How Many Trials Is Enough To Access Balance On The Biodex Balance System?

While the Biodex Balance System (BBS) proved to be a reliable apparatus for testing balance, there is lacking evidence on the number of familiarization trials the subject must undergo before being tested, especially when lower stability levels are used on the BBS. The goal of this study was to determine after how many attempts the result of the balance test on the BBS stabilize. The sample consisted of 66 boys (13.42±0.50 years old) and 57 girls (13.39±0.49 years old) not active in sports. The subjects underwent the Postural Stability Test three times and the Overall Stability Index variable of the BBS was examined. In the analysis the results were separately examined for boys and girls using the t-test. Significant differences were found in all three measurements for boys while for girls there was no significant difference between the second and third measurement. The results of this study indicate that, for boys of this age, the results did not stabilize through the three trials conducted which could mean a need for more than three attempts so the negative effects of familiarization could be avoided. For girls it seems that the result stabilized at the second trial which could indicate that only one trial is needed for them to familiarize themselves with the test. These findings can be important for future studies with a similar female sample to save time and conduct just one test trial before the actual testing, since testing balance on the BBS requires a significant amount of time.