Ia EPSPs in rat spinal motoneurons are potentiated after a 5-week whole-body vibration

2021 ◽  
Author(s):  
Piotr Krutki ◽  
Włodzimierz Mrówczyński ◽  
Jan Celichowski ◽  
Marcin Bączyk
Keyword(s):  
Whole Body Vibration ◽  
Input Resistance ◽  
Muscle Spindles ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Resting Membrane Potential ◽  
Tonic Vibration Reflex ◽  
Body Vibration ◽  
Synaptic Excitation ◽  
The Mean

Whole-body vibration (WBV) is often applied as an alternative method for strength training or to prevent muscle force decrease. Previous studies indicated that WBV induced: 1) changes in the contractile parameters predominantly of fast motor units, 2) higher motoneuron excitability, and 3) higher motoneuron firing rates at lower stimulus intensities compared with the control. In this study, we evaluated the influence of WBV on Ia monosynaptic input from muscle spindles because the tonic vibration reflex is responsible for the enhancement of muscle activity observed after WBV. The aim was to answer the question of whether repeated activation of muscle spindles during WBV may result in altered synaptic excitation of motoneurons. WBV was performed on adult male Wistar rats, 5 days per week, for 5 weeks, and each daily session consisted of four 30-s runs of vibration at 50 Hz. Fast-type medial gastrocnemius motoneurons were investigated intracellularly in deeply anesthetized animals in the experimental (n=7, 34 motoneurons) and control (n=7, 32 motoneurons) groups. Monosynaptic Ia EPSPs were evoked by electrical stimulation of afferent fibers from the synergistic lateral gastrocnemius and soleus muscles. Data were analyzed using a mixed linear model. WBV induced an increase of the mean EPSP amplitude by 28% (P=0.025), correlated with the resting membrane potential and input resistance, and a shortening of the mean EPSP rise time by 11% (P=0.012). The potentiation of synaptic excitation of motoneurons indicates that WBV may support rehabilitation or training processes aimed at increasing muscle strength on the basis of increased motoneuronal drive.

Adaptations in physiological properties of rat motor units following 5 weeks of whole-body vibration

2013 ◽  
Vol 38 (9) ◽  
pp. 913-921 ◽  
Author(s):  
Dawid Łochyński ◽  
Marcin Bączyk ◽  
Dominik Kaczmarek ◽  
Maria Jolanta Rędowicz ◽  
Jan Celichowski ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Whole Body Vibration ◽  
Motor Units ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Force Frequency ◽  
Body Vibration ◽  
Myosin Heavy Chain Isoform ◽  
Twitch Contraction

The purpose of the study was to determine the effects of 5-week whole-body vibration (WBV) on contractile parameters and force–frequency relationship of functionally isolated motor units of the rat medial gastrocnemius muscle: fast fatigable (FF), fast fatigue-resistant (FR), and slow (S). Moreover, myosin heavy chain isoform content was quantified. Following WBV, the maximum tetanic force of FF units was increased by ∼25%. The twitch half-relaxation time in all types of motor units and the twitch contraction time in FR units were shortened. The twitch-to-tetanus force ratio was decreased and the force–frequency curves were shifted rightwards in S and FR units. Myosin heavy chain distribution was not changed. These findings suggest modifications of the excitation–contraction coupling towards shortening of a twitch contraction. The observed increase in force of FF units may contribute to gains in muscle dynamic strength reported following WBV treatment.

The Effects of Acute and Long-Term Whole-Body Vibration Training on the Postural Control During Cognitive Task in Patients With Chronic Ankle Instability

2021 ◽  
pp. 1-8
Author(s):  
Seyed Abolfazl Tohidast ◽  
Rasool Bagheri ◽  
Ziaeddin Safavi-Farokhi ◽  
Mohammad Khaleghi Hashemian ◽  
Cyrus Taghizadeh Delkhosh
Keyword(s):  
Postural Control ◽  
Postural Stability ◽  
Center Of Pressure ◽  
Ankle Instability ◽  
Lateral Displacement ◽  
Whole Body Vibration ◽  
Chronic Ankle Instability ◽  
Whole Body ◽  
Body Vibration ◽  
The Mean

Context: Chronic ankle instability (CAI) is a common problem associated with impaired postural stability. Whole-body vibration (WBV) has been developed to improve muscle function and reportedly improves postural stability. The aim of this study was to evaluate the effect of 12 sessions of WBV on postural control during standing postural task in participants with CAI. Design: A controlled clinical trial study. Methods: Sixteen participants with CAI and 16 healthy participants aged between 20 and 40 years included in this study. They received WBV (30-Hz frequency, 3 series of four 45-s exercises with a 45-s rest) for a total of 12 sessions, 2 session per week for 6 weeks. Postural control was assessed by center of pressure (COP) parameters, including mean and SD in the anterior–posterior and medial–lateral displacement during single-leg standing. Assessments were done before and immediately after the first session and after the 12th session of WBV, with opened and closed eyes associated with easy and difficult cognitive tasks. Results: The results showed that the SD of COP displacement in the x-axis was significant in eyes opened and SD of COP displacement in the x- and y-axes were significant between groups in the eyes-opened, and eyes-closed conditions (P < .05). Analysis of variance indicated that the effect of WBV training was significant for the mean of COP displacement in the y-axis. Post hoc indicated that the effect of 12 sessions of WBV on the mean of COP displacement was significant in the CAI group (P < .05). However, the acute effect of WBV was not significant on the COP displacement in all axes (P > .05). Conclusion: Higher postural sway associated with postural cognitive interactions might be considered in the rehabilitation of CAI. Twelve sessions of WBV might induce some improvement in postural control with the method of WBV used in this study.

Additive Effect of Repeated Bouts of Individualized Frequency Whole Body Vibration on Postural Stability in Young Adults

2014 ◽  
Vol 30 (4) ◽  
pp. 529-533 ◽  
Author(s):  
D. Clark Dickin ◽  
Jacqueline E. Heath
Keyword(s):  
Young Adults ◽  
Postural Control ◽  
Postural Stability ◽  
Whole Body Vibration ◽  
Sensory Information ◽  
Muscle Spindles ◽  
Whole Body ◽  
Body Vibration ◽  
Multiple Exposures ◽  
Environment Study

Whole body vibration (WBV) has been shown to improve force and power output as well as flexibility and speed, with improvements suggested to result from reduced electromechanical delays, improved rate of force development, and sensitivity of muscle spindles. Fixed frequency studies on postural control have been somewhat equivocal; however, individualized frequency protocols have shown promising results in other motor tasks. To assess this, 18 healthy young adults experienced three 4-minute WBV sessions with postural control assessed before vibration, after multiple exposures, and during recovery, with altered levels of sensory information available to the participants. Sway velocity, sway path length, and sway area were assessed in each environment. Study findings revealed that stability was impacted following WBV, with more challenging environments eliciting improvements persisting for 20 minutes. When the environment was less challenging, postural stability was impaired; however, the effects dissipated quickly (10-20 min). It was determined that exposure to individualized frequency WBV served to impair postural control when the challenge was low, but resulted in heightened stability when the overall challenge was high and vestibular information was needed for stability.

scholarly journals Experimental Evidence of the Tonic Vibration Reflex during Whole-Body Vibration of the Loaded and Unloaded Leg

PLoS ONE ◽  
2013 ◽  
Vol 8 (12) ◽  
pp. e85247 ◽  
Author(s):  
Lisa N. Zaidell ◽  
Katya N. Mileva ◽  
David P. Sumners ◽  
Joanna L. Bowtell
Keyword(s):  
Experimental Evidence ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Tonic Vibration Reflex ◽  
Body Vibration

Asynchronous Alterations of Muscle Force and Tendon Stiffness Following 8 Weeks of Resistance Exercise with Whole-Body Vibration in Older Women

2017 ◽  
Vol 25 (2) ◽  
pp. 287-294 ◽  
Author(s):  
Seong-won Han ◽  
Dae-yeon Lee ◽  
Dong-Sung Choi ◽  
Boram Han ◽  
Jin-Sun Kim ◽  
...  
Keyword(s):  
Older Women ◽  
Muscle Force ◽  
Whole Body Vibration ◽  
Medial Gastrocnemius ◽  
Whole Body ◽  
Training Period ◽  
Combined System ◽  
Tendon Stiffness ◽  
Body Vibration ◽  
Training Groups

This study aimed to examine whether muscle force and tendon stiffness in a muscle-tendon complex alter synchronously following 8-week whole-body vibration (WBV) training in older people. Forty older women aged 65 years and older were randomly assigned into control (CON, n = 15) and whole-body vibration (WBV) training groups (exposure time, n = 13; vibration intensity, n = 12). For the training groups, a 4-week detraining period was completed following the training period. Throughout the training/detraining period, force of the medial gastrocnemius (MG) muscle and stiffness of the Achilles tendon were assessed four times (0, 4, 8, and 12 weeks) using a combined system of dynamometer and ultrasonography. While muscle force gradually increased throughout the training period (p < .05), a significant increase in tendon stiffness was observed after 8 weeks (p < .05). These findings indicated that, during the early phase of WBV training, muscle force and tendon stiffness changed asynchronously, which might be a factor in possible musculotendinous injuries.

scholarly journals WHOLE-BODY VIBRATION TRAINING PROTOCOLS IN OBESE INDIVIDUALS: A SYSTEMATIC REVIEW

2019 ◽  
Vol 25 (6) ◽  
pp. 527-533
Author(s):  
Fábio Antônio Tenório de Melo ◽  
Gislane Ferreira de Melo ◽  
Severino Leão de Albuquerque Neto ◽  
Rogério Wagner da Silva ◽  
Nanci Maria de França ◽  
...  
Keyword(s):  
Systematic Review ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Oxygen Absorption ◽  
Mineral Density ◽  
Level Of Evidence ◽  
Body Vibration ◽  
Physiological Variables ◽  
The Mean ◽  
Training Protocols

ABSTRACT Obesity is a chronic degenerative disease. Whole-body vibration (WBV) devices make it possible to control the intensity of exercises through their variables: frequency, amplitude and vibration time, thus enabling interventions in these populations. The objective of this study was to review the applications, protocols and results of WBV devices in obese individuals. A systematic literature review was conducted using the descriptors and terms verified in DeCS (LILACS and SCIELO) and MeSH (PubMED). Of the thirteen studies selected, seven used an experimental and six a quasi-experimental methodological design. Eleven studies analyzed chronic responses and two studies acute responses to WBV training. Frequency values ranged between 30 and 35 Hz, amplitude was around 2 mm, and in terms of intensity, most of the training protocols used a gradual increase in WBV throughout the intervention. Eight studies added dynamic exercises and extra loads to the WBV. The mean total WBV exposure time varied around 20’ distributed in 1 or 2 series, with vibration times of 30” to 60” and the same rest time. The mean frequency of interventions was around 2 to 3 times a week, with a mean intervention time of 10 months. The main results include: decrease in body weight and improvement in the physiological variables of oxygen absorption, bone mineral density and arterial profile, indicating that WBV can be a safe tool in the fight against obesity and its implications. Level of Evidence II. Systematic Review of Level II Studies.

Comparison of Whole-Body Vibration Exposures on Older and Newer Haulage Trucks at an Aggregate Stone Quarry Operation

2008 ◽  
Author(s):  
Alan G. Mayton ◽  
Christopher C. Jobes ◽  
Richard E. Miller
Keyword(s):  
Data Collection ◽  
Whole Body Vibration ◽  
Small Sample ◽  
Whole Body ◽  
Body Vibration ◽  
Exposure Limit ◽  
The Mean ◽  
Vector Sum ◽  
Mean Vector ◽  
Sampling Times

Exposure to whole-body vibration (WBV) and the postural requirements of the job have been identified as important risk factors in the development of musculoskeletal disorders of the back among workers exposed to a vibratory environment. This paper focuses on preliminary results of WBV data collected for two groups of haulage trucks — four older trucks from manufacturer A (MFR-A) and two newer trucks from manufacturer B (MFR-B). All of the trucks and their respective seats were considered to be in good working order during the study. Measurement periods for the truck groups had similarities, but varied from 2 to 58 minutes. Sampling times for the older trucks included a mean of 19.5 minutes and a standard deviation (STD) of 6.5 minutes compared to a mean of 40.8 minutes and a STD of 12.1 minutes for the newer trucks. Data collection coincided with the approximate delivery and first operation of the new trucks, and occurred approximately 12 months apart under similar weather and road conditions, and with the same drivers except an additional driver was included with the older trucks. Truck routes were somewhat different in that quarry production had changed location in the time between data collection activities. Overall, the results suggest that the newer trucks may provide better overall isolation to drivers/operators from WBV exposure compared to the older trucks operating at the quarry; although, this will need to be confirmed with additional measurements. Considering the higher variability and shorter sampling times for the older trucks, the results should be viewed with caution. For two of seven trials, the older trucks showed that seats amplified vibration, i.e., a transmissibility (T) &gt;1.0. Seat T for the older trucks ranged from 0.31 to 1.17 with a mean of 0.77 and STD of 0.32. This contrasted with the newer haulage trucks where seats amplified vibration in 3 of 8 trials. In this case, T did not vary greatly and ranged from 0.87 to 1.05 with a mean of 0.97 and STD of 0.07. Regarding older trucks, in five of seven trials, the seat (output) data of weighted root-mean square (RMS) acceleration (wRMSz) for the dominant z-axis exceeded the action level of 0.5 m/s2 action level recommended by the European Union Good Practice Guide for WBV (EUGPG) and levels exceeded the recommended exposure limit of 1.15 m/s2 in two of the seven trials. The wRMSz values for the older trucks varied from 0.41 to 1.83 m/s2 with a mean of 0.99 and STD of 0.57. Similarly, newer trucks indicated a narrower range of wRMSz from 0.38 to 0.95 m/s2. The mean wRMSz was lower for the newer trucks at 0.58 m/s2 with a STD of 0.23 m/s2. Similarly, newer trucks indicated wRMSz reached or exceeded the action level in four of eight trials. None of the trials with the new trucks showed wRMSz levels that reached or exceeded the recommended 1.15 m/s2 exposure limit. As an indicator of driver/operator discomfort, overall weighted total RMS acceleration (vector sum) values seem to show a “rougher” ride for the older trucks. The vector sum values for these trucks ranged widely from 0.70 to 2.59 m/s2 and, in four of seven trials, showed levels greater than 1.40 m/s2. The mean vector sum was 1.44 m/s2 with a STD of 0.75 m/s2. Comparatively, the newer trucks exhibited less variation with a range from 0.69 to 1.59 m/s2. The mean vector sum was 1.02 m/s2 with a STD of 0.35 m/s2. Vibration dose values for the dominant z-axis (VDVz), gave a sense of vehicle jarring/jolting conditions. All trials with the older trucks were within the recommended EUGPG action level of 9.1 m/s1.75. On the other hand, in three of eight trials, both newer trucks exceeded this action level with values of 9.18, 12.58, and 13.21 m/s1.75. Neither truck group showed VDVz that exceeded the exposure limit of 21 m/s1.75. A statistical analysis was not conducted, since the differences reported between truck groups may not be statistically significant owing to the relatively small sample size. Road conditions, changes in the truck routes, and driver/operator differences (e.g., stopping and turning) are possible factors in the higher VDV for the newer trucks.

Resistive exercises, with or without whole body vibration, prevent vertebral marrow fat accumulation during 60 days of head-down tilt bed rest in men

2012 ◽  
Vol 112 (11) ◽  
pp. 1824-1831 ◽  
Author(s):  
Guy Trudel ◽  
Elizabeth Coletta ◽  
Ian Cameron ◽  
Daniel L. Belavý ◽  
Martin Lecompte ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Whole Body Vibration ◽  
Lumbar Vertebrae ◽  
Bed Rest ◽  
Whole Body ◽  
Marrow Fat ◽  
Fat Accumulation ◽  
Body Vibration ◽  
Fat Fraction ◽  
The Mean

Fat accumulates in the bone marrow of lumbar vertebrae with bed rest. Exercise with or without whole body vibration may counter this effect. Our objectives were to measure 1) the vertebral fat fraction (VFF) of men subjected to bed rest who performed resistive exercises with (RVE, n = 7) or without whole body vibration(RE, n = 8) or no exercise (CTR, n = 9) using three MRI techniques; and 2) changes in peripheral blood counts. Twenty-four healthy men (age: 20–45 yr) underwent −6° head-down tilt (HDT) bed rest for 60 days. MRI was performed using three techniques (fat saturation, proton spectroscopy, and in and out of phase) to measure the fat fraction of L3, L4, and/or L5 at baseline, mid-HDT, and end-HDT. Erythrocytes and leukocytes were counted at HDT days 19, 33, 47, 54, and 60. The mean absolute VFF was increased in the CTR group at mid-HDT and end-HDT (+3.9 ± 1.3 and +3.6 ± 1.2%, respectively, both P < 0.05). The RE group had a smaller VFF change than the CTR group at mid-HDT (−0.9 ± 1.2 vs. +3.9 ± 1.3%, P < 0.05). The RVE group had a smaller VFF change than the CTR group at end-HDT (−2.6 ± 1.9 vs. +3.5 ± 1.2%, P < 0.05). Erythrocyte counts were increased in all groups at HDT day 19 and HDT day 33 and in the RE group at HDT day 54 (all P < 0.05). Bed rest for 60 days at −6° HDT increased lumbar VFF in men beyond natural involution. RVE and RE regimens effectively prevented VFF accumulation. Higher erythrocyte counts were not altered by RVE or RE. Whole body vibration, along with RE administered to people with prolonged immobility, may prevent fat accumulation in their bone marrow.

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