Data on fibre size in thirty-six human muscles

Polgár, J. P.; Johnson, Mark; Weightman, D.; Appleton, David R.

doi:10.1016/0022-510x(73)90094-4

Cited by 281 publications

(150 citation statements)

References 7 publications

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“…The mean fibre diameters of individual fibre types, with the exception of subject 5 (type 1 fibres), however, lay within the normal ranges described by Polgar et ai, 23 indicating that in abnormal human muscle an inspec tion of mean fibre diameters alone does not provide an assessment of the extent of atrophy. Preferential fibre type atrophy may be determined from the atrophy factors of individual fibre types.…”

Section: Discussionsupporting

confidence: 50%

Influence of electrical stimulation of the tibialis anterior muscle in paraplegic subjects. 2. Morphological and histochemical properties

Barron²,

et al. 1995

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In adult paraplegic subjects one tibialis anterior muscle received daily electrical stimulation for 4 weeks at twice the motor threshold to determine changes of morphological and histochemical profiles (this paper) and of contractile properties (preceding paperV Bilateral biopsies, obtained 4 weeks before, and immediately after, electrical stimulation, were studied for fibre type proportions, fibre diameters, oxidative capacity, microvascu lature and histopathology, Before stimulation the biopsies showed disuse with increased type 2 fibre proportions and decreased oxidative capacity (succinate dehydrogenase (SOH) activity). The effects of two stimulus patternsl were compared. Following stimulation SOH activity increased significantly in all stimulated muscles. Inconsistent changes occurred in fibre type proportions, fibre diameters, capillary density and capillary/fibre ratios, Both stimulus patterns evoked similar results. In five/seven subjects sub sarcolemmal vacuolation was observed, Electrical stimulation for 4 weeks at only twice motor threshold improves oxidative capacity, but different stimulus parameters are probably needed for significant fibre type conversion.

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Section: Discussionsupporting

confidence: 50%

Influence of electrical stimulation of the tibialis anterior muscle in paraplegic subjects. 2. Morphological and histochemical properties

Barron²,

et al. 1995

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“…The differences in fibre diameters and types are also related to the gender difference 53 . Type II fibres have a larger diameter than type I fibres and are recruited later in a contraction, thus the action potential conduction velocity increases with increasing levels of contraction force 54 . This can also produce an increase in the MNF and MDF values.…”

Section: Identification and Possible Causes For The Conflicting Resultsmentioning

confidence: 99%

The effects of the force of contraction and elbow joint angle on mean and median frequency analysis for muscle fatigue evaluation

Thongpanja¹,

Phinyomark²,

Hu³

et al. 2015

ScienceAsia

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Mean frequency (MNF) and median frequency (MDF) are often used to assess muscular fatigue from surface electromyography (sEMG) signals. To determine muscle fatigue at different levels of isometric and dynamic contractions, it is necessary to know the relationship between the force of contraction and the MNF/MDF methods. Despite numerous studies, no unique answer has been found. This study re-examines this relationship by investigating 19 subjects and performing isometric and dynamic contractions over a full elbow range of motion measured from the biceps brachii muscle. We obtained the following key results: (i) a strong positive relationship between MNF/MDF methods and the force of contraction was found frequently during isometric contractions at an angle less than 90°and during dynamic contractions in 3 subjects (16%); (ii) a strong negative relationship during isometric contractions at an angle greater than 90°and during dynamic contractions in 8 subjects (42%), and (iii) no strong linear relationship during isometric contractions for all the angles and during dynamic contractions in 8 subjects (42%). After possible causes for these conflicting results are discussed, the study then investigates if it is possible to use anthropometric variables of subjects as the criteria to create homogeneous subgroups of relationships. A number of anthropometric variables were used to separate the subgroups, i.e., the forearm and biceps circumferences for males and the hand and shoulder breadths for females.

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“…Changes in MUP amplitude and area in this situation critically depend on the density of muscle fibers per volume unit, and on muscle fiber dimensions (Stålberg & Karlsson, 2001). The diameters of both, type I und type II fibers have previously been determined in human muscles from autopsy specimens (Polgar, Johnson, Weightman, & Appleton, 1973). In the LV muscle, the diameters tended to be larger than in the ES and in the BB muscles, respectively (Polgar et al., 1973).…”

Section: Discussionmentioning

confidence: 99%

“…The diameters of both, type I und type II fibers have previously been determined in human muscles from autopsy specimens (Polgar, Johnson, Weightman, & Appleton, 1973). In the LV muscle, the diameters tended to be larger than in the ES and in the BB muscles, respectively (Polgar et al., 1973). The larger MUP amplitude and area values determined for the LV as compared to BB and ES muscles in the present investigation may be due to such differences in muscle fiber dimensions.…”

Section: Discussionmentioning

confidence: 99%

Motor unit potentials of the erector spinae muscle by concentric needle electromyography

et al. 2017

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IntroductionThe needle electromyography (EMG) serves to supply additional information in patients with suspected neuromuscular disorders. We aimed to provide motor unit potential (MUP) data by concentric needle EMG in the erector spinae (ES) in comparison with biceps brachii (BB) and lateral vastus (LV).MethodsElectromyography MUP data (n) were obtained in ES (517), BB (539), and LV (627) in 32 healthy volunteers (16f).ResultsMotor unit potential data: amplitude (μV) 393 ± 174 (ES), 375 ± 162 (BB), and 577 ± 304 (LV); duration (ms) 10.4 ± 2.4 (ES), 10.1 ± 2.1 (BB), and 11.1 ± 2.3 (LV), area (μV × ms) 585 ± 327 (ES), 538 ± 267 (BB), and 881 ± 492 (LV); phase number 3.23 ± 0.94 (ES), 2.98 ± 0.76 (BB), and 3.19 ± 0.81 (LV); size index 0.60 ± 0.56 (ES), 0.51 ± 0.53 (BB), and 0.96 ± 0.55 (LV). LV displayed higher values (p at least <.001) for MUP amplitude, duration, area, and size index as compared to both, BB and ES.ConclusionConcentric needle EMG investigations in healthy adult human subjects revealed similar MUP parameters in the ES and BB muscles, while in the LV muscle MUP amplitude, duration, area, and size index were significantly larger. Different neuromuscular disorders display a predominant involvement of proximally located muscles such as truncal muscles. The present results given here may facilitate the diagnosis of neuromuscular disorders.

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Data on fibre size in thirty-six human muscles

Cited by 281 publications

References 7 publications

Influence of electrical stimulation of the tibialis anterior muscle in paraplegic subjects. 2. Morphological and histochemical properties

Influence of electrical stimulation of the tibialis anterior muscle in paraplegic subjects. 2. Morphological and histochemical properties

The effects of the force of contraction and elbow joint angle on mean and median frequency analysis for muscle fatigue evaluation

Motor unit potentials of the erector spinae muscle by concentric needle electromyography

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