Title
Quantifying Spatial Activation Patterns of Motor Units in Finger Extensor Muscles
Abstract
The ability to expertly control different fingers contributes to hand dexterity during object manipulation in daily life activities. The macroscopic spatial patterns of muscle activations during finger movements using global surface electromyography (sEMG) have been widely researched. However, the spatial activation patterns of microscopic motor units (MUs) under different finger movements have not been well investigated. The present work aims to quantify MU spatial activation patterns during movement of distinct fingers (index, middle, ring and little finger). Specifically, we focused on extensor muscles during extension contractions. Motor unit action potentials (MUAPs) during movement of each finger were obtained through decomposition of high-density sEMG (HD-sEMG). First, we quantified the spatial activation patterns of MUs for each finger based on 2-dimension (2-D) root-mean-square (RMS) maps of MUAP grids after spike-triggered averaging. We found that these activation patterns under different finger movements are distinct along the distal-proximal direction, but with partial overlap. Second, to further evaluate MU separability, we classified the spatial activation pattern of each individual MU under distinct finger movement and associated each MU with its corresponding finger with Regularized Uncorrelated Multilinear Discriminant Analysis (RUMLDA). A high accuracy of MU-finger classification tested on 12 subjects with a mean of 88.98% was achieved. The quantification of MU spatial activation patterns could be beneficial to studies of neural mechanisms of the hand. To the best of our knowledge, this is the first work which manages to quantify MU behaviors under different finger movements.
Year
DOI
Venue
2021
10.1109/JBHI.2020.3002329
IEEE Journal of Biomedical and Health Informatics
Keywords
DocType
Volume
Electrodes,Electromyography,Fingers,Humans,Movement,Muscle, Skeletal
Journal
25
Issue
ISSN
Citations 
3
2168-2194
0
PageRank 
References 
Authors
0.34
0
8
Name
Order
Citations
PageRank
Xinyu Jiang131.72
Haoran Ren201.35
Ke Xu31392171.73
Xinming Ye410.68
Chenyun Dai587.61
Edward A. Clancy6176.49
Yuan-Ting Zhang730119.79
Wei Chen89639.08