Sex-related differences in corticospinal excitability outcome measures of the biceps brachii during a submaximal elbow flexor contraction.

Autor: Olarogba OB; Human Neurophysiology Lab, School of Human Kinetics and Recreation, St. John's, Newfoundland, Canada., Lockyer EJ; Human Neurophysiology Lab, School of Human Kinetics and Recreation, St. John's, Newfoundland, Canada.; Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada., Antolinez AK; Human Neurophysiology Lab, School of Human Kinetics and Recreation, St. John's, Newfoundland, Canada., Button DC; Human Neurophysiology Lab, School of Human Kinetics and Recreation, St. John's, Newfoundland, Canada.; Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
Jazyk: angličtina
Zdroj: Physiological reports [Physiol Rep] 2024 Aug; Vol. 12 (15), pp. e16102.
DOI: 10.14814/phy2.16102
Abstrakt: The purpose of this study was to investigate the effects of sex, muscle thickness, and subcutaneous fat thickness (SFT) on corticospinal excitability outcome measures of the biceps brachii. Eighteen participants (10 males and 8 females) completed this study. Ultrasound was used to assess biceps brachii muscle thickness and the overlying SFT. Transcranial magnetic stimulation (TMS) was used to determine corticospinal excitability by inducing motor-evoked potentials (MEPs) at eight different TMS intensities from 90% to 160% of active motor threshold (AMT) from the biceps brachii during an isometric contraction of the elbow flexors at 10% of maximum voluntary contraction (MVC). Biceps brachii maximal compound muscle action potential (M max ) was also recorded prior to and after TMS. Males had higher (p < 0.001) biceps brachii muscle thickness and lower SFT, produced higher levels of MVC force and had, on average, higher (p < 0.001) MEP amplitudes at lower (p < 0.05) percentages of maximal stimulator output than females during the 10% elbow flexion MVC. Multiple linear regression modeling revealed that sex was not associated with any of the neurophysiological parameters examined, while SFT showed a positive association with the stimulation intensity required at AMT (p = 0.035) and a negative association with biceps brachii pre-stimulus electromyography (EMG) activity (p = 0.021). Additionally, there was a small positive association between muscle thickness and biceps brachii pre-stimulus EMG activity (p = 0.049). Overall, this study suggests that some measures of corticospinal excitability may be different between the sexes and influenced by SFT and muscle thickness.
(© 2024 The Author(s). Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)
Databáze: MEDLINE
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