<bold>Purpose.</bold> The aim of the present work was to identify factors and neurophysiological mechanisms that may determine a robust and very stable postural control in athletes. <bold>Basic procedures.</bold> Postural performance in quiet stance was compared in 23 volleyball players from the Polish second league with 24 age-matched healthy physically active male subjects (controls). All participants stood quietly for 20 s on a force plate with their eyes open, while the center of pressure (COP) was recorded with the sampling rate of 20 Hz in both: the anterior-posterior (AP) and medial-lateral (ML) planes. From the recorded signals the COP dispersion measures, postural frequency and stiffness were computed. <bold>Main findings.</bold> The players displayed lower COP variability in the ML plane (p < 0.05) and lower COP range than controls in both planes (p < 0.01). Their COP mean velocity was higher in the AP plane (p < 0.0001) and the ML plane (p < 0.01) than in controls. Together, these findings indicated the presence of an additional low-amplitude and high-frequency signal superimposed on the COP in athletes but not in controls. Superior body stability and different mode of automatic postural control observed in the players challenge recent views on the relationships between attention resources allocation and its consequences to the selection and implementation of postural strategies. <bold>Conclusions.</bold> The volleyball players have superior body stability and different mode of automatic postural control as compared with the control group. Postural strategies of athletes may result from slight muscular adjustments that adopt mechanisms similar to stochastic resonance to monitor an instantaneous body vertical with greater efficiently.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
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