  The influence of fatiguing stimuli applied to the quadriceps femoris on the
tremor of the index finger on sixteen healthy subjects has been investigated,
by measuring the acceleration and the electromyography activity of the extensor
digitorum at two different speeds. No significant changes in the basal
condition could be measured at 0.52 rad/s. However, at 1.05 rad/s the tremor
amplitude (12.23%, p<0.05) and the electromyography activity (20.19%, p<0.05)
increased in the time domain. In the frequential domain, the peak associated to
the acceleration increased in 26.30% (p<0.05), while the electromiography
activity experienced an increase of 81.34% (p<0.05). The largest change in
frequency took place in the range 7-17 Hz. The discussion of the results leads
to the conclusion that the supraespinal mechanism is responsible for the
measured effect.
