Action Potential Paraneters in Normal Human Musele and their Physiological Determinants

Buchthal, Fritz; Pinell, Patrice; Rosenfalck, Poul

doi:10.1111/j.1748-1716.1954.tb01168.x

Cited by 218 publications

(53 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We found 29-36%, whereas Buchthal et al 5 gave an average of 3.4% in adults. There are less diphasic potentials, in our subjects 7-18%, against 45% in adults according to Buchthal et al6. There is no relationship between the degree of the senile modi fications of the parameters of the muscular action potential and the age between 73 to 89; nor is there any relationship between the professional and physical activity of the subject and his EMG characteristics.…”

Section: Resultscontrasting

confidence: 46%

Electromyography on Aging

Mitolo¹

1968

Gerontology

View full text Add to dashboard Cite

Section: Resultscontrasting

confidence: 46%

Electromyography on Aging

Mitolo¹

1968

Gerontology

View full text Add to dashboard Cite

“…Further evidence for this effect was provided by the analysis of spectral variables of surface EMG (6,35) and of the duration of intramuscular action potentials (5,10,19).…”

Section: Action Potential Propertiesmentioning

confidence: 99%

“…The duration of intramuscular action potentials decreases with increasing temperature (5,10), which indirectly reflects an increase in conduction velocity. Direct measure of conduction velocity in frog muscle fibers (19) and human motor units (42) has confirmed this interpretation.…”

mentioning

confidence: 99%

Effect of temperature on spike-triggered average torque and electrophysiological properties of low-threshold motor units

Farina

Arendt-Nielsen²,

Graven‐Nielsen³

2005

Journal of Applied Physiology

View full text Add to dashboard Cite

Farina, Dario, Lars Arendt-Nielsen, and Thomas GravenNielsen. Effect of temperature on spike-triggered average torque and electrophysiological properties of low-threshold motor units. J Appl Physiol 99: 197-203, 2005. First published March 10, 2005 doi:10.1152/japplphysiol.00059.2005.-The aim of the study was to jointly analyze temperature-induced changes in low-threshold single motor unit twitch torque and action potential properties. Joint torque, multichannel surface, and intramuscular electromyographic signals were recorded from the tibialis anterior muscle of 12 subjects who were instructed to identify the activity of a target motor unit using intramuscular electromyographic signals as feedback. The target motor unit was activated at the minimum stable discharge rate in seven 3-min-long contractions. The first three contractions (C1-C3) were performed at 33°C skin temperature. After 5 min, the subject performed three contractions at 33°C (T1), 39°C (T2), and 45°C (T3), followed by a contraction at 33°C (C4) skin temperature. Twitch torque and multichannel surface action potential of the target motor unit were obtained by spike-triggered averaging. Discharge rate (mean Ϯ SE, 7.1 Ϯ 0.5 pulses/s), interpulse interval variability (35.8 Ϯ 9.2%), and recruitment threshold (4.5 Ϯ 0.4% of the maximal voluntary torque) were not different among the seven contractions. None of the investigated variables were different among C1-C3, T1, and C4. Conduction velocity and peak twitch torque increased with temperature (P Ͻ 0.05; T1: 3.53 Ϯ 0.21 m/s and 0.82 Ϯ 0.23 mN ⅐ m, T2: 3.93 Ϯ 0.24 m/s and 1.17 Ϯ 0.36 mN ⅐ m, T3: 4.35 Ϯ 0.25 m/s and 1.46 Ϯ 0.40 mN ⅐ m, respectively). Twitch time to peak and surface action potential peak-to-peak amplitude were smaller in T3 (61.8 Ϯ 2.0 ms and 27.4 Ϯ 5.1 V, respectively) than in T1 (71.9 Ϯ 4.1 ms and 35.0 Ϯ 6.5 V, respectively) (P Ͻ 0.05). The relative increase in conduction velocity between T1 and T3 was positively correlated (P Ͻ 0.05) with the increase in twitch peak amplitude (r 2 ϭ 0.48), with the decrease in twitch time to peak (r 2 ϭ 0.43), and with the decrease in action potential amplitude (r 2 ϭ 0.50). In conclusion, temperature-induced modifications in fiber membrane conduction properties may have a direct effect on contractile motor unit properties. twitch torque; surface electromyogram; intramuscular electromyogram

show abstract

“…The amplitude of the responses was measured from peak to peak on a photographic superimposition of 5 sweeps in each experi mental step. Using concentric needle electrodes, quantitative EMG examination of the medial gastrocnemius muscle was performed on the paretic side in 4 patients and bilaterally in 1 patient according to the method reported by Buchthal et al [ 18], Moreover, spontaneous activity was searched for on vastus lateralis and tibialis anterior mus cles of both sides in 5 patients. Findings were compared with agematched controls from our laboratory.…”

Section: Methodsmentioning

confidence: 99%

Muscle Rearrangement in Patients with Hemiparesis after Stroke: An Electrophysiological and Morphological Study

et al. 1993

View full text Add to dashboard Cite

Skeletal muscle changes were evaluated in patients suffering from hemiparesis after stroke. Concentric needle EMG and single fiber EMG of the paretic gastrocnemius medialis muscle were performed. Maximal amplitude of H, T and M responses in calf muscles of both the affected and the unaffected sides were determined by usual electrophysiological techniques. Muscle biopsy of the lateral gastrocnemius muscle of the affected side was performed to determine the distribution of fiber types and fiber sizes. Fibrillation activity and positive sharp waves occurred in paretic muscles in patients with more recent hemiparesis while the duration of motor unit potentials was prolonged in patients with long-lasting disease. The H/M ratio was increased on the paretic side. The percentage of type 1 fibers was augmented in most patients with normal mean diameter and low atrophy factor. The percentage of type 2 fibers was reduced with decreased mean diameters and with a high atrophy factor. Such changes may be related to inactivity or transsynaptic degeneration of type 2 motoneurons as a consequence of the interruption of the corticospinal tract. Increased percentage of type 1 fibers may be due to a collateral reinnervation process or a motor unit type transformation.

show abstract

Action Potential Paraneters in Normal Human Musele and their Physiological Determinants

Cited by 218 publications

References 12 publications

Electromyography on Aging

Electromyography on Aging

Effect of temperature on spike-triggered average torque and electrophysiological properties of low-threshold motor units

Muscle Rearrangement in Patients with Hemiparesis after Stroke: An Electrophysiological and Morphological Study

Contact Info

Product

Resources

About