Concurrent Validity and Inter-Rater Reliability of Hand-Held Measurements of Maximal Sprint Speed

Abstract

Background: Maximal sprinting speed (MSS) is an essential component of success in many sports. Currently, many systems are used to accurately evaluate athletes’ MSS, including laser or radar guns, single- or dual-beam photocells, high-speed cameras, and high-frequency global positioning systems. However, the cost of these devices may be an obstacle to their implementation into practice. The least expensive but most likely less accurate alternative method of MSS evaluation is the hand-held time measurement of a 30m flying-start sprint. Therefore, the aim of the study was to assess the concurrent validity and inter-rater reliability o the hand-held method of MSS measurement. Materials and Methods: The study involved 3 experienced raters and 18 amateur runners. Runners performed 2-3 trials of the 30m maximal flying-start sprint. In total, 40 observations were collected. Each sprint time was measured simultaneously by raters using a hand-held stopwatch and an electronic timing system. Criterion validity (hand-held vs. electronic timing) was assessed using linear regression analysis. Inter-rater reliability between hand-held timers was evaluated using interclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change (MDC). Results: Results showed that single and average hand-held methods are affected by -0.17 to -0.07m·s-1 (-2.5 to -1.6%) and -0.12m·s- 1 (-1.7%) errors, respectively. Linear regression analysis parameters (free parameter not statistically significant, directional coefficient 0.994-1.057, standard error of estimation 0.073-0.125, R2 0.981-0.994) indicated statistically excellent absolute agreement between a hand-held (single and average) and electronic timing. ICCs of 0.980-0.994, SEM of 0.12m·s-1 (1.87%), and MDC of 0.34m·s-1 (5.18%) indicated statistically excellent absolute agreement and consistency for single and average measurements between hand-held timers. Conclusion: The proposed manual method of MSS measurement underestimates athletes’ speed performance. Moreover, the hand-held 30m flying-start sprint time measurement is affected by a 2% error, and a minimum 5% time change in an individual athlete demonstrates that the change is not simply attributable to measurement error.