Sway Balance Mobile Application: Reliability, Acclimation, and Baseline Administration.

OBJECTIVES

To describe historic baseline session administration practices, to assess the utility of a practice trial (an acclimation trial) before the official balance session, and to examine the within-session reliability of the Sway Balance Mobile Application (SBMA).

DESIGN

Retrospective observational study.

SETTING

Middle schools, high schools, and colleges across the United States.

PARTICIPANTS

More than 17 000 student-athletes were included in the Sway Medical database with 7968 individuals meeting this study's inclusion criteria.

INDEPENDENT VARIABLES

The Sway Medical database included the following subject characteristics for each student-athlete: age, sex, weight, and height.

MAIN OUTCOME MEASURES

Balance assessment score generated by the SBMA.

RESULTS

Variable administration practices with significant differences between baseline session averages across methods were found. Individuals who performed an acclimation trial had a significantly higher baseline session average than those who did not. Within-session reliability estimates were in the low to adequate range (r = 0.53-0.78), with higher estimates found for 2 consecutive baseline tests (r = 0.75-0.78).

CONCLUSIONS

For maximum clinical utility, a standardized protocol for postural control baseline acquisition is necessary. Acclimation trial should be administered before a baseline session to minimize variability, especially with only 1 to 2 baseline tests. The highest reliability was observed across 2 consecutive baseline tests within the same baseline session. We suggest obtaining baseline balance measurements with an acclimation trial followed by a baseline session with 2 baseline tests. Prospective studies are required for validation.