Is the VO2 slow component in heavy arm-cranking exercise associated with recruitment of type II muscle fibers as assessed by an increase in surface EMG?

2006 ◽  
Vol 31 (4) ◽  
pp. 414-422 ◽  
Author(s):  
Sylvain Bernasconi ◽  
Nicolas Tordi ◽  
Stéphane Perrey ◽  
Bernard Parratte ◽  
Guy Monnier
Keyword(s):  
Ventilatory Threshold ◽  
Biceps Brachii ◽  
Slow Component ◽  
Muscle Fibers ◽  
Exponential Model ◽  
Type Ii ◽  
Triceps Brachii ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Arm Cranking

The recruitment of additional type II muscle fibers is one mechanism often suggested to be responsible for the slow component of oxygen uptake (VO2 SC). We hypothesized that surface electromyogram (EMG) of the biceps brachii, triceps brachii, anterior deltoid, and infraspinatus muscles could be related to the VO2 SC amplitude during arm-cranking exercises above ventilatory threshold (VT). Eight healthy subjects performed transitions from rest to 6-min heavy exercise at a constant power output of approximately 40% between VT and peak VO2. A 2-component exponential model was used to fit the VO2 response. EMG were recorded the last 15 s of each minute to obtain root mean square (RMS) and mean power frequency (MPF). Mean EMG responses for RMS and MPF were calculated by averaging EMG responses of the 4 muscles. The VO2 SC amplitude was of 530 ± 166 mL/min and occurred after 134 ± 31 s of exercise onset. Significant correlations were found for most of the subjects between EMG parameters and the VO2 SC amplitude as determined between the 2nd and the 6th minute. For all muscles, RMS values significantly increased over time during the VO2 SC, whereas MPF decreased significantly. These results suggest a relation between the recruitment of additional type II muscle fibers and the VO2 SC in arm-cranking exercises.

Intramuscular and surface electromyogram changes during muscle fatigue

1986 ◽  
Vol 60 (4) ◽  
pp. 1179-1185 ◽  
Author(s):  
T. Moritani ◽  
M. Muro ◽  
A. Nagata
Keyword(s):  
Muscle Fatigue ◽  
Biceps Brachii ◽  
Surface Emg ◽  
Firing Frequency ◽  
Voluntary Contraction ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Surface Electromyogram ◽  
Spike Amplitude ◽  
Frequency Power

Twelve male subjects were tested to determine the effects of motor unit (MU) recruitment and firing frequency on the surface electromyogram (EMG) frequency power spectra during sustained maximal voluntary contraction (MVC) and 50% MVC of the biceps brachii muscle. Both the intramuscular MU spikes and surface EMG were recorded simultaneously and analyzed by means of a computer-aided intramuscular spike amplitude-frequency histogram and frequency power spectral analysis, respectively. Results indicated that both mean power frequency (MPF) and amplitude (rmsEMG) of the surface EMG fell significantly (P less than 0.001) together with a progressive reduction in MU spike amplitude and firing frequency during sustained MVC. During 50% MVC there was a significant decline in MPF (P less than 0.001), but this decline was accompanied by a significant increase in rmsEMG (P less than 0.001) and a progressive MU recruitment as evidenced by an increased number of MUs with relatively large spike amplitude. Our data suggest that the surface EMG amplitude could better represent the underlying MU activity during muscle fatigue and the frequency powers spectral shift may or may not reflect changes in MU recruitment and rate-coding patterns.

Is the V˙o 2 slow component dependent on progressive recruitment of fast-twitch fibers in trained runners?

2001 ◽  
Vol 90 (6) ◽  
pp. 2212-2220 ◽  
Author(s):  
F. Borrani ◽  
R. Candau ◽  
G. Y. Millet ◽  
S. Perrey ◽  
J. Fuchslocher ◽  
...  
Keyword(s):  
Slow Component ◽  
Vastus Lateralis ◽  
Classical Model ◽  
Average Frequency ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Lower Limb Muscles ◽  
Motor Unit Discharge ◽  
Gastrocnemius Muscles ◽  
Fast Twitch

The goal of this study was to use spectral analysis of EMG data to test the hypothesis that the O2 uptake (V˙o 2) slow component is due to a recruitment of fast fibers. Thirteen runners carried out a treadmill test with a constant speed, corresponding to 95% of the velocity associated with maximal V˙o 2. TheV˙o 2 response was fit with the classical model including three exponential functions. Electrical activity of six lower limb muscles (vastus lateralis, soleus, and gastrocnemius of both sides) was measured using electromyogram surface electrodes. Mean power frequency (MPF) was used to study the kinetics of the electromyogram discharge frequency. Three main results were observed: 1) a common pattern of the MPF kinetics in the six muscles studied was noted; 2) MPF decreased in the first part of the exercise, followed by an increase for all the muscles studied, but only the vastus lateralis, and gastrocnemius muscles of both sides increased significantly ( P < 0.05); and 3) the beginning of the MPF increase of the four muscles mentioned above corresponded with the beginning of the slow component. Our results suggest a progression in the average frequency of the motor unit discharge toward the high frequencies, which coheres with the hypothesis of the progressive recruitment of fast-twitch fibers during the V˙o 2 slow component. However, this interpretation must be taken with caution because MPF is the result of a balance between several phenomena.

Effect of Arm Cranking Direction on EMG, Kinematic, and Oxygen Consumption Responses

2004 ◽  
Vol 20 (2) ◽  
pp. 129-143 ◽  
Author(s):  
Eadric Bressel ◽  
Gary D. Heise
Keyword(s):  
Oxygen Consumption ◽  
Muscle Activity ◽  
Biceps Brachii ◽  
Emg Activity ◽  
Half Cycle ◽  
Wrist Flexion ◽  
Triceps Brachii ◽  
Arm Cranking ◽  
Video Images ◽  
Consumption Data

The purpose of this study was to compare muscle activity, kinematic, and oxygen consumption characteristics between forward and reverse arm cranking. Twenty able-bodied men performed 5-min exercise bouts of forward and reverse arm cranking while electromyographic (EMG), kinematic, and oxygen consumption data were collected. EMG activity of biceps brachii, triceps brachii, deltoid, and infraspinatus muscles were recorded and analyzed to reflect on-time durations and amplitudes for each half-cycle (first 180° and second 180° of crank cycle). Kinematic data were quantified from digitization of video images, and oxygen consumption was calculated from expired gases. Dependent measures were analyzed with a MANOVA and follow-up univariate procedures; alpha was set at .01. The biceps brachii, deltoid, and infraspinatus muscles displayed greater on-time durations and amplitudes for select half-cycles of reverse arm cranking compared to forward arm cranking (p< 0.01). Peak wrist flexion was 9% less in reverse arm cranking (p< 0.01), and oxygen consumption values did not differ between conditions (p= 0.25). Although there were no differences in oxygen consumption and only minor differences kinematically, reverse arm cranking requires greater muscle activity from the biceps brachii, deltoid, and infraspinatus muscles. These results may allow clinicians to more effectively choose an arm cranking direction that either minimizes or maximizes upper extremity muscle activity depending on the treatment objectives.

Features for muscle fatigue computed from electromyogram and mechanomyogram: A new one

2016 ◽  
Vol 230 (12) ◽  
pp. 1096-1105 ◽  
Author(s):  
Şükrü Okkesim ◽  
Kezban Coşkun
Keyword(s):  
Muscle Fatigue ◽  
Frequency Ratio ◽  
Biceps Brachii ◽  
Median Frequency ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Power Frequency ◽  
Ratio Change ◽  
The Mean ◽  
New Feature

Muscle fatigue produces negative effects in the performance and it may lead to a muscle failure. This problem makes the quantitative grading of muscle fatigue a necessity in ergonomic and physiological research. Moreover, the quantitative grading of muscle fatigue is needed to increase work and sport productivity and prevent several accidents that result from muscle fatigue. Even though there are many studies for this aim, there is no quantitative criterion for the evaluation of muscle fatigue. The main reason is that muscle fatigue is a complex physiological situation that is dependent on several parameters. Our aim in this study is to present a new feature to evaluate muscle fatigue and prove the reliability of the new feature by making correlation analyses between this with other features. For this aim, electromyography and mechanomyography signals were simultaneously recorded from the biceps brachii and triceps brachii muscles during the isometric and isotonic contractions of 60 healthy volunteers (30 females, 30 males). The mean power frequency and median frequency, which are used in the literature, were compared to the frequency ratio change, the new measure; correlations between the frequency ratio change and the mean power frequency and median frequency were analysed. There was a high correlation between the features, and frequency ratio change can be used to quantitatively evaluate muscle fatigue.

scholarly journals Comparison of Endurance Time Prediction of Biceps Brachii Using Logarithmic Parameters of a Surface Electromyogram during Low-Moderate Level Isotonic Contractions

2021 ◽  
Vol 11 (6) ◽  
pp. 2861
Author(s):  
Chang-ok Cho ◽  
Jin-Hyoung Jeong ◽  
Yun-jeong Kim ◽  
Jee Hun Jang ◽  
Sang-Sik Lee ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Endurance Capacity ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Spectral Parameters ◽  
Endurance Time ◽  
Surface Electromyogram ◽  
Isotonic Contractions

At relatively low effort level tasks, surface electromyogram (sEMG) spectral parameters have demonstrated an inconsistent ability to monitor localized muscle fatigue and predict endurance capacity. The main purpose of this study was to assess the potential of the endurance time (Tend) prediction using logarithmic parameters compared to raw data. Ten healthy subjects performed five sets of voluntary isotonic contractions until their exhaustion at 20% of their maximum voluntary contraction (MVC) level. We extracted five sEMG spectral parameters namely the power in the low frequency band (LFB), the mean power frequency (MPF), the high-to-low ratio between two frequency bands (H/L-FB), the Dimitrov spectral index (DSI), and the high-to-low ratio between two spectral moments (H/L-SM), and then converted them to logarithms. Changes in these ten parameters were monitored using area ratio and linear regressive slope as statistical predictors and estimating from onset at every 10% of Tend. Significant correlations (r > 0.5) were found between log(Tend) and the linear regressive slopes in the logarithmic H/L-SM at every 10% of Tend. In conclusion, logarithmic parameters can be used to describe changes in the fatigue content of sEMG and can be employed as a better predictor of Tend in comparison to the raw parameters.

Muscle Strength Assessment from the EMG Frequency Spectrum

1987 ◽  
Vol 31 (3) ◽  
pp. 310-314 ◽  
Author(s):  
Eui S. Jung
Keyword(s):  
Biceps Brachii ◽  
Muscle Tension ◽  
Maximum Voluntary Contraction ◽  
Power Spectra ◽  
Voluntary Contraction ◽  
The Other ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Strength Assessment ◽  
The Right

Assessment of a worker's strength is of great interest when evaluating the worker's ability to safely perform a job. Many previous studies have shown that surface electromyogram EMG amplitudes correlate well with muscle force. The present study furthered this concept by using EMG power spectra to achieve a quantified representation of true strength capability. Two groups of male subjects performed isometric elbow flexions while EMG was obtained from the right belly of biceps brachii. One group exercised their arms regularly while the other not. Six different levels of graded maximum voluntary contraction (%MVC) were selected to examine the relations between muscle tension and the mean power frequency (MPF) resulting from EMG power spectra. Resultant MPF's ranged between 50Hz and 70Hz in agreement with previous research results. Two-way ANOVA showed that, in the trained group, a significant increase in the MPF was found at near maximum contractions, whereas the other group failed to show any difference. Further analysis revealed that this increase in MPF was mainly caused by the power increase in the higher bandwidth (70—100Hz). A significant variation between subjects in both groups was also observed.

V˙o 2 kinetics in heavy exercise is not altered by prior exercise with a different muscle group

2002 ◽  
Vol 92 (6) ◽  
pp. 2467-2474 ◽  
Author(s):  
Yoshiyuki Fukuba ◽  
Naoyuki Hayashi ◽  
Shunsaku Koga ◽  
Takayoshi Yoshida
Keyword(s):  
Near Infrared ◽  
Slow Component ◽  
Exponential Model ◽  
Muscle Group ◽  
Heavy Exercise ◽  
Arm Cranking ◽  
Warm Up ◽  
Leg Muscles ◽  
Leg Cycling ◽  
Lactic Acidemia

We examined whether lactic acidemia-induced hyperemia at the onset of high-intensity leg exercise contributed to the speeding of pulmonary O2 uptake (V˙o 2) after prior heavy exercise of the same muscle group or a different muscle group (i.e., arm). Six healthy male subjects performed two protocols that consisted of two consecutive 6-min exercise bouts separated by a 6-min baseline at 0 W: 1) both bouts of heavy (work rate: 50% of lactate threshold to maximal V˙o 2) leg cycling (L1-ex to L2-ex) and 2) heavy arm cranking followed by identical heavy leg cycling bout (A1-ex to A2-ex). Blood lactate concentrations before L1-ex, L2-ex, and A2-ex averaged 1.7 ± 0.3, 5.6 ± 0.9, and 6.7 ± 1.4 meq/l, respectively. An “effective” time constant (τ) of V˙o 2 with the use of the monoexponential model in L2-ex (τ: 36.8 ± 4.3 s) was significantly faster than that in L1-ex (τ: 52.3 ± 8.2 s). Warm-up arm cranking did not facilitate theV˙o 2 kinetics for the following A2-ex [τ: 51.7 ± 9.7 s]. The double-exponential model revealed no significant change of primary τ (phase II)V˙o 2 kinetics. Instead, the speeding seen in the effective τ during L2-ex was mainly due to a reduction of theV˙o 2 slow component. Near-infrared spectroscopy indicated that the degree of hyperemia in working leg muscles was significantly higher at the onset of L2-ex than A2-ex. In conclusion, facilitation of V˙o 2 kinetics during heavy exercise preceded by an intense warm-up exercise was caused principally by a reduction in the slow component, and it appears unlikely that this could be ascribed exclusively to systemic lactic acidosis.

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