Role of vision in static balance in persons with and without visual impairments.

Background: Vision is one of the elements of the system responsible for maintaining static balance. Any visual impairments or conditions hampering the reception of visual stimuli may affect static balance. It would be interesting to identify to what extent people with different degrees of dysfunction and in different conditions are able to compensate for the inability to receive visual stimuli while maintaining balance.

Aim: The aim of this study was to determine the role of the vision in maintaining static balance. This study sought to assess balance and the degree of compensation when the possibility of receiving visual stimuli is limited in persons without visual impairments and persons with varying degrees of visual impairments.

Design: Controlled observational study.

Setting: Main University Laboratory.

Population: The study included 122 individuals, 81 of whom were visually impaired. The participants with visual impairments were divided into three groups according to their levels of disability.

Methods: Subjects performed tests on a stabilographic platform: standing on both feet with eyes open and closed, single right- and left-leg stance with eyes open and closed. The center of pressure path length and the visual inspection indicator were analysed. Significance of differences between the groups regarding the visual inspection indicator and tests performed with eyes open and closed was assessed with the use of the Mann-Whitney U test. The effects and interactions between variables were verified using the ANOVA test for the main effects and factorial designs.

Results: Differences were noted in balance of persons without visual impairments in single-leg stance tests with eyes open and closed as well as when standing on both feet with eyes open and closed. In persons with visual impairment, significant differences were observed in the single left-leg stance test with eyes open and closed only. Testing conditions and disability levels exerted a significant influence on static balance in single-leg tests.

Conclusions: The findings of the study confirm the role of vision in maintaining balance in the context of factors that may affect it, i.e. conditions (eyes open or closed) and possibilities of receiving visual stimuli (disability level).

Clinical Rehabilitation Impact: The significance of the visual effect was noted in single-leg tests. More demanding tests detect compensatory mechanisms of balance more accurately.