Aim: The study was designed to assess the effects of surface instability in the response of the balance control system in children and youths with visual impairment (BL) and in normally sighted controls (NE).
Materials and methods: The empirical research study involved 80 individuals, aged from 6 to 20 years, with a mean age of 14.37 (±4.68), including 40 blind individuals and a randomly selected control group 40 normally sighted. Stabilometric measurements were performed with the use of the Platform CQ Stab 2P, with eyes open (EO) and closed (EC) on the solid surface, and then, the same procedure was performed on the platform covered with 1-centimetre-thick foam.
Results: Statistical analyses (Wilcoxon matched-pairs test, Mann-Whitney U test) of the results identified during the trials reveal the following findings in the BL group in the EO and EC tests. The results of the foam surface test were higher and the differences were statistically significant in the BL group (sway path EO p = 0.009, EC p = 0.006; mean amplitude EC p = 0.030; mean velocity EO p = 0.009, EC p = 0.006; sway area EO p = 0.017, EC p = 0.009; and number of COP deflections along the sagittal plane EO p = 0.004). No similar correlations were observed in the NE group, except for the mean amplitude EO p = 0.033 and sway area EO p = 0.030. There was one difference between the BL and the NE group for the mean amplitude parameter, p = 0.018, in a solid surface test with open eyes. The results were higher in the BL group.
Conclusions: The present study showed no worse balance in the BL group than in the NE group but worse performance on the foam than without it. It indicates the need to develop body balance skills in blind people by improving their proprioceptive sensitivity. In everyday life and training, blind people should experience exteroceptive stimuli, different textures, and unstable surfaces as much as possible.
Keywords: blind; postural stability; proprioceptive.