Unintentional balance destabilization system reliability studies

The extent of neural and muscular response differences to sudden unintentional balance destabilization system (UBDS) compared to command-driven tasks could produce a new measure to explain why some elders who do well in command-driven clinical balance tests experience unintentional falls. This paper presents pilot studies on the reliability that UBDS test environment compared to performing command-driven tasks triggers a characteristic trend in neural and muscular response latencies in humans. Eleven adults 60 years or older participated in this study. Tasks performed included maintaining balance while balance is suddenly perturbed by the UBDS and while performing command-driven sit-to-stand and stand-to- sit tasks. Signals were synchronously recorded from the forehead, the neck and 6 muscle groups of both legs. Each subject visited the lab the following day for repeat test. One way ANOVA was used to determine the main differences in neural and muscular response latencies between repeat trials during both UBDS and command-driven test scenarios.Graphical analysis was also used to elucidate latency trend between test-retest trials.Test results show consistent significant prolonged response latency differences when destabilization is caused by UBDS test environment than while performing any of the command-driven tests. Within each test scenario for UBDS at 95% confidence interval test-retest p value for latency variable was less than 0.000001 except for one person, for both command-driven tasks there were no significant latency differences, at 95% confidence intervals p values were greater than 0.8 except for one at 001.The trends were depicted graphically also.The results demonstrated test-retest reliability thatUBDS triggers prolonged response latency when balance is suddenly perturbed, a variable that is not detectable during command-driven tests.