Surface electromyographic alterations of the knee extensor musculature based on contraction intensity and velocity

Croce, Ronald V.; Miller, John P.; Smith, Wayne; Horvat, Michael

doi:10.3233/ies-2012-0452

Cited by 2 publications

(25 citation statements)

References 45 publications

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“…found spectral frequencies increased only in the VL in men and not in women, and not in RF and VM, which they attributed to the VL in men having greater type II fiber content. The results from our investigation concur most with the results of Croce et al . and Gerdle et al ., who reported that QF spectral frequencies are positively torque‐dependent, with the RF displaying highest values.…”

Section: Discussionsupporting

confidence: 92%

“…all reported no significant relationship between spectral frequencies and torque across RF, VL, and VM muscles; VM and VL muscles; and VM muscle, respectively. On the other hand, Croce et al ., Gerdle et al ., Karlsson and Gerdle, and Gerdle and Karlsson all reported positive, torque‐dependent associations between frequency content and increasing torque in the superficial QF muscles. Pincivero et al .…”

Section: Discussionmentioning

confidence: 93%

“…and Gerdle et al ., who reported that QF spectral frequencies are positively torque‐dependent, with the RF displaying highest values. For example, Croce et al . investigated the effect of contraction intensity and movement velocity on SEMG median frequency, as measured by STFT, and found a positive relationship between contraction intensity and SEMG MDF , with greater SEMG MDF values for RF than the VM across all contraction intensities.…”

Section: Discussionmentioning

confidence: 99%

“…During submaximal tests, subjects viewed a moment–time curve of their moment output and were given verbal feedback to reach, but not exceed, the percent of maximum being tested. A submaximal test trial was repeated if the moment value produced was not within ±5% of desired moment value and not reached within 6 repetitions …”

Section: Methodsmentioning

confidence: 99%

“…Surface electromyography (SEMG) is a noninvasive procedure for investigating the degree to which these 2 mechanisms are involved in controlling voluntary muscular contractions. SEMG produces a time waveform with an amplitude and frequency content that provides information about muscle functioning . Myoelectric signal amplitude (SEMG AMP ) is used as an indirect measure of overall muscle activity and of muscle contraction force.…”

mentioning

confidence: 99%

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Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity

et al. 2014

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

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Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity

et al. 2014

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Wavelet and principal component analysis of electromyographic activity and slow component of oxygen uptake during heavy and severe cycling exercise

Zhou

et al. 2020

Appl. Physiol. Nutr. Metab.

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The aim of the study was to investigate whether the slow component of oxygen uptake was concurrent with the recruitment of large α-motoneuron muscle fibres by using wavelet and principal component analysis (PCA) of electromyography (EMG) during heavy and severe cycling exercise. Eleven male subjects participated in the study. After establishing each subject’s maximum value of oxygen uptake through an incremental test on the cycle ergometer, the subjects performed 6-min cycling tests at heavy and severe intensity. EMG signals were collected from rectus femoris, biceps femoris long head, tibialis anterior, and medial gastrocnemius and processed by combined use of wavelet and PCA analysis. The time delays to the onset of slow component occurred significantly earlier during severe (105.22 ± 5.45 s) compared with during heavy (138.78 ± 15.09 s) exercise. ANOVA with repeated measures showed that for all muscles tested, the angle θ formed by the first and second principal components decreased significantly between time windows during heavy and severe exercise. However, significant increases of EMG mean power frequency (MPF) were found only during heavy exercise. Our results show the concurrence of the oxygen uptake slow component with the additional recruitment of muscle fibres, presumably less efficient large α-motoneuron fibres. Novelty The expected rise in MPF may be offset by muscle fatigue occurring in the later time windows of the slow component during severe exercise. The gradual shift to higher EMG frequencies throughout the slow-component phase was reflected in the progressive and significant decrease of angle θ.

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Surface electromyographic alterations of the knee extensor musculature based on contraction intensity and velocity

Cited by 2 publications

References 45 publications

Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity

Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity

Wavelet and principal component analysis of electromyographic activity and slow component of oxygen uptake during heavy and severe cycling exercise

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