Publication details
Intra- and Inter-rater Reliability of MyJump2 App in Measuring the Speed of Specific Karate Techniques
| Authors | |
|---|---|
| Year of publication | 2026 |
| Type | Article in Periodical |
| Magazine / Source | Ido Movement for Culture Journal of Martial Arts Anthropology |
| MU Faculty or unit | |
| Citation | |
| web | https://www.imcjournal.com/index.php/en/2248-intra-and-inter-rater-reliability-of-myjump2-app-in-measuring-the-speed-of-specific-karate-techniques |
| Keywords | application; experience of the rater; karate kata; smartphone; specific techniques |
| Attached files | |
| Description | Background. The speed of execution of specific techniques is a crucial component of athletic performance in karate kata. Accurate diagnostics of these abilities is essential for practice, therefore, we evaluated the reliability of the smartphone-based application MyJump2. Problem and aim. This study aimed to examine the intra- and inter-rater reliability of MyJump2 in measuring the execution time of sport-specific movements of top-level youth karatekas by two raters. Methods. Participants (12 female, 15.53 ± 1.13 years) completed selected techniques that were video recorded using iPhone SE2020, and the execution time was obtained with MyJump2. Intra-rater reliability was determined by rating the same videos by an experienced and an inexperienced rater on two occasions. Inter-rater reliability was determined by comparing the ratings of the two raters. Results. Intraclass correlation coefficient (ICC) revealed excellent intra-rater reliability regardless of the technique or experience of the rater (r?0.90; p?0.001). Correlations were high for the experienced rater (ICC=0.97-0.99) with mean differences 2.9-4.5 ms (0.36-1.58%) and the inexperienced rater (ICC=0.94-0.98) with mean differences 3.1-6.5 ms (1.10-1.93%). An excellent inter-rater reliability was proven for all given techniques (r?0.90; p?0.001), producing high correlations (ICC=0.94-0.99) with mean differences 4.4-8.7 ms (0.51-2.57%). We found the lowest differences within the experienced (2.9±2.8, 0.51%) and the inexperienced rater (6.2±7.8, 1.10%), as well as between the raters (4.4±2.9, 0.78%) for the kick-return technique. Conclusions. We conclude that MyJump2 is a reliable and useful tool for measuring the execution time of specific techniques in karate. We proved higher accuracy in measuring kicking techniques and the advantage of prior experience in the rater. |