Consistency of measurement for FITNESSGRAM skinfold and trunk lift assessments

Abstract

FITNESSGRAM is a widely used fitness assessment for students in grades K-12. Although it is widely used and accepted, prior research indicates that two of the test items may have lower reliabilities than desired. In this study 6 volunteers administered the skinfold and trunk lift subtests to 11middle school students according to the instructions found in the FITNESSGRAM Test Administration Manual. Each administrator was provided with the manual as well as a Slim Guide skinfold caliper to use for administration purposes. After administering the two subtests, intraclass correlation coefficients were found to determine level of absolute agreement between raters, while Pearson correlation coefficients were used when to determine how well a single rater could consistently rank the students in the same or similar order. The results demonstrate a high level of absolute agreement among raters for the triceps skinfold test, ICC(3,6)=.83, as well as a mean Pearson reliability coefficient of r=.92. The results of the calf skinfold measurement also show a high level of absolute agreement, ICC(3,6)=.89,but the mean Pearson coefficient was lower, r=.81suggesting that the skinfold assessment, as presented in FITNESSGRAM, provides a reliable measure of body composition in terms of both absolute agreement among raters as well as consistent rankings within each rater. During the first testing session, the trunk lift test had high levels of absolute agreement among raters, ICC(3,6)=.90. However, there was a decline during the second testing session, ICC(3,6)=.77. Pearson reliability correlation coefficients were also low (mean r=.58) suggesting that single raters had difficulty consistently ranking the students in the same order on this measure.