title: Effects of practice on magnitude and structure of force variability during periodic unimanual isometric force production.
abstract: The present study examined practice effects on the magnitude and structure of force variability using multiscale entropy analysis. Ten male participants (M age = 22.5 yr., SD = 1.7) produced unimanual isometric forces cycling between low levels of maximum voluntary contraction. The participants practiced the motor task over ten blocks: one block consisted of one self-paced recall trial immediately after nine audibly-synchronized practice trials with feedback of force output. Although the coefficient of variation of the force-time series in the recall trial had a greater magnitude than that in the practice, the recall trial had lower sample entropy values of force output (higher time structure of force variability). Multiscale entropy analysis did not find a practice effect on the time structure of force variability on a short time scale (10 msec.) but did on a long time scale (20-60 msec.). Different tasks have different time scales of force output, and the task demands of the present experiment emphasized the long time scales.
authors: The Joint Graduate School in Science of School Education, Hyogo University of Teacher Education, Naruto-shi, Japan.
authors: Junya
authors: J
authors: Masumoto
authors: Nobuyuki
authors: N
authors: Inui
mesh_terms: D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D011214:Practice, Psychological; D011597:Psychomotor Performance; D055815:Young Adult