Dependence of the mean power frequency of the electromyogram on muscle force and fibre type

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.

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

BioMed Research International ◽

10.1155/2015/269734 ◽

2015 ◽

Vol 2015 ◽

pp. 1-6 ◽

Cited By ~ 12

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.

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The Temporal Occurrence of the Mean Power Frequency Shift of the Electromyogram During Maximum Prolonged Dynamic and Static Working Cycles

International Journal of Sports Medicine ◽

10.1055/s-2007-1021107 ◽

1994 ◽

Vol 15 (S 1) ◽

pp. S32-S37 ◽

Cited By ~ 13

Author(s):

B. Gerdle ◽

J. Elert

Keyword(s):

Frequency Shift ◽

Mean Power ◽

Mean Power Frequency ◽

Power Frequency ◽

Temporal Occurrence ◽

The Mean

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Muscular endurance and surface electromyogram in isometric and dynamic exercise

Journal of Applied Physiology ◽

10.1152/jappl.1981.51.1.1 ◽

1981 ◽

Vol 51 (1) ◽

pp. 1-7 ◽

Cited By ~ 175

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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Postural sway following inversion sprain of the ankle

Journal of the American Podiatric Medical Association ◽

10.7547/87507315-81-5-243 ◽

1991 ◽

Vol 81 (5) ◽

pp. 243-247 ◽

Cited By ~ 67

Author(s):

MW Cornwall ◽

P Murrell

Keyword(s):

Ankle Sprain ◽

Postural Sway ◽

Center Of Pressure ◽

Control Group ◽

Mean Power ◽

Mean Power Frequency ◽

Linear Distance ◽

History Of ◽

Power Frequency ◽

The Mean

The single-limb sway of 20 individuals with a history of unilateral inversion ankle sprain was compared to that of a control group of 30 individuals without a history of ankle sprain. Using a force platform to obtain center-of-pressure data, the linear distance traveled (mm) and the mean power frequency, (Hz) of postural sway were calculated for each subject. The results of this study showed that postural sway amplitude was significantly greater in the injured group than in the control group. Contrary to previous investigations, this study indicates that individuals with a history of inversion ankle sprain are less stable in single-limb stance compared to a noninjured control group. This decreased stability is evident as much as 2 years following the injury.

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