Muscle Tonus in Postural Muscles

Vries, Herbert A. De

doi:10.1097/00002060-196512000-00001

Cited by 10 publications

(3 citation statements)

References 3 publications

(5 reference statements)

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“…In contrast, lower gap values were observed in lower limb musculature for both the discrete task and daily activity. Weight-bearing locomotor activities are key contributors to total body energy expenditure for sedentary lifestyles [28], whereas sitting and quiet standing do not effectively activate the hamstring or vastus muscles [29,30]. Subjects in the present study reported mobility levels (moving, standing, stairs), that were generally higher than sedentary scores, suggesting the discrepancy between our findings and prior studies [13,27] was due to more active subjects in the present study.…”

Section: Muscle-related Differencescontrasting

confidence: 95%

Age- and sex-related differences for electromyography gaps during daily activity and a discrete task

2011

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Section: Muscle-related Differencescontrasting

confidence: 95%

Age- and sex-related differences for electromyography gaps during daily activity and a discrete task

2011

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“…force produced) to incrementally increasing electrical stimulations (Lucas 1905, Eccles and Sherrington 1930, Rosenblueth et al 1941, Loofbourrow 1948, while later studies recorded the electrical output (i.e. EMG) of the muscle during incremental voluntary contractions (Inman et al 1952, Lippold 1952, de Vries 1965. The relationship between skeletal muscle electrical activity and force has been shown to be highly linear and positive (Lippold 1952, de Vries 1965, de Vries 1968, Milner-Brown and Stein 1975, Moritani and de Vries 1978.…”

Section: Importance Of the Emg Amplitude Versus Force Relationshipmentioning

confidence: 99%

“…EMG) of the muscle during incremental voluntary contractions (Inman et al 1952, Lippold 1952, de Vries 1965. The relationship between skeletal muscle electrical activity and force has been shown to be highly linear and positive (Lippold 1952, de Vries 1965, de Vries 1968, Milner-Brown and Stein 1975, Moritani and de Vries 1978. Multiple studies have suggested that decreases in the linear slope coefficient (a measure of the efficiency of electrical activity) between EMG amplitude and force may be indicative of increases in skeletal muscle mass (Fischer and Merhautova 1961, de Vries 1968, Moritani and de Vries 1979.…”

Section: Importance Of the Emg Amplitude Versus Force Relationshipmentioning

confidence: 99%

Comparison of methods for removing electromagnetic noise from electromyographic signals

DeFreitas

Beck²,

Stock³

2012

Physiol. Meas.

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The purpose of this investigation was to compare three different methods of removing noise from monopolar electromyographic (EMG) signals: (a) electrical shielding with a Faraday cage, (b) denoising with a digital notch-filter and (c) applying a bipolar differentiation with another monopolar EMG signal. Ten men and ten women (mean age = 24.0 years) performed isometric muscle actions of the leg extensors at 10-100% of their maximal voluntary contraction on two separate occasions. One trial was performed inside a Faraday tent (a flexible Faraday cage made from conductive material), and the other was performed outside the Faraday tent. The EMG signals collected outside the Faraday tent were analyzed three separate ways: as a raw signal, as a bipolar signal, and as a signal digitally notch filtered to remove 60 Hz noise and its harmonics. The signal-to-noise ratios were greatest after notch-filtering (range: 3.0-33.8), and lowest for the bipolar arrangement (1.6-10.2). Linear slope coefficients for the EMG amplitude versus force relationship were also used to compare the methods of noise removal. The results showed that a bipolar arrangement had a significantly lower linear slope coefficient when compared to the three other conditions (raw, notch and tent). These results suggested that an appropriately filtered monopolar EMG signal can be useful in situations that require a large pick-up area. Furthermore, although it is helpful, a Faraday tent (or cage) is not required to achieve an appropriate signal-to-noise ratio, as long as the correct filters are applied.

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The role of the antigravity musculature during quiet standing in man

Soames

Atha

1981

Europ. J. Appl. Physiol.

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The view that postural regulation is achieved by controlling the destabilising effects of gravity through myotatic reflex activity was examined using surface electromyography. Forty seconds of recordings were made of myograms from eighteen muscles in each of a sample of nine young adults. It was observed that antigravity muscular activity in standing is generally low and often absent, and that the myograms from the muscles of the right and left sides of the body differed appreciably, the two sides rarely working together. Some sudden and united bursts of antigravity muscle activity could be observed. These might well have been stretch reflex induced, but they were transient and rare. It is concluded that the view that postural control in quiet standing is continuously mediated in a simple way by stretch reflex mechanisms is probably not valid, and that other mechanisms for controlling posture remain to be identified.

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Muscle Tonus in Postural Muscles

Abstract: The author wishes t o express his appreciation to Mr. Barrett B. Weeltes for technical assistance. 275(1) 200 cps.

Cited by 10 publications

References 3 publications

Age- and sex-related differences for electromyography gaps during daily activity and a discrete task

Age- and sex-related differences for electromyography gaps during daily activity and a discrete task

Comparison of methods for removing electromagnetic noise from electromyographic signals

The role of the antigravity musculature during quiet standing in man

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