Study type: Medical/biological study (experimental study)

Transient effect of low-intensity magnetic field on human motor control. med./bio.

Published in: Med Eng Phys 2006; 28 (8): 827-836

Aim of study (acc. to author)

This study was conducted to determine if the transition of 50 Hz, 1 mT magnetic field ("on" to "off" or vice versa) could have a transient effect on postural tremor.

Background/further details

Twenty-four healthy men in the age of 20 to 50 years participated in a single session of 65 minutes including both magnetic field exposure and sham exposure. Participants had to maintain their index finger in a fixed position. Postural tremor was recorded in the range of 10 seconds before (recording begin) and after (recording end) magnetic field transition.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 50 Hz
Exposure duration: 14 min real or sham exposure , 3 min rest, 14 min real or sham exposure , 3 min rest,... for 65 min; real exposure consisting of 2 power off-on and 2 power on-off transitions of 62 s each

General information

for further information on the setup see: Nguyen DH., Richard D., Plante M., "Système de génération du champ magnétiques et de commande des essais pour l'étude de l'effet des champs magnétiques sur le système nerveux central et périphérique par l'exploration des tremblements." Hydro-Québec Montréal 2004

Exposure 1

Main characteristics
Frequency 50 Hz
Type
Waveform
Exposure duration 14 min real or sham exposure , 3 min rest, 14 min real or sham exposure , 3 min rest,... for 65 min; real exposure consisting of 2 power off-on and 2 power on-off transitions of 62 s each
Exposure setup
Exposure source
  • not specified
Setup magnetic field centered at the level of the testperson's head
Sham exposure A sham exposure was conducted.
Parameters
Measurand Value Type Method Mass Remarks
magnetic flux density 1 mT - - - -

Reference articles

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • during exposure

Main outcome of study (acc. to author)

The magnetic field exposure did not cause magnetic field transition effects ("on"/"off"). Heart rate and skin temperature were not affected either.
The "mean sginificant power" of the postural tremor was significantly higher at the beginning of the recording than at the end of the recording, independently of the magnetic field transition and more pronounced in the magnetic field exposure than sham exposure.
These data indicate a relaxing effect of extremely low frequency electromagnetic field on motor control resulting in an attenuation of postural tremor intensity.

Study character:

Study funded by

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