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May 1962

Motor Unit Potentials at Different Ages

Author Affiliations

From the Institute of Neurophysiology, University of Copenhagen.

Arch Neurol. 1962;6(5):366-373. doi:10.1001/archneur.1962.00450230028004

Changes in the mean duration of motor unit potentials, as well as in their voltage and shape, are electromyographic criteria which may contribute to a differentiation between a myopathy and a neuropathy.1 Normal data for these parameters have been obtained in different muscles in adults,2-4 but only in a few muscles in infants.5-8 Data of the changes in the parameters of the motor unit potentials from infancy to senium are available only for the brachial biceps.5,9 In the study presented in this report, the change in the parameters of the motor unit potentials with age was investigated systematically in the abductor digiti quinti and the brachial biceps.

Material and Method  Subjects.—Mean duration and voltage and the incidence of different shapes were determined in motor unit potentials recorded in the m. abductor digiti quinti and m. brachial biceps of 38 subjects without signs or symptoms of