Abstract
The purpose of this study was compare the postural stability between the deaf and the normal hearing adults, and fing out if the statistically significant difference in measured parametrs does exist. 102 subjects at the age 20-45 years participated in this study. The experimental group consisted of 35 deaf adult subjects with congenital or early childhood deafness.
The control group has been made by 67 normal hearing adult subjects. The postural stability was objectively evaluated by Footscan, the pressure measuring plate..
Nine tests were performed, duration of each test was 30 seconds. The total travelled way expressing the total path the centre of acting pressure travelled during the test and the Romberg ratio were selected as indicators of postural stability.
T-test was used to asses the statistical significance of the differences between the group of deaf adults and normal hearing group. To etimate the influence of individual characteristics of the subjects to their postural stability, the ordinary least squares estimator was used.
Results: The experimental group was on average worse in eight out of nine types of test. The differences were significant at 1% in case of standing on a firm surface with narrow stance, with closed eyes, and at 5% in case of standing on a foam pad with wide stance, with closed eyes.
The estimation results also indicated that there was a significant stronger deterioration of stability due to close eyes in case of deaf adults than in the control group.