Inter-rater reliability of trained and untrained raters for measuring jump height with the MyJump app

Smartphone apps have been very popular among researchers, coaches and clinicians. The aim of this study was to analyze the inter-rater reliability of trained and untrained raters of the iOs app MyJump. Eighteen participants completed eight counter-movement jumps (CMJ) each (n=144) which were recorded using the app. In order to examine inter-rater reliability derived from raters’ experience, independent assessments were obtained by an untrained rater and two trained raters of the same recordings. Results showed very high agreement between trained raters (ICC=0.982, α=0.991) and between trained and untrained raters (ICC=0.984, α=0.992). Bland-Altman plots depicted negligible bias between both types of raters. Finally, very good internal consistency was found, regardless of experience (α from 0.995 to 0.997 and CV from 1.1 to 1.4%). This study have shown no significant difference in performance of trained and untrained raters of MyJump, and therefore no special training must be observed for an accurate use of the app.