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.

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.

Muscular endurance and surface electromyogram in isometric and dynamic exercise

1981 ◽  
Vol 51 (1) ◽  
pp. 1-7 ◽  
Author(s):  
M. Hagberg
Keyword(s):  
Maximum Voluntary Contraction ◽  
Isometric Exercise ◽  
Voluntary Contraction ◽  
Dynamic Exercise ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Endurance Time ◽  
Significant Difference ◽  
Power Frequency ◽  
The Mean

In nine male volunteers, the endurance time for sustained isometric exercise (right-angle elbow flexion) and dynamic exercise (continuous concentric and eccentric elbow flexions) was measured at different contraction levels. Intermittent isometric exercises were also performed by four of the subjects in whom surface electromyographic elbow flexor recordings were obtained during the three types of exercise. A rapid decrease of the endurance time was seen at contraction levels above 15–20% of the maximum voluntary contraction for both the sustained isometric and dynamic exercise. There were no significant difference between the regression of the endurance time vs. the contraction level for the sustained isometric exercise and that of the dynamic exercise. However, the endurance time was enhanced in the intermittent isometric exercise compared with the sustained isometric exercise. The development of muscle fatigue was well correlated to change of the myoelectric rootmean-square amplitude and the mean power frequency. Differences in exercise did not significantly affect the relation between the time constant of the mean power frequency decrease and the endurance time.

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.

Measurement and Analysis of Surface Electromyogram and Handgrip Force

2011 ◽  
Vol 225-226 ◽  
pp. 1318-1322
Author(s):  
Dong Mei Hao ◽  
Yan Zhang ◽  
Dong Ye Zhang ◽  
Zheng Wan ◽  
Yi Yang
Keyword(s):  
Voluntary Contraction ◽  
Median Frequency ◽  
Force Level ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Surface Electromyogram ◽  
Static Contraction ◽  
Power Frequency ◽  
Relationship Of ◽  
The Relationship

To investigate the relationship of surface electromyogram (sEMG) and handgrip force, a measurement system was developed. Ten healthy subjects were required to perform a series of static contraction trials by maintaining the force level with maximal voluntary contraction (MVC), 75%MVC, 50%MVC and 25%MVC respectively. Then they sustained MVC as long as possible until fatigue. The handgrip force and sEMG on the forearm muscles were recorded. Root mean square (RMS), mean power frequency (MPF) and median frequency (MF) of the sEMG were calculated with LabVIEW. The results show that RMS increased with force level during voluntary contraction, while MPF and MF shift to lower frequency during fatigue condition. These findings suggested that the designed system can be used to study forearm function.

Gender Comparisons of Mechanomyographic Amplitude and Mean Power Frequency versus Isometric Torque Relationships

2005 ◽  
Vol 21 (1) ◽  
pp. 96-109 ◽  
Author(s):  
Travis W. Beck ◽  
Terry J. Housh ◽  
Glen O. Johnson ◽  
Joseph P. Weir ◽  
Joel T. Cramer ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Maximum Voluntary Contraction ◽  
Fluid Pressure ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Power Frequency ◽  
Isometric Torque ◽  
Muscle Actions ◽  
Best Fit ◽  
Isometric Muscle

This study compared the patterns of mechanomyographic (MMG) amplitude and mean power frequency vs. torque relationships in men and women during isometric muscle actions of the biceps brachii. Seven men (mean age 23.9 ± 3.5 yrs) and 8 women (mean 21.0 ± 1.3 yrs) performed submaximal to maximal isometric muscle actions of the dominant forearm flexors. Following determination of the isometric maximum voluntary contraction (MVC), they randomly performed submaximal step muscle actions in 10% increments from 10% to 90% MVC. Polynomial regression analyses indicated that the MMG amplitude vs. isometric torque relationship for the men was best fit with a cubic model (R2= 0.983), where MMG amplitude increased slightly from 10% to 20% MVC, increased rapidly from 20% to 80% MVC, and plateaued from 80% to 100% MVC. For the women, MMG amplitude increased linearly (r2= 0.949) from 10% to 100% MVC. Linear models also provided the best fit for the MMG mean power frequency vs. isometric torque relationship in both the men (r2= 0.813) and women (r2= 0.578). The results demonstrated gender differences in the MMG amplitude vs. isometric torque relationship, but similar torque-related patterns for MMG mean power frequency. These findings suggested that the plateau in MMG amplitude at high levels of isometric torque production for the biceps brachii in the men, but not the women, may have been due to greater isometric torque, muscle stiffness, and/or intramuscular fluid pressure in the men, rather than to differences in motor unit activation strategies for modulating isometric torque production.

scholarly journals Hand Dominance Effect During right (Accelerator) Throttle Gripping in Riding Simulation

2018 ◽  
Vol 7 (4.27) ◽  
pp. 141
Author(s):  
Nursalbiah Nasir ◽  
Asyraf Hakimi Azmi ◽  
Helmi Rashid
Keyword(s):  
Muscle Activation ◽  
Dominance Effect ◽  
Maximum Voluntary Contraction ◽  
Voluntary Contraction ◽  
Hand Dominance ◽  
Surface Electromyogram ◽  
Flexor Carpi Radialis ◽  
Left Handed ◽  
The Difference

This study investigated the difference in muscle activation of the muscles in right handed (RH) and left handed (LH) participants during riding of motorcycle simulator. Five participants (3 RH and 2 LH) with average age of 24.2±0.447 years old were recruited and they were requested to ride the simulator for certain period of times for three days. Two surface electromyogram (sEMG) electrodes were attached to right flexor carpi radialis (RFCR) and left flexor carpi radialis (LFCR) of the participants forearm. Electromyography (EMG) of flexor carpi radialis (FCR) are measured at both hands during the task. The results showed that muscle activation during first 5 minutes of riding task in day 1 of experiment (percentage of maximum voluntary contraction, %MVC) for RFCR in LH (non-dominant) participants was 97.4% and 87.7% in RH (dominant) participants. Therefore, this result indicates that non-dominant person needs to activate more muscle than RH person during control the accelerator throttle while riding.  

Older adults can maximally activate the biceps brachii muscle by voluntary command

1998 ◽  
Vol 84 (1) ◽  
pp. 284-291 ◽  
Author(s):  
Sophie J. De Serres ◽  
Roger M. Enoka
Keyword(s):  
Older Adults ◽  
Muscle Activation ◽  
Biceps Brachii ◽  
Maximum Voluntary Contraction ◽  
The Elderly ◽  
Voluntary Contraction ◽  
Elderly Subjects ◽  
Biceps Brachii Muscle ◽  
Activation Level ◽  
Voluntary Command

De Serres, Sophie J., and Roger M. Enoka. Older adults can maximally activate the biceps brachii muscle by voluntary command. J. Appl. Physiol. 84(1): 284–291, 1998.—Because some of the decline in strength with age may be explained by an impairment of muscle activation, the purpose of this study was to determine the activation level achieved in biceps brachii by older adults during a maximum voluntary contraction (MVC). This capability was assessed with two superimposition techniques: one calculated the activation level that was achieved during an MVC, and the other provided an estimate of the expected MVC force based on extrapolation with submaximal forces. The activation level in biceps brachii was incomplete (<100%) for the young ( n = 16) and elderly ( n = 16) subjects, with the elderly subjects exhibiting the greater deficit. In contrast, there was no difference between the measured and expected MVC forces for either group of subjects, whether the extrapolation involved a third-order polynomial or linearization of the data. Because of the lower signal-to-noise ratio associated with the measurement of activation level and the greater number of measurements that contributed to the estimate of the expected MVC force, we conclude that the older adults were able to achieve complete activation of the biceps brachii muscle during an MVC.

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