Surface myoelectric signal cross-talk among muscles of the leg

doi:10.1016/0013-4694(88)90169-1

Electroencephalography and Clinical Neurophysiology

Volume 69, Issue 6, June 1988, Pages 568-575

https://doi.org/10.1016/0013-4694(88)90169-1 Get rights and content

Abstract

Surface myoelectric signals were detected from the skin surface above the tibialis anterior muscle, the peroneus brevis muscle, the soleus muscle and the tibial bone during selective maximal electrical stimulation of the tibialis anterior muscle in 12 normal subjects. The double differential technique developed by Broman et. al. (1985) was used to determine if the detected signal was due to volume conduction from the tibialis anterior fibers. The peak-to-peak (PP), average rectified (ARV) and root mean square (RMS) amplitudes of the M waves were computed for each detection location. The values detected on the tibial bone, on the peroneus and on the soleus muscles were normalized with respect to those detected on the tibialis anterior and ranged from 4.8% to 33.0% (PP), 4.7% to 36.0% (ARV), and 7.7% to 37.4% (RMS) for the tibial bone area; from 4.0% to 20.0% (PP), 3.5% to 10.0% (ARV), and 3.0% to 10.0% (RMS) for the peroneous brevis muscle area; and from 3.0% to 8.0% (PP), 3.4% to 9.1% (ARV), and 2.0% to 9.8% (RMS) for the soleus muscle area. Neither peak-to-peak values, average rectified values nor root mean square values appeared to be correlated with leg size.

It is concluded that surface myoelectric signal detected on the skin above a leg muscle and having a peak-to-peak amplitude of up to 16.6% of a signal detected above a neighboring muscle may be due to cross-talk rather than to activation of the muscle below the electrode.

References (9)

H. Broman et al.
A note on the noninvasive estimation of muscle fiber conduction velocity
IEEE Trans. Biomed. Eng.
(1985)
C.J. De Luca et al.
Voluntary control of motor units in human antagonist muscles: coactivation and reciprocal activation
J. Neurophysiol.
(1987)
B. Etnyre et al.
Comparison of wire and surface electrode recordings between antagonist pairs of muscles
R. Merletti et al.
Suppression of stimulation artifacts from myoelectric evoked potential recordings

There are more references available in the full text version of this article.

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This work was performed at the NeuroMuscular Research Center of Boston University, Boston, MA, U.S.A.

Major support was provided by the Liberty Mutual Insurance Company. Partial support was provided by the National Research Council of Italy under Contracts 83.02457.07 and 85.02213.07 granted to the Department of Electronics of the Politecnico di Torino. During this investigation Dr. R. Merletti was on leave from the Department of Electronics of the Politecnico di Torino, Italy.

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Surface myoelectric signal cross-talk among muscles of the leg☆

Abstract

A note on the noninvasive estimation of muscle fiber conduction velocity

IEEE Trans. Biomed. Eng.

Voluntary control of motor units in human antagonist muscles: coactivation and reciprocal activation

J. Neurophysiol.

Comparison of wire and surface electrode recordings between antagonist pairs of muscles

Suppression of stimulation artifacts from myoelectric evoked potential recordings