A Reliability Study for Standing Functional Reach Test Using Modified and Traditional Rulers

Abstract

The purposes of the study were (1) to estimate the standing reach distance, test-retest, and interrater reliability of the functional reach test using traditional and modified rulers and (2) to evaluate the difference in the scores based on one trial, the mean of two or of three trials. Sixty-four individuals ( M age = 36.3 yr., SD = 19.5, range = 19 to 70 years; 24 men, 40 women) volunteered to participate. Differences in measurements were examined. The intraclass correlation coefficient (ICC) was used to assess the test-retest and interrater reliability. Analysis indicated that the reach score measured by the rulers were not statistically significantly different, but the three measurements were significantly different. Reliability estimates were similar for the two mean scores, the mean of two trials (ICC2,2 = 0.87–1.00) or three trials (ICC2,3 = 0.89–1.00). The standard error of measurement (SEM) was always smaller when the modified ruler was used than when the traditional ruler was used. Performance with the modified ruler is an alternative to that with a traditional ruler. The mean of two trials as a measure of performance of reach distance when standing is recommended with either ruler.