PURPOSE: It is well known that postural stability is influenced by visual stimuli. The influence of saccadic eye movement on postural control has been described, however, a specific response of different body segments has not been studied yet. Therefore, the aim of this study was to assess the effect of horizontal and vertical saccadic eye movements on postural stability with specific focus on upper trunk, lower trunk and lower limbs movement variability and complexity. METHODS: Eighteen elderly participants (age 70.3 ± 7.7 years) stood in bipedal stance in three visual conditions - horizontal saccades, vertical saccades and fixation. Accelerometers were attached to their lower back, sternum and shanks. Movement variability of each body segment was described by root-mean-square and sample entropy of acceleration. RESULTS: The results of the present study revealed significant influence of saccadic eye movements on anterior-posterior and vertical shanks, and vertical lower trunk movement variability described by root-mean-square. CONCLUSIONS: The correlations between results of the observed segments showed segment-specific variability patterns but generalised complexity pattern.

Palacky University Olomouc Faculty of Physical Culture Olomouc Czech Republic