Differences in static postural control between top level male volleyball players and non-athletes

It is argued that elite athletes often demonstrate superior body balance. Despite the apparent significance of perfect balance ability in volleyball, little is known about the specific nature of postural control adjustments among first-rate volleyball competitors. This study compared postural performance and strategies in quiet stance between world vice-champions and young, healthy, physically active male subjects. The center-of-pressure (COP) signals recorded on a force plate were used to compute several measures of sway. In both axes of movement, athletes had lower COP range, but not its standard deviation and higher COP speed and frequency than controls. These findings indicate that postural regulation in athletes was more precise and less vulnerable to external disturbances which support optimal timing and precision of actions. Postural strategies in athletes standing quietly were similar to those exhibited by non-athletes performing dual tasks, demonstrating a significant effect of sport practice on changes in postural control. In anterior-posterior axis, athletes displayed a much higher COP fractal dimension and surprisingly lower COP-COG frequency than controls. This accounts for their high capacity to use diversified postural strategies to maintain postural stability and suggests a reduced contribution of proprioception to save this function for carrying out more challenging posture-motor tasks.