Ann Clin Neurophysiol.  2018 Jan;20(1):26-30. 10.14253/acn.2018.20.1.26.

Applicability of the digital instrument to improve the reproducibility of motor unit number index

Affiliations
  • 1Department of Neurology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Korea. icandr@hanmail.net

Abstract

BACKGROUND
The motor unit number index (MUNIX) and motor unit size index (MUSIX) refer to the electrophysiological measurement of the motor units using the surface electromyographic interference pattern (SIP) recorded during graded muscle contraction. In order to improve the reliability and reproducibility of MUNIX by the systematization of the graded muscle contractions, we applied a digital hand instrument to the procedure of recording SIP signals.
METHODS
We tested the applicability of the digital instrument in the MUNIX technique by assessing the mean values and the reproducibility of the MUNIX involving the abductor pollicis brevis (APB) and the abductor digiti minimi (ADM) muscles in 30 healthy adults.
RESULTS
The digital dynamometer was successfully applied to the MUNIX measurements of the APB and ADM muscles, and showed high reproducibility across trials.
CONCLUSIONS
Application of the digital instrument would be useful in improving the reliability and reproducibility of MUNIX.

Keyword

Motor neurons; Motor neuron disease; Amyotrophic lateral sclerosis; Electromyography

MeSH Terms

Adult
Amyotrophic Lateral Sclerosis
Dental Instruments
Electromyography
Humans
Motor Neuron Disease
Motor Neurons
Muscle Contraction
Muscles

Figure

  • Fig. 1 Scatter plots of the results between operators (#1 and #2) of the motor unit number index (MUNIX) and motor unit size index (MUSIX) measurements with using the digital instrument in the abductor pollicis brevis (APB, A and C) and abductor digiti minimi (ADM, B and D) muscles of 30 healthy subjects.


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