RELIABILITY AND VALIDITY OF AN OBJECTIVE MEASURE OF SITTING BALANCE.

Abstract

Purpose/Hypothesis: Available balance measures are primarily for people who can stand and are not valid for those who are primarily non-ambulators. The purpose of this study was to assess the reliability and validity of an objective measure of sitting balance. Number of Subjects: Participants were 14 primarily non-ambulatory older adults (mean age 81.5 years), 11 content expert clinicians, 4 raters who were PT students and 2 geriatric experienced PTs. Materials/Methods: Older participants performed 11 tasks ranging from quiet sitting to a sit to stand transfer, with 5 repeated on foam for a total of 16 items. The test was scored by student and experienced raters. Participants rated their steadiness on each item using a 5-point scale. Raters viewed video of the original testing and rescored participants performance to determine reliability. Content experts rated the importance of each item using a 5-point scale and made suggestions for improvement. Data analysis included ICCs, one way ANOVA, paired sample t-tests, Chronbachs alpha, and Pearson correlations. Results: Intrarater reliability of the raters ranged from ICC=.86 to 1.0. Interrater reliability for total scores was ICC=.97. There were no differences in the mean rating for each item and for the total score between the student and experienced raters. The entire tool demonstrated internal consistency (Chronbachs alpha=.76), but two items had an alpha below the desired level of .4. Most (61%) participants considered themselves fairly steady when performing the test as a whole. There was a strong relationship (r=.84, p=.001) between total score of self-assessed steadiness and total score on the balance tool. The mean rating of importance for each item ranged from 2.30 to 3.82. In general, the experts felt that items on foam were not useful. Conclusions: The 16-item tool appears to be reliable for assessing sitting balance in primarily non-ambulatory subjects. It demonstrates excellent intra and interrater reliability which is not dependent on rater experience. The tool appears to have good face and content validity for assessing balance in primarily non-ambulatory subjects. Based on the findings the tool will be modified to eliminate redundant items and items with poor internal consistency. Further study is necessary to determine reliability and validity of the revised 10-item tool. Clinical Relevance: This study demonstrates that this measure of sitting balance may be an effective tool for individuals who are primarily non-ambulatory. The future 10-item tool may provide clinicians with an objective measure of sitting balance and should be used in clinical practice to measure and monitor changes in sitting balance over time.