Faculty Collaboration Database

Recording characteristics of the surface EMG electrodes. Muscle Nerve 1994 Nov;17(11):1317-23

Date

11/01/1994

Pubmed ID

7935554

DOI

10.1002/mus.880171111

Scopus ID

2-s2.0-0028091777 (requires institutional sign-in at Scopus site)   59 Citations

Abstract

Routine motor nerve conduction studies are conducted using surface EMG electrodes. Most techniques of estimating the number of motor units (MUs) are based on surface EMG recordings. Therefore, it is important to assess the uptake area of these electrodes. We recorded surface EMG motor unit action potentials (SMUAPs) from the biceps muscle of normal subjects. The SMUAP amplitude fell from 42 microV for the superficially located MUs (i.e., within 10 mm of skin surface) to 11 microV for the deep MUs (i.e., more than 20 mm from the skin surface). We infer that the pickup radius of the surface electrode is less than 20 mm. The implications of the limited uptake area of the surface electrodes to the analysis of compound muscle action potentials, estimation of the number of MUs, and the surface EMG recordings are discussed.

Author List

Barkhaus PE, Nandedkar SD

Author

Paul E. Barkhaus MD Professor in the Neurology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Action Potentials
Adult
Electrodes
Electromyography
Female
Humans
Male
Middle Aged
Motor Neurons
Muscles