Electromyographic Studies of Muscular Fatigue in Man

Cobb, Stanley; Forbes, Alexander

doi:10.1152/ajplegacy.1923.65.2.234

Cited by 80 publications

(37 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The results in the current study are consistent with prior reports showing an increase in the surface EMG amplitude during fatiguing contractions (Cobb and Forbes 1923;Edwards and Lippold 1956;Fuglevand et al 1993;Lind and Petrofsky 1979;Rudroff et al 2008) and the absence of an increase in coactivation of the triceps brachii muscle (cf. Levenez et al 2005;Maluf and Enoka 2005).…”

Section: Discussionsupporting

confidence: 93%

“…electromyography; monopolar signals; muscle fatigue; principal component analysis; cluster algorithm; motor control THE EFFECTS OF FATIGUE EMERGE from the beginning of sustained submaximal muscle contractions (Mosso 1906) as indicated by the increase of the amplitude of the surface electromyogram (EMG) needed to sustain the required force (Bigland and Lippold 1954;Cobb and Forbes 1923;De Luca 1984;Edwards and Lippold 1956). Because the motor units recruited from the beginning of a fatiguing contraction exhibit a progressive decrease in discharge rate (Mottram et al 2005;Rudroff et al 2011), the increase in EMG amplitude is generally attributed to the recruitment of additional motor units Gandevia 2001) but can also be influenced by changes in the conduction velocity of motor unit action potentials and the synchronization of motor unit discharge times (Arabadzhiev et al 2010;Yao et al 2000).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Increase in heterogeneity of biceps brachii activation during isometric submaximal fatiguing contractions: a multichannel surface EMG study

Staudenmann

Dieën

Stegeman

et al. 2014

Journal of Neurophysiology

View full text Add to dashboard Cite

Staudenmann D, van Dieën JH, Stegeman DF, Enoka RM. Increase in heterogeneity of biceps brachii activation during isometric submaximal fatiguing contractions: a multichannel surface EMG study. J Neurophysiol 111: 984 -990, 2014. First published December 11, 2013 doi:10.1152/jn.00354.2013.-The effects of fatigue emerge from the beginning of sustained submaximal contractions, as shown by an increase in the amplitude of the surface electromyogram (EMG). The increase in EMG amplitude is attributed to an augmentation of the excitatory drive to the motor neuron pool that, more importantly than increasing discharge rates, recruits additional motor units for the contraction. The aim of this study was to determine whether the spatiotemporal distribution of biceps brachii (BB) activity becomes more or less heterogeneous during a fatiguing isometric contraction sustained at a submaximal target force. Multiple electrodes were attached over the entire BB muscle, and principal component analysis (PCA) was used to extract the representative information from multiple monopolar EMG channels. The development of heterogeneity during the fatiguing contraction was quantified by applying a cluster algorithm on the PCA-processed EMG amplitudes. As shown previously, the overall EMG amplitude increased during the sustained contraction, whereas there was no change in coactivation of triceps brachii. However, EMG amplitude did not increase in all channels and even decreased in some. The change in spatial distribution of muscle activity varied across subjects. As found in other studies, the spatial distribution of EMG activity changed during the sustained contraction, but the grouping and size of the clusters did not change. This study showed for the first time that muscle activation became more heterogeneous during a sustained contraction, presumably due to a decrease in the strength of common inputs with the recruitment of additional motor units.

show abstract

Section: Discussionsupporting

confidence: 93%

mentioning

confidence: 99%

Increase in heterogeneity of biceps brachii activation during isometric submaximal fatiguing contractions: a multichannel surface EMG study

Staudenmann

Dieën

Stegeman

et al. 2014

Journal of Neurophysiology

View full text Add to dashboard Cite

show abstract

“…Since the historic work of Piper (I], the frequencies of the ME signal have been known to decrease during a sustained contrac tion. Cobb and Forbes [2] noted this shift in the frequency components with fatigue, but also observed a consistent in crease in amplitude of the ME signals recorded with surface electrodes. Many other investigators have noted an increase in ME signal amplitude [3]- [11].…”

Section: Introductionsupporting

confidence: 54%

Frequency Parameters of the Myoelectric Signal as a Measure of Muscle Conduction Velocity

Stulen

Luca

1981

IEEE Trans. Biomed. Eng.

495

278

View full text Add to dashboard Cite

Abstract-During a sustained muscle contraction, the lpectlUm of the myoelectric lignal is known to undergo compression as a function of time. Previous investigators have shown that the frequency compres sion is related to the decreasing conduction velocity of the muscle fi bers. It is proposed that the frequency compression may be tracked by obtaining a continuous estimate of a characteristic frequency of the spectrum, such as the mean and median, or the ratioof low-frequency components to high-frequency components of the speetrum. A theo retical analysis was performed to investigate the restrictions in estimat ing the three parameters, as well as their sensitivity to the conduction velocity. The ratio parameter was found to be mostsensitive to con duction velocity, but was the least reliable of the three. The median frequency was the least sensitive to noise. Therefore, from a theoretical point of view, the median frequency is the preferred parameter. A technique is described which determines an unbiased consistent esti mate of the median frequency. The technique may be readily imple mented in analog hardware.

show abstract

“…The results at the lumbar levels agreed with those of Chapman & Troup (1970) in their study of normal individuals who were loaded in the upright posture. Several other investigators, however, have found an increase in the signal amplitude during sustained muscle contractions of arm and hand muscles (Bigland & Lippold 1954, Cobb & Forbes 1923, Edwards & Lippold 1956). …”

Section: Discussionmentioning

confidence: 95%

Electromyography of the paravertebral muscles in idiopathic scoliosis: Measurements of amplitude and spectral changes under load

Zetterberg

Björk

Örtengren

et al. 1984

Acta Orthopaedica Scandinavica

View full text Add to dashboard Cite

Electromyographic Studies of Muscular Fatigue in Man

Cited by 80 publications

References 0 publications

Increase in heterogeneity of biceps brachii activation during isometric submaximal fatiguing contractions: a multichannel surface EMG study

Increase in heterogeneity of biceps brachii activation during isometric submaximal fatiguing contractions: a multichannel surface EMG study

Frequency Parameters of the Myoelectric Signal as a Measure of Muscle Conduction Velocity

Electromyography of the paravertebral muscles in idiopathic scoliosis: Measurements of amplitude and spectral changes under load

Contact Info

Product

Resources

About