Do whole body vibration exercises affect lower limbs neuromuscular activity in populations with a medical condition? A systematic review

Effects of whole-body vibration training on physical function, activities of daily living, and quality of life in patients with stroke: a systematic review and meta-analysis

Purpose: This systematic review and meta-analysis aimed to evaluate the efficacy of whole-body vibration training (WBVT) in patients with stroke, specifically focusing on its effects on physical function, activities of daily living (ADL), and quality of life (QOL). Additionally, potential moderators influencing WBVT outcomes were explored. Methods: We conducted a systematic search of PubMed, Embase, and Cochrane Library from inception to September 2022. Eligible studies were randomized controlled trials employing WBVT in patients with stroke. Two investigators independently extracted the data and calculated the standardized mean difference (SMD) using random-effect models. Results: Twenty-five studies involving 991 patients were included in this meta-analysis. WBVT demonstrated significant reductions in spasticity (SMD = -0.33, 95% CI = -0.61 to -0.06, p = 0.02), improvements in motor function (SMD = 0.39, 95% CI = 0.16 to 0.61, p < 0.01), and enhancements in balance function (SMD = 0.28, 95% CI = 0.09 to 0.47, p < 0.01) in patients with stroke. However, no significant effects were observed for gait (SMD = -0.23, 95% CI = -0.50 to 0.04, p = 0.10), ADL (SMD = -0.01, 95% CI = -0.46 to 0.44, p = 0.97), or QOL (SMD = 0.12, 95% CI = -0.30 to 0.53, p = 0.59). Subgroup analyses revealed that variable frequency vibration and side-alternating vibration exhibited significant efficacy in reducing spasticity and improving motor and balance functions, while fixed frequency vibration and vertical vibration did not yield significant therapeutic benefits in these domains. Conclusion: Our findings indicate that WBVT may serve as a viable adjunct therapy for stroke patients to alleviate spasticity and enhance motor and balance functions. Variable frequency and side-alternating vibration appear to be crucial factors influencing the therapeutic effects of WBVT on these dysfunctions. Nonetheless, WBVT did not show significant effects on gait, ADL, or QOL in stroke patients. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier (CRD42022384319).

Acute Effects of Whole-Body Vibration on Resting Metabolic Rate and Substrate Utilisation in Healthy Women

The aim of the study was to determine the acute effects of single-whole-body vibration (WBV) on resting metabolic rate (RMR) and carbohydrate−lipid profile of blood in young, healthy women. The participants, in a randomised controlled crossover study, participated in two trials: WBV and a vibration simulation (placebo). The WBV was performed in the prone position and cycloidal-oscillatory vibration was used. The RMR measurement (calorimetry) was performed: before the WBV, during WBV, immediately after the completion of WBV, and 1 h after the completion of WBV. For biochemical analyses, venous blood was collected. During WBV, there was a significant increase in RMR compared to baseline. Immediately after and 1 h following the end of the WBV, RMR was close to baseline levels (p > 0.05). The increased energy expenditure resulted from the increased utilisation of carbohydrates and proteins during the vibration. In the placebo condition, there were no significant changes over time in the level of the studied indices during calorimetry. The WBV had no significant effects on the level of glucose in the blood. The applied vibration did not significantly affect the concentration of the analysed lipid indices, which were within the physiological norms for all measurements. Results indicate the need for further research to establish the physiological mechanisms underlying the observed effects of WBV on resting metabolic rate.

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.

Vibration detection: its function and recent advances in medical applications

Vibrations are all around us. We can detect vibrations with sensitive skin mechanoreceptors, but our conscious awareness of the presence of vibrations is often limited. Nevertheless, vibrations play a role in our everyday life. Here, we briefly describe the function of vibration detection and how it can be used for medical applications by way of whole body vibration. Strong vibrations can be harmful, but milder vibrations can be beneficial, although to what extent and how large the clinical relevance is are still controversial. Whole body vibration can be applied via a vibrating platform, used in both animal and human research. Recent findings make clear that the mode of action is twofold: next to the rather well-known exercise (muscle) component, it also has a sensory (skin) component. Notably, the sensory (skin) component stimulating the brain has potential for several purposes including improvements in brain-related disorders. Combining these two components by selecting the optimal settings in whole body vibration has clear potential for medical applications. To realize this, the field needs more standardized and personalized protocols. It should tackle what could be considered the "Big Five" variables of whole body vibration designs: vibration amplitude, vibration frequency, method of application, session duration/frequency, and total intervention duration. Unraveling the underlying mechanisms by translational research can help to determine the optimal settings. Many systematic reviews on whole body vibration end with the conclusion that the findings are promising yet inconclusive. This is mainly because of the large variation in the "Big Five" settings between studies and incomplete reporting of methodological details hindering reproducibility. We are of the opinion that when (part of) these optimal settings are being realized, a much better estimate can be given about the true potential of whole body vibration as a medical application.

Cross-training effect of chronic whole-body vibration exercise: a randomized controlled study

Purpose: To determine whether unilateral leg whole-body vibration (WBV) strength training induces strength gain in the untrained contralateral leg muscle. The secondary aim was to determine the potential role of spinal neurological mechanisms regarding the effect of WBV exercise on contralateral strength training.Materials and Methods: Forty-two young adult healthy volunteers were randomized into two groups: WBV exercise and Sham control. An isometric semi-squat exercise during WBV was applied regularly through 20 sessions. WBV training was applied to the right leg in the WBV group and the left leg was isolated from vibration. Sham WBV was applied to the right leg of participants in the Control group. Pre- and post-training isokinetic torque and reflex latency of both quadricepses were evaluated.Results: The increase in the strength of right (vibrated) knee extensors was 9.4 ± 10.7% in the WBV group (p = .001) and was 1.2 ± 6.6% in the Control group (p = .724). The left (non-vibrated) extensorsvibrated) knee extensors w4 ± 8.4% in the WBV group (p = .038), whereas it decreased by 1.4 ± 7.0% in the Control (p = .294). The strength gains were significant between the two groups. WBV induced the reflex response of the quadriceps muscle in the vibrated ipsilateral leg and also in the non-vibrated contralateral leg, though with a definite delay. The WBV-induced muscle reflex (WBV-IMR) latency was 22.5 ± 7.7 ms for the vibrated leg and 39.3 ± 14.6 ms for the non-vibrated leg.Conclusions: Chronic WBV training has an effect of the cross-transfer of strength to contralateral homologous muscles. The WBV-induced muscular reflex may have a role in the mechanism of cross-transfer strength.

Acute Effects of Whole-Body Vibration Alone or in Combination With Maximal Voluntary Contractions on Cardiorespiratory, Musculoskeletal, and Neuromotor Fitness in Obese Male Adolescents

Musculoskeletal and neuromotor fitness (MSMF) is reduced in obesity. Physical exercise (including whole-body vibration exercise [WBVE]) is reported to improve components related to MSMF. The aim of the study is to evaluate the acute effects of WBVE and maximal voluntary contraction (MVC), alone and in combination, on the cardiorespiratory and MSMF in obese adolescents. Eight obese adolescents performed 3 tests (WBVE, MVC, and MVC + WBVE) in different days and randomly. The outcome measures were diastolic blood pressure (DBP), systolic blood pressure (SBP), mean arterial pressure (MAP), heart rate (HR), peripheral oxygen saturation (SpO₂), handgrip strength (HS), one-leg standing balance (OLSB) test, sit-and-reach (SR) test, stair climbing test (time: T_SCT and power: P_SCT), and sit-to-stand test (time: T_STSand power: P_STS). No significant changes were observed in SBP, DBP, MAP, and SpO₂ after the 3 tests, only an HR increase being observed after MVC + WBVE (P < .01) and MVC alone (P < .05). No significant differences were found in HS, OLSB, T_STS, and P_STS after the 3 different sessions. An increase in SR was found after MVC + WBVE, MVC, and WBVE (P < .01, P < .05, and P < .01, respectively), while a decrease in T_SCT (P < .01) and an increase in P_SCT were observed only after WBVE (P < .01). Taking into account the positive WBVE effects on cardiorespiratory and MSMF, WBVE might represent a nonimpact, viable, and safe exercise suitable for obese patients, which need MSMF improvement without overloading joints.

Evaluation of Whole-Body Vibration Exercise on Neuromuscular Activation Through Electromyographic Pattern of Vastus Lateralis Muscle and on Range of Motion of Knees in Metabolic Syndrome: A Quasi-Randomized Cross-Over Controlled Trial

Metabolic syndrome (MetS) is related to overweight and obesity, and contributes to clinical limitations. Exercise is used for the management of MetS individuals, who are often not motivated to perform this practice. Whole body vibration exercise (WBVE) produces several biological effects, besides being safe, effective, and feasible for MetS individuals. This pseudo-randomized and cross-over controlled trial study aimed to analyze the effects of WBVE on MetS individuals’ neuromuscular activation using the surface electromyography (sEMG) pattern (root mean square (RMS)) of the vastus lateralis (VL) muscle and on the range of motion (ROM) of the knees. Participants (n = 39) were allocated to two groups: the treatment group (TG), which was exposed to WBVE, and the control group (CG). WBVE interventions were performed twice a week, for a period of 5 weeks. ROM and sEMG were analyzed at baseline, after the first session, and before and after the last session. sEMG (%RMS) significantly increased in the acute effect of the last session of WBVE (108.00 ± 5.07, p < 0.008, right leg; 106.20 ± 3.53, p < 0.02, left leg) compared to the CG. ROM did not significantly change in TG or CG. In conclusion, 5 weeks of WBVE exerted neuromuscular effects capable of increasing VL muscle RMS in individuals with MetS, this effect being potentially useful in the physical rehabilitation of these individuals.

Evaluation of the temperature of posterior lower limbs skin during the whole body vibration measured by infrared thermography: Cross-sectional study analysis using linear mixed effect model

BACKGROUND

Whole body vibration exercise (WBVE) has been shown to improve muscular strength and power, and increase peripheral blood flow. The aim of this study was to evaluate the behavior of the skin temperature (Tsk) on regions of the lower limbs from an acute bout of WBVE.

METHODS AND FINDINGS

Cross-sectional study approved by local ethics committee (Certificado de Apresentação para Apreciação Ética-CAAE-19826413.8.0000.5259) and Trial registration (Registro Brasileiro de Ensaios Clínicos-REBEC-RBR-738wng). Using Infrared thermography (IRT), Tsk and thermal symmetry of the posterior lower extremities (thigh, knee, calf and heel) were examined in 19 healthy participants. IRT was assessed during 60-second WBVE exposures of 0, 30 and 50 Hz. From the adjusted linear mixed effects model, vibration frequency, time and regions of the lower extremity were significant (p<0.001). However, the variable laterality was not significant (p = 0.067) and was excluded from the adjusted statistical model. The adjusted model was significant (p<0.00001) and all variables in the model were significant (p<0.01) indicating that Tsk decreases with time, independently of the vibration frequency. The value of the Pseudo-R-Squared for the model was 0.8376. The presented mathematical model of the current study may be useful to justify the patterns observed for all vibration frequencies between and 0 and 50 Hz. The main limitations of the study were the reduced time of the intervention and not having evaluated other regions of the body.

CONCLUSIONS

The acute exposure of 60-second mechanical vibration has effect on the behavior of Tsk of the posterior region of the lower limbs, which is likely to be associated with a decrease on the blood flow due to WBVE. It is speculated that during WBVE a greater supply of blood is required where the body responds by shunting blood flow from the skin to working muscle in the first seconds of exercise. Further investigative work is required to verify this hypothesis.

Targeted Subcutaneous Vibration With Single-Neuron Electrophysiology As a Novel Method for Understanding the Central Effects of Peripheral Vibrational Therapy in a Rodent Model

Very little is known about the effects of whole body vibration on the supraspinal central nervous system. Though much clinical outcome data and mechanistic data about peripheral neural and musculoskeletal mechanisms have been explored, the lack of central understanding is a barrier to evidence-based, best practice guidelines in the use of vibrational therapy. Disparate methods of administration render study to study comparisons difficult. To address this lack of uniformity, we present the use of targeted subcutaneous vibration combined with simultaneous in vivo electrophysiological recordings as a method of exploring the central effects of peripheral vibration therapy. We used implanted motors driven by both Grass stimulators and programmed microcontrollers to vary frequency and location of stimulation in an anesthetized in vivo rat model while simultaneously recording firing rate from gamma-aminobutyric acid (GABA) neurons in the ventral tegmental area. We show that peripheral vibration can alter GABA neuron firing rate in a location- and frequency-dependent manner. We include detailed schematics and code to aid others in the replication of this technique. This method allows for control of previous weaknesses in the literature including variability in body position, vibrational intensity, node and anti-node interactions with areas of differing mechanoreceptor densities, and prefrontal cortex influence.

Effects of Single or Multiple Sessions of Whole Body Vibration in Stroke: Is There Any Evidence to Support the Clinical Use in Rehabilitation?

Background and Purpose

Recently new technologies and new techniques, such as Whole Body Vibration (WBV), have been introduced by the health and fitness industry to pursue therapeutic or physical performance goals. The aim of this systematic review is to investigate the effectiveness of single or multiple WBV sessions alone or in association with traditional rehabilitation, compared to traditional rehabilitation therapy or with sham therapy in poststroke patients.

Methods

Randomized Control Trials and controlled clinical trials written in English between January 1st, 2003, and December 31st, 2017, were selected from PubMed, Cochrane-Central-Register-of-Controlled-Trials, and Physiotherapy-Evidence-Database (PEDro). The single WBV session and multiple sessions' effects were assessed. Study characteristics, study population, intervention protocols, effects of WBV sessions, and adverse events were investigated with a descriptive analysis.

Results

The search reported 365 articles and after screening and removal of duplicates, 11 manuscripts with PEDro score≥6/10 were selected (391 poststroke patients). Study characteristics, study population, intervention protocols (frequencies, amplitude of vibration, and peak acceleration), effects of a single or multiple WBV sessions, and adverse events were analyzed. They have been investigated with particular attention to bone turnover, structure and muscle functions, spasticity, postural control and risk of falls, functional mobility, somatosensory threshold, and activity and participation. Comparing WBV group with control group no significant benefits emerged.

Discussion

This systematic review included studies involving participants with non homogeneous characteristics, just considering the incorporation of studies on individuals with chronic and postacute stroke. Despite these limits, WBV treatment has no significant risks for patients and shows interesting effects of WBV treatment in Structure and muscle functions, Spasticity and Postural control.

Conclusions

Even though treatment with WBV appears safe and feasible, there is insufficient evidence to support its clinical use in poststroke rehabilitation at this point. More studies assessing other functional tests and with more specific treatment protocols are needed.