Reliability of spike and turn variables of surface EMG during isometric voluntary contractions of the biceps brachii muscle

2011 ◽  
Vol 21 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Jin Lee ◽  
Min-Ye Jung ◽  
Sung-Hwan Kim
Keyword(s):  
Biceps Brachii ◽  
Surface Emg ◽  
Biceps Brachii Muscle ◽  
Voluntary Contractions

Repeatability of surface EMG variables during voluntary isometric contractions of the biceps brachii muscle

1999 ◽  
Vol 9 (2) ◽  
pp. 105-119 ◽  
Author(s):  
A. Rainoldi ◽  
G. Galardi ◽  
L. Maderna ◽  
G. Comi ◽  
L. Lo Conte ◽  
...  
Keyword(s):  
Biceps Brachii ◽  
Surface Emg ◽  
Isometric Contractions ◽  
Biceps Brachii Muscle

ANALYSIS OF SURFACE EMG SIGNALS UNDER FATIGUE AND NON-FATIGUE CONDITIONS USING B-DISTRIBUTION BASED QUADRATIC TIME FREQUENCY DISTRIBUTION

2015 ◽  
Vol 15 (02) ◽  
pp. 1540028 ◽  
Author(s):  
P. A. KARTHICK ◽  
G. VENUGOPAL ◽  
S. RAMAKRISHNAN
Keyword(s):  
Frequency Distribution ◽  
Biceps Brachii ◽  
Surface Emg ◽  
Median Frequency ◽  
Biceps Brachii Muscle ◽  
Spectral Entropy ◽  
Time Frequency ◽  
Neuromuscular Conditions ◽  
Time Frequency Distribution ◽  
Semg Signals

In this paper, an attempt has been made to analyze surface electromyography (sEMG) signals under non-fatigue and fatigue conditions using time-frequency based features. The sEMG signals are recorded from biceps brachii muscle of 50 healthy volunteers under well-defined protocol. The pre-processed signals are divided into six equal epochs. The first and last segments are considered as non-fatigue and fatigue zones respectively. Further, these signals are subjected to B-distribution based quadratic time-frequency distribution (TFD). Time frequency based features such as instantaneous median frequency (IMDF) and instantaneous mean frequency (IMNF) are extracted. The expression of spectral entropy is modified to obtain instantaneous spectral entropy (ISPEn) from the time-frequency spectrum. The results show that all the extracted features are distinct in both conditions. It is also observed that the values of all features are higher in non-fatigue zone compared to fatigue condition. It appears that this method is useful in analysing various neuromuscular conditions using sEMG signals.

Effects of muscle kinematics on surface EMG amplitude and frequency during fatiguing dynamic contractions

1997 ◽  
Vol 82 (1) ◽  
pp. 144-151 ◽  
Author(s):  
J. R. Potvin
Keyword(s):  
Biceps Brachii ◽  
Elbow Flexion ◽  
Surface Emg ◽  
Mean Power ◽  
Mean Power Frequency ◽  
Emg Amplitude ◽  
Flexion Extension ◽  
Dynamic Contractions ◽  
Power Frequency ◽  
Voluntary Contractions

Potvin, J. R. Effects of muscle kinematics on surface EMG amplitude and frequency during fatiguing dynamic contractions. J. Appl. Physiol. 82(1): 144–151, 1997.—Fifteen male subjects performed a repetitive elbow flexion/extension task with a 7-kg mass until exhaustion. Average joint angle, angular velocity, and biceps brachii surface electromyographic (EMG) amplitude (aEMG) and mean power frequency (MPF) were calculated with each consecutive 250-ms segment of data during the entire trial. Data were separated into concentric or eccentric phases and into seven 20°-ranges from 0 to 140° of elbow flexion. A regression analysis was used to estimate the rested and fatigued aEMG and MPF values. aEMG values were expressed as a percentage of amplitudes from maximum voluntary contractions (MVC). Under rested dynamic conditions, the average concentric aEMG amplitude was 10% MVC higher than average eccentric values. Rested MPF values were similar for concentric and eccentric phases, although values increased ∼20 Hz from the most extended to flexed joint angles. Fatigue resulted in an average increase in concentric and eccentric aEMG of 35 and 10% MVC, respectively. The largest concentric aEMG increases (up to 58% MVC) were observed at higher joint velocities, whereas eccentric increases appeared to be related to decreases in velocity. Fatigue had a similar effect on MPF during both concentric and eccentric phases. Larger MPF decreases were observed at shorter muscle lengths such that values within each angle range were very similar by the end of the trial. It was hypothesized that this finding may reflect a biological minimum in conduction velocity before propagation failure occurs.

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