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Lookup NU author(s): Dr Callum BrownsteinORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
The response of spinal motoneurons to synaptic input greatly depends on the activation of persistent inward currents (PICs), the contribution of which can be estimated through the paired motor unit technique. Yet, the intra-session test–retest reliability of this measurement remains to be fully established. Twenty males performed isometric triangular dorsiflexion contractions to 20 and 50 % of maximal torque at baseline and after a 15-min resting period. High-density electromyographic signals (HD-EMG) of the tibialis anterior were recorded with a 64-electrode matrix. HD-EMG signals were decomposed, and motor units tracked across time points to estimate the contribution of PICs to motoneuron firing through quantification of motor unit recruitment-derecruitment hysteresis (ΔF). A good intraclass correlation coefficient (ICC = 0.75 [0.63, 0.83]) and a large repeated measures correlation coefficient (rrm = 0.65 [0.49, 0.77]; p < 0.001) were found between ΔF values obtained at both time points for 20 % MVC ramps. For 50 % MVC ramps, a good ICC (0.77 [0.65, 0.85]) and a very large repeated measures correlation coefficient (rrm = 0.73 [0.63, 0.80]; p < 0.001) were observed. Our data suggest that ΔF scores can be reliably investigated in tibialis anterior motor units during both low- and moderate-intensity contractions within a single experimental session.
Author(s): Lapole T, Mesquita RN, Baudry S, Souron R, OBrien EK, Brownstein CG, Rozand V
Publication type: Article
Publication status: Published
Journal: Journal of Electromyography and Kinesiology
Year: 2024
Volume: 78
Print publication date: 01/10/2024
Online publication date: 09/06/2024
Acceptance date: 06/06/2024
Date deposited: 29/01/2026
ISSN (print): 1050-6411
ISSN (electronic): 1873-5711
Publisher: Elsevier
URL: https://doi.org/10.1016/j.jelekin.2024.102911
DOI: 10.1016/j.jelekin.2024.102911
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