methods were similar. Our results suggest that 300 sec of SS, DS, and CS have different acute and prolonged effects on flexibility and muscle force.

Acute Effects of Various Stretching Techniques on Range of Motion: A Systematic Review with Meta-Analysis

Background

Although stretching can acutely increase joint range of motion (ROM), there are a variety of factors which could influence the extent of stretch-induced flexibility such as participant characteristics, stretching intensities, durations, type (technique), and muscle or joint tested.

Objective

The objective of this systematic review and meta-analysis was to investigate the acute effects of stretching on ROM including moderating variables such as muscles tested, stretch techniques, intensity, sex, and trained state.

Methods

A random-effect meta-analysis was performed from 47 eligible studies (110 effect sizes). A mixed-effect meta-analysis subgroup analysis was also performed on the moderating variables. A meta-regression was also performed between age and stretch duration. GRADE analysis was used to assess the quality of evidence obtained from this meta-analysis.

Results

The meta-analysis revealed a small ROM standard mean difference in favor of an acute bout of stretching compared to non-active control condition (ES = −0.555; Z = −8.939; CI (95%) −0.677 to −0.434; p  < 0.001; I2 = 33.32). While there were ROM increases with sit and reach (P  = 0.038), hamstrings (P  < 0.001), and triceps surae (P  = 0.002) tests, there was no change with the hip adductor test (P  = 0.403). Further subgroup analyses revealed no significant difference in stretch intensity (P  = 0.76), trained state (P  = 0.99), stretching techniques (P  = 0.72), and sex (P  = 0.89). Finally, meta-regression showed no relationship between the ROM standard mean differences to age (R2 = −0.03; P  = 0.56) and stretch duration (R 2 = 0.00; P  = 0.39), respectively. GRADE analysis indicated that we can be moderately confident in the effect estimates.

Conclusion

A single bout of stretching can be considered effective for providing acute small magnitude ROM improvements for most ROM tests, which are not significantly affected by stretch intensity, participants’ trained state, stretching techniques, and sex.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-023-00652-x.

The meta-analysis on joint range of motion (ROM) increases revealed a small effect size in favor of an acute bout of stretching compared to the control condition. Subgroup analysis revealed a significant increase in ROM with sit and reach, hamstrings, and triceps surae tests, but no improvement with the hip adductor tests. Whereas all moderating variables presented significant increases in ROM, further subgroup analyses revealed no significant difference in ROM gains with the stretch intensity, trained state of the participants, stretching techniques, and sex. A meta-regression showed no relationship between the effect sizes to age and stretch duration, respectively.

Comparison of Isolated or Combined Static Stretching and Foam Rolling on Knee Extensors' Function

Static stretching (SS), foam rolling (FR), and a combination of both are used as warm-ups for sports and training. However, no reports have compared or examined the warm-up effects of short-term interventions (i.e., 30-s). Therefore, this study was designed to compare and examine the effects of short-term SS, FR, and SS+FR on knee extensors. The dominant knee extensors of 14 male university students (22.0 ± 1.3 years old) were tested. Five conditions were randomized: 60-s SS, 60-s FR, 30-s SS+ 30-s FR, 30-s SS, and 30-s FR to examine differences in intervention method, duration, and combined. The measures were knee flexion range of motion (ROM), pain pressure threshold (PPT), tissue hardness, maximum voluntary contraction-isometric (MVC-ISO), and MVC-concentric (MVC-CON) torques, measured before and after the intervention. Knee flexion ROM (d = 0.40, d = 0.59, d = 0.54, d = 0.59, d = 0.52 respectively) and PPT (d = 0.77, d = 0.60, d = 0.90, d = 0.74, d = 0.52, respectively) were significantly increased (p < 0.01), and tissue hardness (d = -0.79, d = -0.63, d = -0.53, d = -0.59, d = -0.72, respectively) was significantly decreased (p < 0.01) in all conditions. However, MVC-ISO decreased significantly (p < 0.01) in the 60-s SS and 30-s SS conditions but did not affect MVC-CON in all conditions. The results of this study revealed that SS, FR, and SS+FR interventions for a short-term as a warm-up before exercise were effective in increasing ROM, PPT, and decreasing tissue hardness. However, SS intervention with more than 30-s on the knee extensors decreased muscle strength, so short-term FR intervention is recommended when the goal is to increase ROM while maintaining both MVC-ISO and MVC-CON torques. Similarly, a short-term FR intervention after a short-term SS can eliminate the effect of strength impairments.

A systematic review and net meta-analysis of the effects of different warm-up methods on the acute effects of lower limb explosive strength

OBJECTIVE

To evaluate the effects of different warm-up methods on the acute effect of lower limb explosive strength with the help of a reticulated meta-analysis system and to track the optimal method.

METHODS

R software combined with Stata software, version 13.0, was used to analyse the outcome metrics of the 35 included papers. Mean differences (MD) were pooled using a random effects model.

RESULTS

1) Static combined with dynamic stretching [MD = 1.80, 95% CI: (0.43, 3.20)] and dynamic stretching [MD = 1.60, 95% CI: (0.67, 2.60)] were significantly better than controls in terms of improving countermovement jump height (cm), and the effect of dynamic stretching was influenced by the duration of stretching (I2 = 80.4%), study population (I2 = 77.2%) and age (I2 = 75.6%) as moderating variables, with the most significant effect size for dynamic stretching time of 7-10min. 2) Only dynamic stretching [MD = -0.08, 95% CI: (-0.15, -0.008)] was significantly better than the control group in terms of improving sprint time (s), while static stretching [MD = 0.07, 95% CI: (0.002, 0.13)] showed a significant, negative effect. 3) No results were available to demonstrate a significant difference between other methods, such as foam axis rolling, and the control group.

CONCLUSION

The results of this review indicate that static stretching reduced explosive performance, while the 2 warm-up methods, namely dynamic stretching and static combined with dynamic stretching, were able to significantly improve explosive performance, with dynamic stretching being the most stable and moderated by multiple variables and dynamic stretching for 7-10min producing the best explosive performance. In the future, high-quality studies should be added based on strict adherence to test specifications.

Long-term static stretching can decrease muscle stiffness: A systematic review and meta-analysis

Stretch training increases the range of motion of a joint. However, to date, the mechanisms behind such a stretching effect are not well understood. An earlier meta-analysis on several studies reported no changes in the passive properties of a muscle (i.e., muscle stiffness) following long-term stretch training with various types of stretching (static, dynamic, and proprioceptive neuromuscular stretching). However, in recent years, an increasing number of papers have reported the effects of long-term static stretching on muscle stiffness. The purpose of the present study was to examine the long-term (≥2 weeks) effect of static stretching training on muscle stiffness. PubMed, Web of Science, and EBSCO published before December 28, 2022, were searched and 10 papers met the inclusion criteria for meta-analysis. By applying a mixed-effect model, subgroup analyses, which included comparisons of sex (male vs. mixed sex) and type of muscle stiffness assessment (calculated from the muscle-tendon junction vs. shear modulus), were performed. Furthermore, a meta-regression was conducted to examine the effect of total stretching duration on muscle stiffness. The result of the meta-analysis showed a moderate decrease in muscle stiffness after 3-12 weeks of static stretch training compared to a control condition (effect size = -0.749, p < 0.001, I2  = 56.245). Subgroup analyses revealed no significant differences between sex (p = 0.131) and type of muscle stiffness assessment (p = 0.813). Moreover, there was no significant relationship between total stretching duration and muscle stiffness (p = 0.881).

Corticospinal excitability and reflex modulation in a contralateral non-stretched muscle following unilateral stretching

PURPOSE

Muscle stretching effect on the range of motion (ROM) and force deficit in non-stretched muscle, and the underlying mechanisms, is an ongoing issue. This study aimed to investigate crossover stretching effects and mechanisms on the plantar flexor muscles.

METHODS

Fourteen recreationally active females (n = 5) and males (n = 9) performed six sets of 45-s static stretching (SS) (15-s recovery) to the point of discomfort of the dominant leg (DL) plantar flexors or control (345-s rest). Participants were tested for a single 5-s pre- and post-test maximal voluntary isometric contraction (MVIC) with each plantar flexor muscle and were tested for DL and non-DL ROM. They were tested pre- and post-test (immediate, 10-s, 30-s) for the Hoffman (H)-reflex and motor-evoked potentials (MEP) from transcranial magnetic stimulation in the contralateral, non-stretched muscle.

RESULTS

Both the DL and non-DL-MVIC force had large magnitude, significant (↓10.87%, p = 0.027, pƞ2 = 0.4) and non-significant (↓9.53%, p = 0.15, pƞ2 = 0.19) decreases respectively with SS. The SS also significantly improved the DL (6.5%, p < 0.001) and non-DL (5.35%, p = 0.002) ROM. The non-DL MEP/MMax and HMax/MMax ratio did not change significantly.

CONCLUSION

Prolonged static stretching improved the stretched muscle's ROM. However, the stretched limb's force was negatively affected following the stretching protocol. The ROM improvement and large magnitude force impairment (statistically non-significant) were transferred to the contralateral muscles. The lack of significant changes in spinal and corticospinal excitability confirms that the afferent excitability of the spinal motoneurons and corticospinal excitability may not play a substantial role in non-local muscle's ROM or force output responses.

Immediate Effects of Foam Roller and Stretching to the Lead Hip on Golfers Swing: A Randomized Crossover Trial

Golfers with decreased range of motion (ROM) of their leading hip internal rotation (IR) have increased lumbar rotation ROM and load. This study investigated the effects of foam roller (FR) applied to their leading hip muscles combined with stretching to the leading hip together with lumbar rotation ROM during the golf swing. The study design was a crossover design. Subjects were allocated to one of two groups comprising FR and dynamic stretching (FR + DS) or practice swing. Motion analysis was used to evaluate hip and lumbar angles during the golf swing. Data were compared using analysis of variance with Bonferroni correction using paired t-test's post hoc. The association between lead hip IR angle and lumbar spine left rotation (Lrot) angle was investigated using correlation analysis. Lead hip IR ROM during the golf swing was significantly greater in the FR + DS group (p = 0.034). The FR + DS group showed a moderate negative correlation between lead hip IR ROM and lower lumbar spine Lrot ROM during the golf swing (r = -0.522). The application of FR + DS might be useful to increase lead hip IR angle during the golf swing. Moreover, the application of FR + DS improves lead hip IR angle and may decrease lumbar spine rotation.

Potential Effects of Dynamic Stretching on Injury Incidence of Athletes: A Narrative Review of Risk Factors

The use of dynamic stretching as a replacement for static stretching in the warm-up is widespread based on the reports of static stretching-induced performance impairments. While acute and chronic static stretching has been reported to reduce musculotendinous injuries, especially with explosive and change of direction actions, the influence of dynamic stretching on injury incidence lacks a similar volume of literature for acute and chronic responses. It was the objective of this narrative review to examine the acute and training effects of dynamic stretching on injury incidence and possible moderating variables such as dynamic stretching effects on range of motion, strength, balance, proprioception, muscle morphology, and psycho-physiological responses. One study demonstrated no significant difference regarding injury incidence when comparing a dynamic stretching-only group versus a combined dynamic stretching plus static stretching group. The only other study examined functional dynamic stretching training with injured dancers and reported improved ankle joint stability. However, several studies have shown that dynamic activity with some dynamic stretching exercises within a warm-up consistently demonstrates positive effects on injury incidence. Regarding moderating variables, while there is evidence that an acute bout of dynamic stretching can enhance range of motion, the acute and training effects of dynamic stretching on strength, balance, proprioception, and musculotendinous stiffness/compliance are less clear. The acute effects of dynamic stretching on thixotropic effects and psycho-physiological responses could be beneficial for injury reduction. However, the overall conflicting studies and a lack of substantial literature compared with SS effects points to a need for more extensive studies in this area.

Reliability and measurement error of tests used for the assessment of throwing performance in overhead athletes: A systematic review

BACKGROUND

Throwing Performance (TP) is important in throwing sports. Several tests have been designed to assess TP, and the reliability of these tests was examined in various studies. The aim of this systematic review was to critically appraise and synthesize the studies that examined the reliability of TP tests.

METHODS

A systematic search was conducted on PubMed, Scopus, CINAHL and SPORTDiscus to identify studies related to TP and reliability. The quality of the included studies was examined through the Quality Appraisal of Reliability Studies (QAREL) tool. Reliability was assessed using the intraclass correlation coefficient (ICC), while responsiveness was assessed using the minimal detectable change (MDC). Sensitivity analysis was conducted to identify whether low-quality studies may have biased the recommendations of this review.

RESULTS

Seventeen studies were found eligible. The results showed a moderate level of evidence to suggest that TP tests have good reliability (ICC≥0.76). This recommendation was also applied separately when TP tests were used to measure throwing velocity, distance covered, endurance and throwing accuracy. Also, summated MDC scores were reported to assist coaches in decision-making when using TP tests to detect real performance changes. However, sensitivity analysis showed that there is a significant number of low-quality studies.

CONCLUSIONS

This review revealed that the tests used for throwing performance assessment are reliable; however, due to a significant number of low-quality studies, these results should be used cautiously. Important recommendations of this review may be used in future studies to design high-quality studies.

Are Acute Effects of Foam-Rolling Attributed to Dynamic Warm Up Effects? A Comparative Study

Over the last decade, acute increases in range of motion (ROM) in response to foam rolling (FR) have been frequently reported. Compared to stretching, FR-induced ROM increases were not typically accompanied by a performance (e.g., force, power, endurance) deficit. Consequently, the inclusion of FR in warm-up routines was frequently recommended, especially since literature pointed out non-local ROM increases after FR. However, to attribute ROM increases to FR it must be ensured that such adaptations do not occur as a result of simple warm-up effects, as significant increases in ROM can also be assumed as a result of active warm-up routines. To answer this research question, 20 participants were recruited using a cross-over design. They performed 4x45 seconds hamstrings rolling under two conditions; FR, and sham rolling (SR) using a roller board to imitate the foam rolling movement without the pressure of the foam rolling. They were also tested in a control condition. Effects on ROM were tested under passive, active dynamic as well as ballistic conditions. Moreover, to examine non-local effects the knee to wall test (KtW) was used. Results showed that both interventions provided significant, moderate to large magnitude increases in passive hamstrings ROM and KtW respectively, compared to the control condition (p = 0.007-0.041, d = 0.62-0.77 and p = 0.002-0.006, d = 0.79-0.88, respectively). However, the ROM increases were not significantly different between the FR and the SR condition (p = 0.801, d = 0.156 and p = 0.933, d = 0.09, respectively). No significant changes could be obtained under the active dynamic (p = 0.65) while there was a significant decrease in the ballistic testing condition with a time effect (p < 0.001). Thus, it can be assumed that potential acute increases in ROM cannot be exclusively attributed to FR. It is therefore speculated that warm up effects could be responsible independent of FR or imitating the rolling movement, which indicates there is no additive effect of FR or SR to the dynamic or ballistic range of motion.

Effects of Whole-Body Stretching Exercise during Lunch Break for Reducing Musculoskeletal Pain and Physical Exertion among Healthcare Professionals

Background and Objectives: To investigate the effect of whole-body stretching (WBS) exercise during lunch break for reducing musculoskeletal pain and physical exertion among healthcare professionals. Methods: Full-time healthcare professionals working in hospitals with more than one year of experience were invited to participate. Sixty healthcare professionals (age 37.15  ±  3.9 Years, height 1.61  ±  0.04 m, body mass 67.8  ±  6.3 kg, and BMI 26.5 ± 2.1 kg/m²) participated in this single-blinded, two-arm randomized controlled trial (RCT). Participants were divided into WBS (n = 30) and control (n = 30) groups. The WBS group performed a range of stretching exercises targeting the entire body during a lunch break period for 3 times a week for 6 weeks. The control group received an education program. Musculoskeletal pain and physical exertion were assessed using the Nordic musculoskeletal questionnaire and Borg rating of perceived exertion scale, respectively. Results: The 12-month prevalence of musculoskeletal discomfort among all healthcare professionals was highest in the low back region (46.7%), followed by the neck (43.3%), and then the knee (28.3%). About 22% of participants said that their neck discomfort impacted their job, while about 18% reported that their low back pain impacted their job. Results indicate that the WBS and education program had a beneficial impact on pain and physical exertion (p < 0.001). When comparing the two groups, the WBS group experienced a significantly greater decrease in pain intensity (mean difference 3.6 vs. 2.5) and physical exertion (mean difference 5.6 vs. 4.0) compared to an education program only. Conclusions: This study suggests that doing WBS exercises during lunchtime can help lessen musculoskeletal pain and fatigue, making it easier to get through the workday.

Response to Mechanical Properties and Physiological Challenges of Fascia: Diagnosis and Rehabilitative Therapeutic Intervention for Myofascial System Disorders

Damage to the fascia can cause significant performance deficits in high-performance sports and recreational exercise and may contribute to the development of musculoskeletal disorders and persistent potential pain. The fascia is widely distributed from head to toe, encompassing muscles, bones, blood vessels, nerves, and internal organs and comprising various layers of different depths, indicating the complexity of its pathogenesis. It is a connective tissue composed of irregularly arranged collagen fibers, distinctly different from the regularly arranged collagen fibers found in tendons, ligaments, or periosteum, and mechanical changes in the fascia (stiffness or tension) can produce changes in its connective tissue that can cause pain. While these mechanical changes induce inflammation associated with mechanical loading, they are also affected by biochemical influences such as aging, sex hormones, and obesity. Therefore, this paper will review the current state of knowledge on the molecular level response to the mechanical properties of the fascia and its response to other physiological challenges, including mechanical changes, innervation, injury, and aging; imaging techniques available to study the fascial system; and therapeutic interventions targeting fascial tissue in sports medicine. This article aims to summarize contemporary views.

How to Confuse Motor Control: Passive Muscle Shortening after Contraction in Lengthened Position Reduces the Muscular Holding Stability in the Sense of Adaptive Force

Adaptation to external forces relies on a well-functioning proprioceptive system including muscle spindle afferents. Muscle length and tension control in reaction to external forces is most important regarding the Adaptive Force (AF). This study investigated the effect of different procedures, which are assumed to influence the function of muscle spindles, on the AF. Elbow flexors of 12 healthy participants (n = 19 limbs) were assessed by an objectified manual muscle test (MMT) with different procedures: regular MMT, MMT after precontraction (self-estimated 20% MVIC) in lengthened position with passive return to test position (CL), and MMT after CL with a second precontraction in test position (CL-CT). During regular MMTs, muscles maintained their length up to 99.7% ± 1.0% of the maximal AF (AFmax). After CL, muscles started to lengthen at 53.0% ± 22.5% of AFmax. For CL-CT, muscles were again able to maintain the static position up to 98.3% ± 5.5% of AFmax. AFisomax differed highly significantly between CL vs. CL-CT and regular MMT. CL was assumed to generate a slack of muscle spindles, which led to a substantial reduction of the holding capacity. This was immediately erased by a precontraction in the test position. The results substantiate that muscle spindle sensitivity seems to play an important role for neuromuscular functioning and musculoskeletal stability.

The Effects of Static Stretching Intensity on Range of Motion and Strength: A Systematic Review

The aim of this study was to systematically review the evidence on the outcomes of using different intensities of static stretching on range of motion (ROM) and strength. PubMed, Web of Science and Cochrane controlled trials databases were searched between October 2021 and February 2022 for studies that examined the effects of different static stretching intensities on range of motion and strength. Out of 6285 identified records, 18 studies were included in the review. Sixteen studies examined outcomes on ROM and four on strength (two studies included outcomes on both ROM and strength). All studies demonstrated that static stretching increased ROM; however, eight studies demonstrated that higher static stretching intensities led to larger increases in ROM. Two of the four studies demonstrated that strength decreased more following higher intensity stretching versus lower intensity stretching. It appears that higher intensity static stretching above the point of discomfort and pain may lead to greater increases in ROM, but further research is needed to confirm this. It is unclear if high-intensity static stretching leads to a larger acute decrease in strength than lower intensity static stretching.

Resistance Training Induces Improvements in Range of Motion: A Systematic Review and Meta-Analysis

BACKGROUND

Although it is known that resistance training can be as effective as stretch training to increase joint range of motion, to date no comprehensive meta-analysis has investigated the effects of resistance training on range of motion with all its potential affecting variables.

OBJECTIVE

The objective of this systematic review with meta-analysis was to evaluate the effect of chronic resistance training on range of motion compared either to a control condition or stretch training or to a combination of resistance training and stretch training to stretch training, while assessing moderating variables.

DESIGN

For the main analysis, a random-effect meta-analysis was used and for the subgroup analysis a mixed-effect model was implemented. Whilst subgroup analyses included sex and participants' activity levels, meta-regression included age, frequency, and duration of resistance training.

DATA SOURCES

Following the systematic search in four databases (PubMed, Scopus, SPORTDiscus, and Web of Science) and reference lists, 55 studies were found to be eligible.

ELIGIBILITY CRITERIA

Controlled or randomized controlled trials that separately compared the training effects of resistance training exercises with either a control group, stretching group, or combined stretch and resistance training group on range of motion in healthy participants.

RESULTS

Resistance training increased range of motion (effect size [ES] = 0.73; p < 0.001) with the exception of no significant range of motion improvement with resistance training using only body mass. There were no significant differences between resistance training versus stretch training (ES = 0.08; p = 0.79) or between resistance training and stretch training versus stretch training alone (ES = - 0.001; p = 0.99). Although "trained or active people" increased range of motion (ES = 0.43; p < 0.001) "untrained and sedentary" individuals had significantly (p = 0.005) higher magnitude range of motion changes (ES = 1.042; p < 0.001). There were no detected differences between sex and contraction type. Meta-regression showed no effect of age, training duration, or frequency.

CONCLUSIONS

As resistance training with external loads can improve range of motion, stretching prior to or after resistance training may not be necessary to enhance flexibility.

The Combined Effect of Static Stretching and Foam Rolling With or Without Vibration on the Range of Motion, Muscle Performance, and Tissue Hardness of the Knee Extensor

ABSTRACT

Nakamura, M, Konrad, A, Kasahara, K, Yoshida, R, Murakami, Y, Sato, S, Aizawa, K, Koizumi, R, and Wilke, J. The combined effect of static stretching and foam rolling with or without vibration on the range of motion, muscle performance, and tissue hardness of the knee extensor. J Strength Cond Res 37(2): 322-327, 2023-Although the combination of static stretching (SS) and foam rolling (FR) is frequently used for warm-up in sports, the effect of the intervention order is unclear. This study compared mechanical tissue properties, pain sensitivity, and motor function after SS and FR (with and without vibration) performed in different orders. Our randomized, controlled, crossover experiment included 15 healthy male subjects (22.5 ± 3.3 years) who visited the laboratory 5 times (inactive control condition, FR + SS, FR vibration + SS, SS + FR, and SS + FR vibration ) with an interval of ≥48 hours. In each session, subjects completed three 60-second bouts of FR and SS, targeting the anterior thigh. Pressure pain threshold, tissue hardness, knee flexion range of motion (ROM), maximal voluntary isometric (MVC-ISO), and concentric (MVC-CON) torque, as well as countermovement jump height, were determined before and after the intervention. All interventions significantly ( p < 0.01) increased knee flexion ROM ( d = 0.78, d = 0.87, d = 1.39, and d = 0.87, respectively) while decreasing tissue hardness ( d = -1.25, d = -1.09, d = -1.18, and d = -1.24, respectively). However, MVC-ISO torque was significantly reduced only after FR + SS ( p = 0.05, d = -0.59). Our results suggest that SS should be followed by FR when aiming to increase ROM and reduce tissue hardness without concomitant stretch-induced force deficits (MVC-ISO, MVC-CON, and countermovement jump height). Additionally, adding vibration to FR does not seem to affect the magnitude of changes observed in the examined outcomes.

Strength and Conditioning Practices of Brazilian Olympic Sprint and Jump Coaches

Olympic coaches are likely to have adequate knowledge and implement effective training programs. This study aimed to describe and critically examine the strength and conditioning practices adopted by Brazilian Olympic sprint and jump coaches. Nineteen Olympic coaches (age: 50.2 ± 10.8 years; professional experience: 25.9 ± 13.1 years) completed a survey consisting of eight sections: 1) background information; 2) strength-power development; 3) speed training; 4) plyometrics; 5) flexibility training; 6) physical testing; 7) technology use; and 8) programming. It was noticed that coaches prioritized the development of explosiveness, power, and sprinting speed in their training programs, given the specific requirements of sprint and jump events. Nevertheless, unexpectedly, we observed: (1) large variations in the number of repetitions performed per set during resistance training in the off-season period, (2) a higher volume of resistance training prescribed during the competitive period (compared to other sports), and (3) infrequent use of traditional periodization models. These findings are probably related to the complex characteristics of modern competitive sports (e.g., congested competitive schedule) and the individual needs of sprinters and jumpers. Identification of training practices commonly used by leading track and field coaches may help practitioners and sport scientists create more effective research projects and training programs.

Effect of a home-based exercise training program on anthropometric characteristics and exercise performance during Covid-19 quarantine in young high-level kayak athletes

Purpose

The Covid-19 restriction exposed most athletes to insufficient training stimuli leading to detraining. This study investigated whether a home-based exercise training program could preserve body composition and exercise performance in young high-level kayak athletes during Covid-19 restriction.

Methods

Seventeen healthy young high-level kayak athletes (10 males and 7 females), aged 14.7 ± 1 yrs, participated in this study. A 7-week home-based training program was followed during Covid-19 restriction. Baseline measurements were assessed 4 weeks before Covid-19 pandemic and ended on 4 May 2020. Body composition, flexibility, isometric muscle trunk strength (Biodex), anaerobic power (30-s all-out trial), and aerobic capacity (4-min maximal test) were evaluated. Personal daily loads and wellness details were collected with AthleteMonitoring.com software.

Results

Home-based exercise training program was effective to improve flexibility (9.20 ± 2.85%) and lean body mass (3.96 ± 0.89%), to maintain muscle strength, anaerobic power, body mass, and body fat percentage but insufficient to maintain aerobic capacity (- 8.96 ± 2.49%).

Conclusion

The findings of the present study potentially highlight the importance of the implementation of such a program to minimize the detraining effect on young athletes during periods of movement restriction caused by pandemics.

Does Stretching Training Influence Muscular Strength? A Systematic Review With Meta-Analysis and Meta-Regression

ABSTRACT

Thomas, E, Ficarra, S, Nunes, JP, Paoli, A, Bellafiore, M, Palma, A, and Bianco, A. Does stretching training influence muscular strength? A systematic review with meta-analysis and meta-regression. J Strength Cond Res 37(5): 1145-1156, 2023-The aim of this study was to review articles that performed stretching training and evaluated the effects on muscular strength. Literature search was performed using 3 databases. Studies were included if they compared the effects on strength following stretching training vs. a nontraining control group or stretching training combined with resistance training (RT) vs. an RT-only group, after at least 4 weeks of intervention. The meta-analyses were performed using a random-effect model with Hedges' g effect size (ES). A total of 35 studies ( n = 1,179 subjects) were included in this review. The interventions lasted for a mean period of 8 weeks (range, 4-24 weeks), 3-4 days per week, applying approximately 4 sets of stretching of approximately 1-minute duration. The meta-analysis for the stretching vs. nontraining control group showed a significant small effect on improving dynamic (k = 14; ES = 0.33; p = 0.007) but not isometric strength (k = 8; ES = 0.10; p = 0.377), following static stretching programs (k = 17; ES = 0.28; p = 0.006). When stretching was added to RT interventions, the main analysis indicated no significant effect (k = 17; ES = -0.15; p = 0.136); however, moderator analysis indicated that performing stretching before RT sessions has a small but negative effect (k = 7; ES = -0.43; p = 0.014); the meta-regression revealed a significant negative association with study length (β = -0.100; p = 0.004). Chronic static stretching programs increase dynamic muscular strength to a small magnitude. Performing stretching before RT and for a prolonged time (>8 weeks) can blunt the strength gains to a small-to-moderate magnitude. Performing stretching in sessions distant from RT sessions might be a strategy to not hinder strength development.

Does static stretching change uniformly the quadriceps elasticity in physically actives subjects?

PURPOSE

Verify the acute responses of static stretching (SS) on the rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) elasticity and knee/hip range of motion (ROM). Additionally, to investigate if there are consistency among quadriceps muscle elasticity after SS.

METHODS

Acute effect of SS on pre-post-intervention design. Thirtheen healthy participants (both genders) proposed for a pre-post experimental design. RF, VM, and VL elasticity (strain ratio, SR) was evaluated bilaterally by ultrasound with quasi-static elastography. Higher SR values refer to more rigid tissues. A SS protocol of 3 series of 30 s was applied at right lower limb. The left lower limb was considered as control group. Also, photogrammetry evaluated the knee/hip ROM.

RESULTS

For SR muscle comparisons, VM was lower (less stiff) than VL and RF at pre- and post-SS. For time comparisons, no differences were observed for SR and ROM at pre- and post-SS. However, the effect size of the quadriceps SR at SS lower limb was higher than control.

CONCLUSION

Acute effects of SS did not change the quadriceps SR or knee/hip ROM in healthy and active subjects. Non-uniform quadriceps SR are observed (VM < VL and RF) independently of SS. Future studies should consider different protocols, muscles, and populations.

Effects of Speed and Amplitude of Dynamic Stretching on the Flexibility and Strength of the Hamstrings

Dynamic stretching for more than 90 seconds is useful for improving muscle strength, although dynamic stretching for 30 seconds or less is commonly used in sports settings. The effects of dynamic stretching are influenced by the speed and amplitude of stretching, but no study examined these factors for 30 seconds of dynamic stretching. Therefore, the purpose of the present study was to examine the effects of speed (fast- or slow-speed) and amplitude (normal- or wide amplitude) of dynamic stretching for 30 seconds on the strength (peak torque during maximum isokinetic concentric contraction) and flexibility (range of motion, passive torque at maximum knee extension angle, and muscle-tendon unit stiffness) of the hamstrings. The passive torque and muscle-tendon unit stiffness reflect stretching tolerance and viscoelastic properties of the hamstrings, respectively. Fifteen healthy participants performed 4 types of 30 seconds of dynamic stretching. The muscle strength and flexibility were measured before and immediately after the dynamic stretching. The range of motion did not change after dynamic stretching at low speed and normal amplitude (p = 0.12, d = 0.59, 103.3%), but it was increased by other interventions (p < 0.01, d = 0.90-1.25, 104.5-110.1%). In all interventions, the passive torque increased (main effect for time, p < 0.01, d = 0.51 - 0.74, 111.0 - 126.9%), and muscle-tendon unit stiffness did not change. The muscle strength increased only after dynamic stretching at fast speed with normal amplitude (p < 0.01, d = 0.79, 107.1%). The results of the present study indicated that 30 seconds of dynamic stretching at fast speed and with normal amplitude can be beneficial for the measured parameters.

Acute effects of long-lasting stretching and strength training on maximal strength and flexibility in the calf muscle

The so-called “stretch-induced force deficit” is known from a large amount of research. There are many theories trying to explain the stretch-induced force deficit and increases in the range of motion (ROM) which all offer a stretch training-specific explanation. However, when performing a commonly used strength training session, a reduced maximum strength (MSt) capacity can be assumed as well. Based on this, the aim of the study is to investigate the tension-induced force deficit due to a suprathreshold strength or stretching training stimulus. Therefore, 71 participants (age: 24.1 ± 4.2 years, height: 176.3 ± 5.7 cm, weight: 74.1 ± 7.5 kg) were divided into three groups: static stretching group (SST), strength training group (STR), and control group (CG). To investigate possible mechanical tension-induced force deficits, SST performed a long-lasting static stretching intervention for 1 h using an orthosis, while STR executed a common strength training intervention (5 × 12 repetition) for the plantar flexors. The results show a significant reduction of measured MSt as well as increased ROM for both SST and STR following the interventions. Consequently, we found similar acute effects of stretching and strength training regarding MSt and flexibility. We conclude that the decreased MSt capacities can possibly be attributed to mechanical tension-induced damage of the muscle that is not linked to a specific training method. The improvements in flexibility found in both intervention groups might be attributed to warm up effects when inducing high mechanical tension to large ankle joint angles.

Comparative Effects of Dynamic Stretching and Ice Bag Application On the Physical Performance in Recreational Basketball Players: A Randomized Crossover Study

Introduction: Researchers found that cryotherapy at the ankle joint heightened adjacent muscle activity and reflex amplitude, which facilitated greater force production at the ankle complex. Furthermore, cryotherapy appears to increase musculoarticular stiffness, which has been associated with heightened muscular performance at a joint. Aim and objective: the aim of the study is to examine the influence of dynamic stretching and IBA technique on the physical performance. Methodology: Total 20 healthy male basketball athletes encompassing two groups participated in the current study. The study consisted of two groups, Group A (ice bag application) and Group B (dynamic stretching). Cold compress was applied over the anterior thigh, posterior thigh, and calf. Subjects were assigned to Group A, and Group B, using Convenience sampling method. Each candidate performed the 5 minutes of jogging before taking intervention. All subjects performed three functional performance tests: Vertical Jump Test, Agility T-test & 20-meter sprint. Each participant attended an orientation session to become familiar with the testing procedures. Subjects were randomly assigned into two groups and exposed to a crossover study design. The experiment was performed on two separate occasions whereby one group received the dynamic stretching in the first session, while the other group uses the cryotherapy first. After 48 hours, (cooling session) on the next occasion, the groups were changed and the second group receives the cryotherapy, while the first group performs dynamic stretching. On both occasions, the dynamic stretching and cryotherapy interventions were the same. Between the sessions, the subjects will not allow to participate in any kind of vigorous physical activity. Results: The present study showed an increase in performance of recreational Basketball players by the combination of 5 minutes of warm up plus 6 min of dynamic stretching on the vertical jump height and 20-meter sprint.

The effects of facilitatory and inhibitory kinesiotaping of Vastus Medialis on the activation and fatigue of superficial quadriceps muscles

This study aimed to investigate how facilitatory and inhibitory KT of the Vastus Medialis affected the activation and the fatigue indices of VM, Vastus Lateralis (VL) and Rectus Femoris (RF) throughout a dynamic fatigue protocol. Seventeen collegiate athletes (Ten males, seven females, age: 24.76 ± 3.99 years, height: 1.73 ± 0.10 m, mass: 68.11 ± 8.54 kg) voluntarily participated in four dynamic fatigue protocol sessions in which no-tape (control condition), inhibitory, facilitatory and sham KTs were applied to the Vastus Medialis in each session. The protocol included 100 dynamic maximum concentric knee extensions at 90°/s using an isokinetic dynamometry device. The knee extensor muscle activities were recorded using wireless surface electromyography. The average muscle activity (Root mean square) during the first three repetitions and the repetitions number of 51-100, respectively, were used to calculate the before and after exhaustion muscle activity. Furthermore, median frequency slope during all repetitions was reported as the fatigue rate of muscles during different KT conditions and for the control condition (no-tape). The results showed neither muscle activation (significance for the main effect of KT; VM = 0.82, VL = 0.72, RF = 0.19) nor fatigue rate (significance for the main effect of KT; VM = 0.11 VL = 0.71, RF = 0.53) of the superficial knee extensor muscles were affected in all four conditions. These findings suggest that the direction of KT cannot reduce, enhance muscle activity or cause changes in muscle exhaustion. Future studies should investigate the generalizability of current findings to other populations.

Differential effects of dynamic and ballistic stretching on contralateral lower limb flexibility

BACKGROUND: Dynamic stretching (DS) and ballistic stretching (BS) are similar stretching methods, but the differences between them are unclear. OBJECTIVE: To examine the immediate effects of unilateral hamstring DS and BS on straight leg raise (SLR), knee flexion range of motion (KF-ROM), and KF and knee extension maximal isokinetic peak torque (KF-MIPT and KE-MIPT) of the bilateral limbs. METHODS: Twelve healthy adult men performed four sets of 2 min each of non-stretching, DS, or BS of the right lower extremity. Bilateral SLR, KF-ROM, KF-MIPT, and KE-MIPT were measured pre- and post-intervention; a three-way (intervention × limb × time) repeated-measures analysis of variance (ANOVA) was used. RESULTS: The SLR of the stretched limb (p< 0.01) was higher with DS than that pre-intervention. SLR (p< 0.01) and KF-ROM (p< 0.05) of the stretched limb and SLR (p< 0.05) and KF-ROM (p< 0.05) of the contralateral limb were higher with BS than those pre-intervention. There was no significant main effect or interaction between KF-MIPT and KE-MIPT. CONCLUSION: DS and BS had slightly different effects on ROM, and neither affected muscle strength; thus, combining the techniques during warm-up might be helpful.

Acute Effects of Static Stretching Combined with Vibration and Nonvibration Foam Rolling on the Cardiovascular Responses and Functional Fitness of Older Women with Prehypertension

Simple Summary

Thirty-seven percent of the US adult population have prehypertension, and a quarter to half of these over 65 years of age progress to hypertension in four years. Along with healthy diet, exercise or physical activity is one of the critical lifestyle factors for this population. General exercise recommendation or prescription to individuals who have cardiovascular risks is provided by organizations such as ACSM and AHA, but more detailed information and research are still needed. As the first component of any exercise program, finding the proper warm-up routine is important. We aimed to examine the acute immediate effects of three different warm-up protocols on cardiovascular responses and functional fitness testing in older women with prehypertension. Thirteen qualified subjects went through three protocols (static stretching with and without foam rolling, and stretching with vibration rolling) in three different sessions. Blood pressure was not altered only in the static stretching with foam rolling condition. Interestingly, adding the vibration component to the stretching increased the upper body flexibility and stretching. We therefore suggest the combination of static stretching with foam rolling as the safe and effective protocol for older women with prehypertension.

Abstract

We compared the effects of three warm-up protocols (static stretching (SS), static stretching with vibration foam rolling (SS + VFR), and static stretching with nonvibration foam rolling (SS + FR) on the blood pressure and functional fitness performance in older women with prehypertension. Thirteen older women went through different protocols in separate visits, and their systolic (SBP) and diastolic (DBP) blood pressure, heart rate, mean arterial pressure, brachial pulse pressure (BPP), functional fitness test (back scratch (BS), chair-sit-and-reach, 30 s arm curl (AC), 30 s chair stand, 2 min step, 8-foot up and go), and single-leg standing balance (SLB) were recorded. The SBP and BPP were significantly higher after SS and SS + VFR than after SS + FR. Both SS + FR and SS + VFR significantly improved the 2 min step, when compared with SS. Additionally, SS + VFR significantly improved the BS and AC performance. However, compared with SS and SS + FR, SS + VFR significantly reduced the SLB performance. Therefore, SS + FR may be a better warm-up protocol for older women in maintaining blood pressure. On the other hand, even though SS + VFR induced superior shoulder flexibility, aerobic endurance, and arm strength, it could impair balance.

The Time-Course Changes in Knee Flexion Range of Motion, Muscle Strength, and Rate of Force Development After Static Stretching

Previous studies have shown that longer-duration static stretching (SS) interventions can cause a decrease in muscle strength, especially explosive muscle strength. Furthermore, force steadiness is an important aspect of muscle force control, which should also be considered. However, the time course of the changes in these variables after an SS intervention remains unclear. Nevertheless, this information is essential for athletes and coaches to establish optimal warm-up routines. The aim of this study was to investigate the time course of changes in knee flexion range of motion (ROM), maximal voluntary isometric contraction (MVIC), rate of force development (RFD), and force steadiness (at 5 and 20% of MVIC) after three 60-s SS interventions. Study participants were sedentary healthy adult volunteers (n = 20) who performed three 60-s SS interventions of the knee extensors, where these variables were measured before and after SS intervention at three different periods, i.e., immediately after, 10 min, and 20 min the SS intervention (crossover design). The results showed an increase in ROM at all time points (d = 0.86-1.01). MVIC was decreased immediately after the SS intervention (d = -0.30), but MVIC showed a recovery trend for both 10 min (d = -0.17) and 20 min (d = -0.20) after the SS intervention. However, there were significant impairments in RFD at 100 m (p = 0.014, F = 6.37, η_p ² = 0.101) and 200 m (p < 0.01, F = 28.0, η_p ² = 0.33) up to 20 min after the SS intervention. Similarly, there were significant impairments in force steadiness of 5% (p < 0.01, F = 16.2, η_p ² = 0.221) and 20% MVIC (p < 0.01, F = 16.0, η_p ² = 0.219) at 20 min after the SS intervention. Therefore, it is concluded that three 60-s SS interventions could increase knee flexion ROM but impair explosive muscle strength and muscle control function until 20 min after the SS intervention.

An Intense Warm-Up Does Not Potentiate Performance Before or After a Single Bout of Foam Rolling

Foam rolling (FR) is a common intervention used as a warm-up to increase the range of motion (ROM) of a joint, without changes in subsequent performance. It has been shown that, in similar techniques (e.g., stretching), an additional intense warm-up can lead to performance potentiation. However, to date, it is not clear if this also holds true for FR, and if this effect is similar in both sexes. Thus, the purpose of this study was to compare the effects of an intense warm-up either before or after FR with the effects of FR without any additional intense warm-up, in both females and males. In total, 27 volunteers (14 male, 13 female) visited the laboratory on three separate days. Each participant was randomly assigned to one of the three interventions. ROM was assessed with a Sit n' Reach box, and countermovement jump (CMJ) height with a force plate, both before and after the interventions. In addition, maximum voluntary isometric contraction (MVIC) peak torque and maximum voluntary dynamic contraction (MVDC) peak torque were assessed with a dynamometer. ROM increased to the same extent following the interventions in all groups, with a large magnitude of change (P < 0.001; d = 1.12 to 1.83). In addition, male participants showed significantly higher increases in ROM when the intense warm-up was performed after FR (P < 0.001; d = 1.44), but not without the intense warm-up (P = 0.45; d = 0.57) or when the intense warm-up was performed before FR (P = 0.24; d = 0.69). No significant changes in CMJ height, MVIC peak torque, or MVDC peak torque were observed (P > 0.05). We therefore conclude that the time-efficient athlete might skip further intense warm-up, besides FR, when the goal is to increase ROM and to sustain performance parameters.