RELIABILITY OF A DIGITAL METHOD TO DETERMINE FRONTAL AREA OF A CYCLIST

Abstract

Eight cyclists were photographed with a digital camera for three trials while positioned on their own bicycle wearing their helmet. The positions were different from each other and described as: hands on the brake hoods; hands below the curve of the brakehoods on the handlebars; and using aerobars. Twenty four trials were digitized by two different individuals three times to estimate the inter- and intra-rater reliability of the method. The Intraclass Correlation Coefficient (p < 0.05) value for the intra-rater (test-retest) reliability was ICC = .993; for inter-rater consistency the ICC = .976. There were significant differences (p < 0.05) between digitizers and between trials apparently due to a learning effect that disappeared by the third trial. Due to small differences between digitizers and trials, caution is recommended when considering use of this method.