ON THE VOLUNTARY CONTROL OF MUSCLE FORCE / 体力科学

ABSTRACT

The pressure exerted by the index finger tip was continuously recorded while the human subject was trying to maintain the pressure at the level of a given pressure (this pressure is named ‘target pressure’, 0.5-500g) with optical information for ten minutes, and the results obtained under various conditions were analysed.<BR>1) The errors tended to be minimal in the range between 40 and 50g target pressure, and increased approximately in proportion to the target pressure above 50g.<BR>2) When the subject relaxed his index finger, the errors decreased with decreasing target pressure in the range of less than 50g.<BR>3) The errors were increased by excluding optical information. In target pressure less than 50g, the increment of the errors due to a decrease in the skin pressure intensity was further increased by exclusion of optical information.<BR>4) In small target pressures, the errors tended to decrease transiently in evening, while in large target pressures the errors showed a gradual increase from morning toward evening.<BR>5) The errors showed generally minimal values 2 or 3 minutes after the beginning of the measurement, and thereafter increased more remarkably in large target pressures than small ones.