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Concentric macro electromyography
Author(s) -
Jabre Joe F.
Publication year - 1991
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880140904
Subject(s) - concentric , motor unit , macro , electromyography , biomedical engineering , waveform , muscle fibre , computer science , mathematics , anatomy , physical medicine and rehabilitation , medicine , voltage , engineering , electrical engineering , geometry , skeletal muscle , programming language
Concentric EMG electrodes can record from a few (10 to 15) muscle fibers of a motor unit (MU). Macro EMG, is able to record from the majority of muscle fibers in the MU. The macro EMG electrode uses a single fiber action potential (SFAP) on one channel to trigger the time locked cannula (macro) response on the other channel. To study the concentric motor unit action potential (MUAP), alongside the macro potential, we built a needle electrode combining concentric and macro recording surfaces. The study of 240 motor units in 10 healthy subjects with the single fiber (SF macro) and concentric macro (conmac) electrodes revealed no significant differences between macro potentials areas and amplitudes obtained with either electrode. The ability to study a small and a large section of the motor unit simultaneously offers insights into the local or global nature of motor unit changes not otherwise available to the electromyographer. It also reveals which concentric parameters correlate best with the macro potential and, can even be of great help with the newer EMG signal decomposition techniques; by identifying each motor unit by its concentric and macro waveform simultaneously, it will allow for the “making” of these motor units helping to reduce the risk of their misclassification when the concentric MUAP is used alone.