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Simultaneous Intracellular Recording of a Lumbar Motoneuron and the Force Produced by its Motor Unit in the Adult Mouse In vivo
Published on: December 5, 2012
Innervation zones in the back muscles investigated by multichannel surface EMG
M Shiraishi1, T Masuda, T Sadoyama
1Institute of Health and Sport Sciences, University of Tsukuba, Tennodai 1-1, Tsukuba, Ibaraki, Japan.
Summary
Surface electrode arrays can locate muscle innervation zones and estimate conduction velocity. This study found the technique effective for the trapezius and latissimus dorsi but not the erector spinae.
Area of Science:
- Biomedical Engineering
- Neuroscience
- Biomechanics
Background:
- Surface electrode arrays detect motor unit action potentials (MUAPs) to identify innervation zones and estimate muscle fiber conduction velocity.
- This technique is well-established for limb muscles but its applicability to back muscles is less understood.
Purpose of the Study:
- To assess the feasibility of using surface electrode arrays to map innervation zones in three human back muscles: trapezius, latissimus dorsi, and erector spinae.
- To evaluate the utility of this method for applications in ergonomics and low back pain research.
Main Methods:
- Employing a linear surface electrode array to detect MUAP propagation.
- Analyzing the spatial distribution of MUAP sources to define innervation zones.
- Comparing results across trapezius, latissimus dorsi, and erector spinae muscles.
Main Results:
- Clear MUAP propagation and narrowly banded innervation zones were observed in the trapezius.
- MUAP propagation was less distinct in the latissimus dorsi, but innervation zones were identifiable and concentrically distributed.
- No clear MUAP propagation was detected in the erector spinae, preventing innervation zone definition with this technique.
Conclusions:
- Surface electrode array technique is applicable for characterizing innervation zones in the trapezius and latissimus dorsi.
- The technique is not suitable for the erector spinae due to unclear MUAP propagation.
- Findings have implications for understanding back muscle function in ergonomic and pain studies.
