Nov 03, 2020
Effects of Whole-Body Vibrations on Neuromuscular Fatigue
- Milos Kalc1,
- Ramona Ritzmann2,
- Vojko Strojnik3
- 1University of Maribor, Faculty of Medicine, Institute of Sport Medicine;
- 2Department of Biomechanics, Rennbahnklinik;
- 3University of Ljubljana, Faculty of sport
External link: https://doi.org/10.7717/peerj.10388
Protocol Citation: Milos Kalc, Ramona Ritzmann, Vojko Strojnik 2020. Effects of Whole-Body Vibrations on Neuromuscular Fatigue. protocols.io https://dx.doi.org/10.17504/protocols.io.beadjaa6
Manuscript citation:
Kalc M, Ritzmann R, Strojnik V, Effects of whole-body vibrations on neuromuscular fatigue: a study with sets of different durations. PeerJ doi: 10.7717/peerj.10388
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: March 26, 2020
Last Modified: November 03, 2020
Protocol Integer ID: 34853
Keywords: Level of voluntary activation, Maximum voluntary contraction, Whole bodt vibration, Double interpolated twitch technique, Doublets, high to low frequency ratio, neuromuscular fatigue, single twitch, double twitch, electrical stimulation
Abstract
Purpose: The aim of the study was to investigate the origin and magnitude of neuromuscular fatigue induced by half-squat whole-body vibration.
Methods: Ten young, recreationally trained adults participated in six fatiguing protocols, each consisting of several sets of 30, 60 or 180 s static squatting superimposed with vibration (WBV30, WBV60, WBV180) or without vibration (SHAM30, SHAM60, SHAM180) for a total exercise exposure of 9-minutes in each trial. Maximum voluntary contraction (MVC), level of voluntary activation (%VA), single twitch peak torque (TWPT), low- (T20) and high-frequency (T100) doublets, and low-to-high-frequency fatigue ratio (T20/100) were assessed before, immediately after, 15 and 30 minutes after each fatiguing protocol.
Guidelines
Study design:
each subject performed three different fatiguing exercises interventions with WBV and three exercise interventions in a SHAM condition without WBW (SHAM) to discriminate the effect of WBV. Each intervention contained a cumulative exercise period with a duration of 9 minutes divided into different sets (either 18 x 30 s or 9 x 60 s or 3 x 180 s), with 120 s rest between sets. Each intervention was randomly executed on different visits at the same day-time with at least 7 days rest in-between.
Materials
Equipment
DS7A
NAME
HV Constant Current Stimulator
TYPE
Digitimer
BRAND
1
SKU
Equipment
10 mm Ag–AgCl electrode
NAME
Type 0601000402
TYPE
Controle Graphique Medical
BRAND
1
SKU
LINK
Cathode
SPECIFICATIONS
Equipment
ELECTRODES PERFORMANCE 50 X 100MM PIN
NAME
Electrode
TYPE
Compex
BRAND
1
SKU
Equipment
Isometric machine with a force transducer
NAME
Isometric dynamometer
TYPE
Custom Made
BRAND
1
SKU
Force transducer (MES, Maribor, Slovenia)
SPECIFICATIONS
Equipment
Galileo Fit
NAME
Whole body vibration platform - WBV
TYPE
Novotec Medical GmbH
BRAND
1
SKU
Equipment calibration
Equipment calibration
We calibrated the
Equipment
Isometric machine with a force transducer
NAME
Isometric dynamometer
TYPE
Custom Made
BRAND
1
SKU
Force transducer (MES, Maribor, Slovenia)
SPECIFICATIONS
prior to each measuring session.
The signal of the dynamometer was connected to
Equipment
PowerLab 16/35 (PL3516)
NAME
DAQ - data acquisition hardware
TYPE
ADInstruments
BRAND
1
SKU
running
Software
LabChart
NAME
Windows XP
OS
ADInstruments Australia
DEVELOPER
The same machine has been used in several other studies
CITATION
CITATION
We calibrated the force transducer, by hanging a 20 kg weight. We read the Voltage transformation to calculate the exerted torque.
Pre experiment procedures
Pre experiment procedures
We invited the subject to seat on the Isometric dynamometer in order to adjust the seating position and lever arm. The subject was positioned in an upright sitting position, the trunk at 100° leaning against the backrest of the isometric dynamometer, fixed by straps over the pelvis and a horizontal pad over the distal third of the thigh. The knee joint axis was aligned with the mechanical axis of the dynamometer. The shin pad was placed just above to the medial malleolus. The right knee joint was fixed at a 60° angle (0° = full extension)
Femoral nerve stimulation electrode placement
We invited the participants to flex their hip from in a seated position, while we palpated the iliac fossa
Schematic view of the leg and the stimulation
electrode placement
and placed the electrode (cathode) into the femoral triangle.
Equipment
10 mm Ag–AgCl electrode
NAME
Type 0601000402
TYPE
Controle Graphique Medical
BRAND
1
SKU
LINK
Cathode
SPECIFICATIONS
A larger self-adhesive electrode placed over the gluteal fold served as an anode.
Equipment
ELECTRODES PERFORMANCE 50 X 100MM PIN
NAME
Electrode
TYPE
Compex
BRAND
1
SKU
Femoral nerve test stimulation
Electrical impulses (single, square wave, 1-ms duration) elicited by a high voltage constant current electrical stimulator
Equipment
DS7A
NAME
HV Constant Current Stimulator
TYPE
Digitimer
BRAND
1
SKU
were used to trigger the muscle response, which was detected as a change in knee extensors torque.
We elicited several impulses (3 in average, max 6) at a fixed intensity of 20 mA at a frequency of 0.1 Hz and slightly moving the cathode in order to find the spot which produced the highest response (highest torque).
Warm-up
Warm-up
00:06:00 warm-up routine consisting of bench stepping (20 cm high) at a frequency of 0.5 Hz , with a leg exchange each minute
00:02:00 rest
Pre experiment procedure
Pre experiment procedure
The stimulation intensity to elicit the maximum knee extensor isometric twitch was determined in each subject after Warm-up (starting from 10 mA ) progressively increasing the stimulation intensity by 10 mA until no further increase in torque was observed despite further increment in current. The current at maximal twitch torque was additionally increased by a factor of 1.5 to obtain a supra-maximal stimulus. This intensity was maintained for the entire visit.
PRE - assessment (t0)
PRE - assessment (t0)
Schematic representation of the assessment timeline and the change in knee extensors torque
Maximal voluntary contraction with double twitch interpolated techniques
Subjects were asked to perform a 5 s maximal isometric voluntary (MVC) knee extension
CITATION
The signal was smoothed using a 0.5 s window moving average filter and peak torque (MVC) was retained for analysis. The double twitch interpolated technique
CITATION
was performed by superimposing a 100 Hz doublet on the isometric plateau (TMVC). A second analogous stimulation 100 Hz (T100) on the relaxed muscle followed after 3 s.
The ratio of the amplitude of the TMVC over T100 was then calculated to obtain the level of voluntary activation (%VA):
High- and low-frequency doublets
The torque change induced by the paired high- (100 Hz , i.e. 10 ms interstimulus interval) and low-frequency (20 Hz , i.e. 50 ms interstimulus interval) supramaximal electrical stimuli were analyzed.
CITATION
CITATION
The following parameters were obtained: peak torque from 100 Hz doublet (T100), peak torque from 20 Hz doublet (T20) and the low- to thehigh-frequency ratio (T20/100) was calculated using the following formula:
This ratio was then used as a surrogate of low- to high-frequency tetanic stimulation.
CITATION
Single twitch
The torque change induced by the single supramaximal femoral nerve stimuli was analysed.
CITATION
The following parameters were obtained: 1) the maximum torque value (TWPT);
Intervention
Intervention
Intervention
The interventions were performed on
Equipment
Galileo Fit
NAME
Whole body vibration platform - WBV
TYPE
Novotec Medical GmbH
BRAND
1
SKU
which was switched on (or off for SHAM conditions) at a frequency of 26 Hz . Subjects were instructed to maintain a half-squat position with their knees flexed at an angle of 60°. Subjects stood with their feet 40 cm apart where the tilting platform reaches peak-to-peak displacement amplitude of 5 mm.
CITATION
POST assessments - (tf)
POST assessments - (tf)
15m
15m
Repete assessment procedure
go to step #8
15m
POST 15 assessments - (tf15)
POST 15 assessments - (tf15)
15m
15m
Repete assessment procedure
15m
POST 30 assessments - (tf30)
POST 30 assessments - (tf30)
15m
15m
Repete assessment procedure go to step #8
15m
Data analysis
Data analysis
A two-way factorial ANOVA was conducted in
Software
R programming language
NAME
The R Foundation
DEVELOPER
SOURCE LINK
with the
Software
afex: Analysis of Factorial Experiments
NAME
Henrik Singmann
DEVELOPER
to compare the main effects of time and trial and the interaction effect of time x trial.
Generalized eta squared (η2) effect sizes were calculated for the ANOVA main and interaction effects.
Software
emmeans: Estimated Marginal Means, aka Least-Squares Means
NAME
Russell Lenth [aut, cre, cph], Henrik Singmann [ctb], Jonathon Love [ctb], Paul Buerkner [ctb], Maxime Herve [ctb]
DEVELOPER
SOURCE LINK
The emmeans package (Lenth et al. 2018) was used to perform follow-up post hoc analysis. Planned comparisons were performed using Sidak corrected linear contrasts comparing. Statistical significance was set at p < 0.05. Standardized changes in the mean of each measure were used to assess magnitudes of effects and were calculated using Cohen’s d and interpreted using thresholds of 0.2, 0.5, 0.8 for small, moderate and large, respectively (Batterham and Hopkins 2006). An effect size of ± 0.2 was considered the smallest worthwhile effect with an effect size of < 0.2 considered to be trivial. The effect was considered unclear if its 95% confidence interval overlapped the thresholds for small positive and small negative effects.
Citations
Step 1
García-Ramos A, Tomazin K, Feriche B, Strojnik V, de la Fuente B, Argüelles-Cienfuegos J, Strumbelj B, Štirn I. The Relationship Between the Lower-Body Muscular Profile and Swimming Start Performance.
https://doi.org/10.1515/hukin-2015-0152Step 1
Tomazin K, Dolenec A, Strojnik V. High-frequency fatigue after alpine slalom skiing.
https://doi.org/10.1007/s00421-008-0685-yStep 8.1
Verges S, Maffiuletti NA, Kerherve H, Decorte N, Wuyam B, Millet GY. Comparison of electrical and magnetic stimulations to assess quadriceps muscle function.
https://doi.org/10.1152/japplphysiol.01051.2007Step 8.1
Allen DG, Lännergren J, Westerblad H. Muscle cell function during prolonged activity: cellular mechanisms of fatigue.
Step 8.2
Verges S, Maffiuletti NA, Kerherve H, Decorte N, Wuyam B, Millet GY. Comparison of electrical and magnetic stimulations to assess quadriceps muscle function.
https://doi.org/10.1152/japplphysiol.01051.2007Step 8.2
Place N, Maffiuletti NA, Martin A, Lepers R. Assessment of the reliability of central and peripheral fatigue after sustained maximal voluntary contraction of the quadriceps muscle.
Step 8.2
Verges S, Maffiuletti NA, Kerherve H, Decorte N, Wuyam B, Millet GY. Comparison of electrical and magnetic stimulations to assess quadriceps muscle function.
https://doi.org/10.1152/japplphysiol.01051.2007Step 8.3
Place N, Maffiuletti NA, Martin A, Lepers R. Assessment of the reliability of central and peripheral fatigue after sustained maximal voluntary contraction of the quadriceps muscle.
Step 9
Ritzmann R, Gollhofer A, Kramer A. The influence of vibration type, frequency, body position and additional load on the neuromuscular activity during whole body vibration.
https://doi.org/10.1007/s00421-012-2402-0