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Quantitative EMG and motor unit recruitment threshold using a concentric needle with quadrifilar electrode
Author(s) -
Akaboshi Kazuto,
Masakado Yoshihisa,
Chino Naoichi
Publication year - 2000
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/(sici)1097-4598(200003)23:3<361::aid-mus7>3.0.co;2-o
Subject(s) - concentric , motor unit , biceps , electromyography , motor unit recruitment , biomedical engineering , biceps brachii muscle , physical medicine and rehabilitation , anatomy , dorsum , index finger , medicine , muscle contraction , mathematics , geometry
According to Henneman's size principle, small motor units are recruited before large ones. We used the electromyographic (EMG) signal decomposition technique to determine the quantitative relationships between five motor unit action potential (MUAP) parameters (amplitude, duration, area, thickness, and size index) and the recruitment threshold of the motor units recruited up to 50% of the maximum voluntary contraction in the first dorsal interosseous, biceps brachii, rectus femoris, and tibialis anterior muscles of 5 healthy young men. In each muscle, the amplitude, duration, area, and size index had significant, positive high correlations with the motor unit recruitment thresholds. We conclude that the size principle applies to recordings made with concentric needle EMG electrodes under special recording conditions, and therefore that more importance should be attached to the patient's contraction force during EMG examinations in order to evaluate MUAPs for electrodiagnostic purposes. © 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 361–367, 2000