Peripheral and extra torques generated by stimulation pattern 2. At the top, the first two graphs show the amplitude histogram and the absolute value of the FFT of the Gaussian white noise acceleration signal and the third graph shows the absolute value of the FFT of the sinusoidal acceleration signal measured at the tip of the shaker. A) Schematic representation of stimulation pattern 2, showing the time course of 8 intermittent bursts of vibratory stimuli of 2 s duration (rectangular boxes) together with a constant background 20 Hz electrical stimulation. B) Average plantarflexion torque as a function of time (n = 8, thick line) with SD shown in light shade. Bars (thin line) represent the values of peripheral torque (PT) and extra torques (ETs, means ± SDs). The eight extra torque values generated by the series of 100-Hz bursts are labeled ET1 -- ET8. Data are from a representative subject. C) The same as in B but for the white noise vibratory bursts instead of the 100-Hz sine wave bursts (both B and C are data from the same representative subject). D and E) Average extra torques (± SEMs) representing group data (n = 48) for the stimuli utilizing 100 Hz sine waves (D) and white noise (E). Asterisks indicate extra torque values significantly different from zero (p < 0,05).