Age-related changes in the frequency profile of children's finger tremor.

Little consensus exists as to the age-related pattern of change in the frequency characteristics of postural tremor through childhood. We investigated postural finger tremor of children (6 and 10 years) and adults (18-22 years) using accelerometers under dual and single limb conditions (10s trials). The postural tremor of the children exhibited proportionally more power below 10 Hz and less power above 20 Hz than that of the adults. It also showed a significantly lower peak frequency and lower proportion of power at the peak frequency than the adults in the 15-30 Hz frequency band but did not differ significantly from the adults in peak frequency or proportion of power at the peak frequency in the 5-15 Hz frequency band. The greater relative contribution of fast time scales over the 1-30 Hz frequency band in the organization of the postural tremor of the adults in comparison to the children may be a contributing factor to adult's typically observed reduced motor skill performance variability.