Alessio Gallina1,2, Taian Vieira1,3. 1. Laboratorio per l'Ingegneria del Sistema Nuromuscolare, Dipartimento di Ingegneria Elettronica, Politecnico di Torino, Via Cavalli 22/h, 10138, Torino, Italy. 2. Graduate Program in Rehabilitation Sciences, Department of Physical Therapy, University of British Columbia, Vancouver (BC), Canada. 3. Escola de Educação Física e Desportos, Departamento de Arte Corporal, Universidade Federal do Rio de Janeiro, Rio di Janeiro, Brazil.
Abstract
INTRODUCTION: The aim of this study was to determine whether muscle fibers innervated by single motor neurons are confined in small subvolumes of the vastus medialis (VM) and if motor unit fiber orientation depends on their position within the muscle. METHODS: Single motor units were identified from a grid of surface electrodes. The size of their surface representation and fiber orientation were extracted using an algorithm validated on simulated signals. RESULTS: The action potentials of 77 motor units were represented locally on the skin (10th-90th percentiles: 14-25 mm). According to simulations, this indicates territories smaller than 11.8-64.8 mm. Motor units in distal regions of VM had fibers at a greater angle than those in proximal regions (R = -0.54, P < 0.001). CONCLUSION: Motor units with small territories and varying fiber orientations may be an anatomical predisposition to regulate how regions within VM apply forces to the patella. This could help to redistribute loads within the joint in painful conditions.
INTRODUCTION: The aim of this study was to determine whether muscle fibers innervated by single motor neurons are confined in small subvolumes of the vastus medialis (VM) and if motor unit fiber orientation depends on their position within the muscle. METHODS: Single motor units were identified from a grid of surface electrodes. The size of their surface representation and fiber orientation were extracted using an algorithm validated on simulated signals. RESULTS: The action potentials of 77 motor units were represented locally on the skin (10th-90th percentiles: 14-25 mm). According to simulations, this indicates territories smaller than 11.8-64.8 mm. Motor units in distal regions of VM had fibers at a greater angle than those in proximal regions (R = -0.54, P < 0.001). CONCLUSION: Motor units with small territories and varying fiber orientations may be an anatomical predisposition to regulate how regions within VM apply forces to the patella. This could help to redistribute loads within the joint in painful conditions.
Authors: Daniele Borzelli; Marco Gazzoni; Alberto Botter; Laura Gastaldi; Andrea d'Avella; Taian M Vieira Journal: Eur J Appl Physiol Date: 2020-02-19 Impact factor: 3.078
Authors: Marco Carbonaro; Kristen M Meiburger; Silvia Seoni; Emma F Hodson-Tole; Taian Vieira; Alberto Botter Journal: Sci Rep Date: 2022-05-25 Impact factor: 4.996