Voluntary Dissociation of Motor Unit Activity in the Vastii Muscles.

Λεπτομέρειες βιβλιογραφικής εγγραφής
Τίτλος:	Voluntary Dissociation of Motor Unit Activity in the Vastii Muscles.
Συγγραφείς:	Haller D; Neuromuscular Physiology and Neural Interfacing Laboratory, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91052, Germany., Beermann F; Neuromuscular Physiology and Neural Interfacing Laboratory, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91052, Germany., Sîmpetru RC; Neuromuscular Physiology and Neural Interfacing Laboratory, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91052, Germany., Hofbeck L; Traumatology and Orthopaedics, Universitätsklinikum Erlangen, Erlangen 91054, Germany., Enoka RM; Department of Integrative Physiology, University of Colorado Boulder, Boulder, Colorado 80309-0354., Del Vecchio A; Neuromuscular Physiology and Neural Interfacing Laboratory, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91052, Germany alessandro.del.vecchio@fau.de.
Πηγή:	The Journal of neuroscience : the official journal of the Society for Neuroscience [J Neurosci] 2026 May 27; Vol. 46 (21). Date of Electronic Publication: 2026 May 27.
Τύπος έκδοσης:	Journal Article
Γλώσσα:	English
Στοιχεία περιοδικού:	Publisher: Society for Neuroscience Country of Publication: United States NLM ID: 8102140 Publication Model: Electronic Cited Medium: Internet ISSN: 1529-2401 (Electronic) Linking ISSN: 02706474 NLM ISO Abbreviation: J Neurosci Subsets: MEDLINE
Imprint Name(s):	Publication: Washington, DC : Society for Neuroscience Original Publication: [Baltimore, Md.] : The Society, c1981-
Ιατρικοί όροι (MeSH):	Isometric Contraction/physiology , Recruitment, Neurophysiological/physiology , Quadriceps Muscle/physiology , Motor Neurons/physiology, Humans ; Male ; Female ; Electromyography ; Adult ; Young Adult
Περίληψη:	The central nervous system controls movement with consistent activation patterns across muscles and motor units (MUs), suggesting the presence of a relatively fixed and high-dimensional number of neural constraints on voluntary actions. In the human quadriceps, the vastus medialis (VM) and vastus lateralis (VL) contribute to the knee extensor torque and are considered a synergistic pair largely activated by shared neural inputs. However, some evidence suggests that these muscles or even subregions within them can be controlled independently. We investigated whether humans can dissociate neural input to VM and VL during isometric contractions. Ten participants (six males, four females) received real-time feedback from multiple intramuscular electromyography (EMG) electrodes inserted into different regions of the VM and VL while attempting to activate each muscle or region selectively. Nine out of ten participants were able to separate VM and VL activity based on the intramuscular EMG feedback. However, MU decomposition from the intramuscular EMGs revealed that selective recruitment of a unique set of MUs was possible only within the proximal region of VM. In contrast, we found highly correlated activity between MUs in VL and distal VM. Correlation analyses confirmed that the proximal VM exhibited distinct activation profiles compared with both distal VM and VL, supporting the existence of compartmentalized control within VM. These findings demonstrate that it is possible to dissociate the activation of MUs within this synergistic muscle group during low-force isometric contractions. (Copyright © 2026 Haller et al.)
Competing Interests:	The authors declare no competing financial interests.
Contributed Indexing:	Keywords: intramuscular EMG; motor unit recruitment; muscle synergies; vastus lateralis; vastus medialis; volitional motor control
Entry Date(s):	Date Created: 20260424 Date Completed: 20260715 Latest Revision: 20260715
Update Code:	20260716
PubMed Central ID:	PMC13217533
DOI:	10.1523/JNEUROSCI.1982-25.2026
PMID:	42031565
Βάση Δεδομένων:	MEDLINE

Περιγραφή
ISSN:	1529-2401
DOI:	10.1523/JNEUROSCI.1982-25.2026