Fig. 3

Example of the smoothing spline signal for all exercise as: a thumb fore-finger tapping, b hand opening closing, c pronation supination, d postural tremor. The frequency of each movement is obtained as the inverse of the time between consecutive peaks. The frequency of each movement was defined as the inverse of the time difference between the second and first peaks. The amplitude of each movement is obtained as the difference in amplitude from a peak to the next valley. Opening speed of hand and finger tapping were obtained with the distance travel between peak from the previous valley divided by time of hand or finger move from valley to peak. Similarly, for closing speed of hand or finger tapping were obtained with the distance travel between current peak to the next valley divided by time travel from current peak to the next valley. For pronation, angular velocity was obtained change in the angle from peak to last valley divided by time. Similarly, for supination, angular velocity was obtained with change in the angle from consecutive peak and valley divided by time duration of the change in angle from consecutive peak to valley. In postural tremor average velocity of fingers was used to obtain the signal strength and power in the band of interest 8–12 Hz. A Fast Fourier Transformation was used to obtain the power spectrum. Average of power spectrum was considered as the signal strength. Power b/w 8–12 HZ obtained with the average of power spectrum between 8 and 12 HZ. The tremor frequency is defined as the frequency with the maximum power in the spectrum