The Measurement of Sensitivity of Numerical Parameters in Quantification of Local Muscle Fatigue

1998 ◽  
Vol 42 (12) ◽  
pp. 936-939 ◽  
Author(s):  
Jung-Yong Kim ◽  
Myung-Chul Jung
Keyword(s):  
Muscle Fatigue ◽  
Voluntary Contraction ◽  
Erector Spinae ◽  
Superior Performance ◽  
Median Frequency ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Zero Crossing ◽  
Power Frequency ◽  
Local Muscle Fatigue

In order to find the most sensitive Electromyographic (EMG) parameter in quantification of local muscle fatigue (LMF), the first coefficient of Autoregression Model (ARC), Zero Crossing Rate (ZCR), Mean Power Frequency (MPF), Median Frequency (MF) have been analyzed and compared with each other in this study. Ten healthy male subjects participated in the experiment, and EMG signals were collected from the erector spinae muscle continuously for twenty seconds while subjects were isometrically extending their trunk. Various exertion levels such as 15%, 30%, 45%, 60%, and 75% of Maximal Voluntary Contraction (MVC) were also applied to the subjects. As results, ARC was found to be the most sensitive parameter at the level of 15% to 60% of MVC in terms of both slope and R2 value of regression model. On the other hand, MPF and ARC showed the highest R2 value at 60% and 75% level of MVC although MPF scored the lowest slope value at those levels. Moreover, MPF showed a superior performance to MF at 30% to 75% level of MVC.

Interpretation of EMG spectral alterations and alteration indexes at sustained contraction

1992 ◽  
Vol 73 (4) ◽  
pp. 1211-1217 ◽  
Author(s):  
G. M. Hagg
Keyword(s):  
Power Spectrum ◽  
Action Potential ◽  
Median Frequency ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Zero Crossing ◽  
Factors Affecting ◽  
Fatigue Development ◽  
Substantial Progress ◽  
Power Frequency

Alterations of the electromyographic power spectrum have been studied extensively to assess fatigue development in the neuromuscular system. Usually, a data reduction has been applied to create an index based on the mean power frequency or the median frequency. The physiological origin of the spectrum alterations has been (and to some extent still is) incompletely known. However, during the 1980s, substantial progress has been made in this field. The factors affecting the electromyographic power spectrum discussed in this review are action potential velocity decrease, firing statistics alterations, action potential modification, muscle temperature, additional recruitment at fatigue, and force level. Their impact on three commonly used fatigue indexes, mean power frequency, median frequency, and zero crossing rate, is also reviewed.

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.

EMG Power Spectrum Analysis to Assess Muscle Fatigue under Isometric Endurance Work

1983 ◽  
Vol 27 (5) ◽  
pp. 372-373
Author(s):  
S. Deivanayagam ◽  
T. W. Carmichael
Keyword(s):  
Power Spectrum ◽  
Muscle Fatigue ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Straight Line ◽  
Power Frequency ◽  
Emg Power Spectrum ◽  
Spectrum Shift ◽  
Local Muscle Fatigue ◽  
Isometric Work

A research experimental study was conducted to make use of EMG power spectrum shift to assess the local muscle fatigue induced by isometric work. Sixteen male volunteer subjects participated in the study. The results indicate that the shift in mean power frequency (MPF) and the time constant of the straight line relationship between in (MPF) and elapsed time are reliable objective measures of local muscular fatigue.

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.

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.

Surface EMG Based Muscle Fatigue Evaluation on Neck-Shoulder Muscles while Using Single-Monitor Arm

2016 ◽  
Vol 29 ◽  
pp. 61-67 ◽  
Author(s):  
Yan Hao Shao ◽  
Yan Song Zhou ◽  
Yan Zhang ◽  
Yao Dong Gu ◽  
Gusztáv Fekete ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Surface Emg ◽  
Test Surface ◽  
Significant Shift ◽  
Median Frequency ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Shoulder Muscles ◽  
Shoulder Region ◽  
Fatigue Evaluation

The median frequency (MF) and mean power frequency (MPF) have been confirmed as reliable indicators of muscle fatigue during sustained contractions. The purpose of this study was to explore whether single-monitor arm could release muscle fatigue in neck-shoulder region while maintaining a prolonged seated posture viewing computer screen by measuring MF and MPF. Ten male healthy university students volunteered to participate in the test. Surface electromyography of splenius capitis (SC) and trapezius (TR) were recorded. Each subject performed normal text editing tasks or video watching activities for 120 minutes with different monitor arm positions (Fixed, moving downward and moving upward). Results showed that the MPF of SC and TR had significant decreased trend as monitor arm at fixed position. As monitor arm moving upward, the MF and MPF of both muscles decreased significantly with time and the MF showed the lowest decline rate during the entire testing process. No significant shift of MF and MPF were observed as monitor arm moving downward. Findings of this study may have important implications for people who use computer intensively to release neck-shoulder muscle fatigue.

scholarly journals Muscle Fatigue in the Temporal and Masseter Muscles in Patients with Temporomandibular Dysfunction

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Krzysztof Woźniak ◽  
Mariusz Lipski ◽  
Damian Lichota ◽  
Liliana Szyszka-Sommerfeld
Keyword(s):  
Muscle Fatigue ◽  
Isometric Contraction ◽  
Temporomandibular Disorders ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Temporomandibular Dysfunction ◽  
Maximum Effort ◽  
Power Frequency ◽  
The Mean ◽  
Masseter Muscles

The aim of this study is to evaluate muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction (TMD). Two hundred volunteers aged 19.3 to 27.8 years (mean 21.50, SD 0.97) participated in this study. Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany). Muscle fatigue was evaluated on the basis of a maximum effort test. The test was performed during a 10-second maximum isometric contraction (MVC) of the jaws. An analysis of changes in the mean power frequency of the two pairs of temporal and masseter muscles (MPF%) revealed significant differences in the groups of patients with varying degrees of temporomandibular disorders according to Di (P<0.0000). The study showed an increase in the muscle fatigue of the temporal and masseter muscles correlated with the intensity of temporomandibular dysfunction symptoms in patients. The use of surface electromyography in assessing muscle fatigue is an excellent diagnostic tool for identifying patients with temporomandibular dysfunction.

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.

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