Effects of Whole-Body Vibration Training and Blood Flow Restriction on Muscle Adaptations in Women: A Randomized Controlled Trial

Blood flow restriction therapy with exercise are no better than exercise alone in improving athletic performance, muscle strength, and hypertrophy: a systematic review and meta-analysis

BACKGROUND

The benefits of Blood Flow Restriction Therapy (BFRT) have gained attention in recent times.

OBJECTIVE

This review aimed to evaluate the immediate (up to 24 hours), intermediate (up to 6 weeks), and long term (6-10 weeks) effects of BFRT plus exercises (EX) compared to EX only on athletic performance (sprint and jump performance), muscle strength, and hypertrophy in athletes and physically active population.

METHODS

A literature search was conducted to select randomized controlled trials across four electronic databases from inception till April 2021. The search yielded twenty-seven studies in total.

RESULTS

Based on eligibility criteria, twenty-one studies were analyzed. No differences were found between both groups for immediate (standardized mean difference [SMD] -0.02, 95% confidence interval [CI] -0.31, 0.27) and long-term effects (SMD -0.30, 95%CI -0.90, 0.30) on sprint performance. For jump performance, no significant effect was observed immediately (SMD -0.02 (95% CI -1.06, 1.02) and long term (SMD -0.40 (95% CI -1.46, 0.67). Similarly, muscle torque at intermediate (SMD 0.90 (95% CI -1.01, 2.81) and long term (SMD -0.54 (95% CI -1.19, 0.12), muscle strength at intermediate (SMD 1.12 (95% CI 0.20, 2.04), and long term (SMD -0.07 (95% CI -0.56, 0.42) also showed non-significant effects. Muscle hypertrophy at intermediate (SMD 0.16 (95% CI -0.31, 0.63) and long term (SMD -0.20 (95% CI -0.90, 0.50) were not statistically significant.

CONCLUSIONS

There was no significant difference observed in BFRT plus EX group compared to the EX-group on athletic performance, muscle strength, and muscle hypertrophy.

The Effects of Vibration Exposure on Lower-Limb Extensor Muscles' Stiffness, Elasticity, and Strength Responses in Untrained Young Individuals: A Randomized Controlled Trial

OBJECTIVES

The whole-body vibration (WBV) effects on muscle strength show inconsistent results. Moreover, there is no study about the WBV effect on stiffness, elasticity, and muscle strength. Therefore, the study aimed to examine the effect of WBV exposure with static squat posture on the stiffness, elasticity, and strength of the lower-limb extensor muscles.

MATERIAL AND METHODS

Forty healthy untrained young adults were divided into WBV and control groups. The experimental group received WBV exposure on 2 nonconsecutive days of the week, for 6 weeks. The MyotonPRO device was used for the assessment of the knee extensor and the ankle dorsiflexors' stiffness and elasticity. Isometric muscle strength was evaluated with a hand-held dynamometer. All measurements were done by the same assessor at baseline, and the following 6 weeks.

RESULTS

Significant group-by-time interactions were found for the elasticity scores of the right (d = 0.84, P = .01) and left (d = 0.77, P = .02) ankle dorsiflexors. Similar to the elasticity measurements, significant group-by-time interactions were observed in the muscle strength scores of the right (d = 0.45, P = .046) and left (d = 1.25, P < .001) ankle dorsiflexors. No significant effects were observed in any of the evaluated muscle stiffness measurements (P > .05), and there was no significant group-by-time interaction in knee-extensor muscle strength and elasticity scores (P > .05).

CONCLUSIONS

The study results indicate that if the ankle dorsiflexor strength and elasticity are desired to be increased, the 6-week WBV exposure in a static squat posture can be used in healthy individuals.

EFFECTS OF VIBRATION TRAINING ON UPPER LIMBS OF VOLLEYBALL PLAYERS

ABSTRACT Introduction: The research on vibration training has experienced a period of development in many projects, such as badminton, handball, long jump, and volleyball. However, there is still no quantitative research evaluation of its effects on the development of shoulder, elbow, and upper limb muscle strength in volleyball athletes. It is believed that a specific training protocol with vibration may bring benefits to sensory-motor performance and muscle strength implementation in volleyball athletes. Objective: To study the effects of vibration training on upper limb function in volleyball players. Methods: Literature, experimental, and mathematical-statistical research methods were used to explore the relationship between vibration training under the muscle strength of the upper limbs and their joints. Results: The vibration training with an amplitude of 2mm, at a vibration frequency between 30Hz and 45Hz, the frequency of vibration training presented inversely proportional to the effect of vibration training. Conclusion: Vibration training showed the benefits of motor coordination and increased muscle strength in volleyball players. An appropriate vibration training strategy can maximize athletes’ skills, such as body coordination, flexibility, and jumping ability. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

EFFECTS OF VIBRATION TRAINING ON THE PHYSICAL FITNESS OF SHORT-DISTANCE SWIMMERS

ABSTRACT Introduction Vibration training is a widespread exercise. Existing experimental results show that using vibration strength exercises under the same loading conditions can improve the muscular strength of swimmers’ lower limbs. Objective This paper especially studies the effect of vibration exercise on the physical quality of swimmers under various conditions. Methods The athletes were randomly divided into two groups: the experimental group and the control group. The experimental group used a vibrometer to exercise the lower limb muscles. The control group engaged only in routine training. After eight weeks of practice, the runners tested in the 100m, 150m, 200m, and 400m. The present article also explores the relationship between swimmers of different ages. Results Compared to the control group, there was a significant difference in maximum hip extensor volume between the experimental and control groups. There was also a significant difference between the two groups (P<0.05). The most significant increase in maximal exercise capacity between the two groups was in the ankle. The change in maximum load between the two groups was also significant (P<0.01). Conclusion The vibration training method can improve the swimmer’s knee flexor group. Swimmers can improve their body coordination by performing vibration exercises. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Current and Future Trends in Strength and Conditioning for Female Athletes

Participation by female athletes in competitive sport has increased dramatically since the inception of Title IX, although female athletes are represented significantly less than their male counterparts in strength and conditioning (S&C) literature. This is apparent when examining current identified trends in the field, such as implementation of blood flow restriction (BFR) training, functional assessments to predict injuries, or the ever-increasing use of technology in sports. The aim of this review is to examine three prevalent trends in contemporary S&C literature as they relate to female athletes in order to expose areas lacking in research. We conducted journal and database searches to progressively deepen our examination of available research, starting first with broad emerging themes within S&C, followed next by an inquiry into literature concerning S&C practices in females, ending finally with a review of emerging topics concerning female athletes. To this end, 534 articles were reviewed from PubMed, Academic Search Complete, Google Scholar, CINAHL, MEDLINE, and Web of Science. Results demonstrate the utility of implementing BFR, functional movement assessments, and various technologies among this population to expand representation of female athletes in S&C literature, improve athletic capabilities and performance, and decrease potential for injury over time.

Acute Response of Sclerostin to Whole-body Vibration with Blood Flow Restriction

Blood flow restriction may augment the skeletal response to whole-body vibration. This study used a randomised, crossover design to investigate the acute response of serum sclerostin and bone turnover biomarkers to whole-body vibration with blood flow restriction. Ten healthy males (mean±standard deviation; age: 27±8 years) completed two experimental conditions separated by 7 days: (i) whole-body vibration (10 1-minute bouts of whole-body vibration with 30 s recovery) or (ii) whole-body vibration with lower-body blood flow restriction (10 cycles of 110 mmHg inflation with 30 s deflation during recovery). Fasting blood samples were obtained immediately before and immediately after exercise, then 1 hour, and 24 hours after exercise. Serum samples were analysed for sclerostin, cross-linked C-terminal telopeptide of type I collagen, and bone-specific alkaline phosphatase. There was a significant time × condition interaction for bone-specific alkaline phosphatase (p=0.003); bone-specific alkaline phosphatase values at 24 hours post-exercise were significantly higher following whole-body vibration compared to combined whole-body vibration and blood flow restriction (p=0.028). No significant time × condition interaction occurred for any other outcome measure (p>0.05). These findings suggest that a single session of whole-body vibration combined with blood flow restriction does not significantly affect serum sclerostin or bone turnover biomarkers.

Reliability of pelvic floor muscle surface electromyography (sEMG) recordings during synchronous whole body vibration

The primary aim of the study was to assess intraday and interday reliability of surface electromyography (sEMG) reflex activity of the pelvic floor muscles during synchronous whole-body vibration (S-WBV) of two intensities (30Hz/2mm; 40Hz/4mm) using band-stop filter and high-pass filter signal processing. The secondary aim of the study was to assess intraday and interday (test-retest) reliability of sEMG obtained from maximal voluntary contraction (MVC) test. We evaluated the intraday reliability of sEMG recordings obtained during sessions 1 and 2 performed on the same day. The sessions consisting of maximal voluntary pelvic floor muscle contraction and synchronous vibration sets with 1-hour rest in-between sessions 1 and 2 in healthy nulliparous women. The next intraday reliability was evaluated between the results of sessions 3 and 4 performed on the same day but followed at an interval of 4 weeks. to include the entire menstrual cycle. The interday reliability was determined based on the results of sessions 1 and 3 using the intraclass correlation coefficient (ICC 3,3). The intraday ICCs for band-stop filtered mean and median sEMG frequency and mean normalized sEMG_RMS amplitude of the 30Hz/2mm (ICC = 0.89–0.99) and 40Hz/4mm vibration (ICC = 0.95–0.99) indicated substantial reproducibility. The intraday reliability of high-pass filter at 100-450Hz for these parameters was also substantial (30Hz/2mm ICC of 0.92 to 0.98; 40Hz/4mm ICC of 0.88 to 0.98). The interday reliability (session 1 vs. session 3) of the mean normalized sEMG_RMS amplitude for band-stop filtered means of 40 Hz/4mm and 30Hz/2mm vibration recordings was substantial (ICC = 0.82 and 0.93). However, ICCs of the mean and median frequency were indicative of fair reliability (ICC of 0.43 to 0.59). The interday reliability of mean normalized sEMG_RMS amplitude for high-pass filter at 100-450Hz was substantial (30Hz/2mm ICC of 0.90; 40Hz/4mm ICC of 0.73) for the 30Hz/2mm S-WBV and moderate (ICC = 0.73) for the 40/4mm S-WBV. The ICCs for mean and median sEMG frequency ICCs indicated slight to fair reproducibility (ICC of 0.16 to 0.56). The intraday reliability of the strongest MVC contraction and average MVC turned out substantial (ICC = 0.91–0.98). The interday reliability coefficients of the strongest MVC contraction and average MVCs were 0.91 and 0.82, respectively. Concluded, the intraday reliability proved satisfactory for all variables; however, the interday comparison showed sufficient ICC levels only for the mean amplitude. We therefore recommend this parameter should be used when analyzing PFM sEMG recorded during vibration. ICCs of the mean and median frequency for both signal processing methods were indicative of insufficient reliability and did not reach the threshold for usefulness. Our study showed similar reliability of PFM sEMG during S-WBV in case of the two filtering methods used.

Associations Between Measures of Physical Activity and Muscle Size and Strength: A Systematic Review

Objective

To determine whether physical activity is associated with lower limb muscle size and strength within the general population.

Data Sources

Six databases were systematically searched from inception using 3 main constructs: lower extremity, muscle volume, and muscle strength.

Study Selection

Studies that measured physical activity (using either objective or subjective measurements), lower limb muscle size, and strength were included. Available discrete group data were standardized using previously published age- and sex-specific normative values prior to analysis.

Data Extraction

The final analysis included 47 studies from an initial yield of 5402 studies. Standardized scores for outcome measures were calculated for 97 discrete groups.

Data Synthesis

As anticipated, lower limb muscle size was positively correlated with lower limb muscle strength (r=0.26, P<.01; n=4812). Objectively measured physical activity (ie, accelerometry, pedometry) (n=1944) was positively correlated with both lower limb muscle size (r=0.30, P<.01; n=1626) and lower limb strength (r=0.24, P<.01; n=1869). However, subjectively measured physical activity (ie, questionnaires) (n=3949) was negatively associated with lower limb muscle size (r=–0.59, P<.01; n=3243) and lower limb muscle strength (r=–0.48, P<. 01; n=3882).

Conclusions

This review identified that objective measures of physical activity are moderately associated with lower limb muscle size and muscle strength and can, therefore, be used to predict muscle changes within the lower limbs associated with exercise-based rehabilitation programs.