Criterion validity and reliability of a new algorithm to detect jump performance in women’s volleyball players

Abstract

The limitation of tracking systems to assess short high intensity efforts has led to an exponential growth of inertial measurement units (IMU), capable of recording jumps at a very high sampling rate. However, the validity and reliability of each of them should be tested. This study aimed to assess the criterion validity and reliability of a new algorithm to detect jump performance in professional women’s volleyball players during training using an IMU. A total of 1581 jumps performed by 13 players (17.31 ± 7.34 years’ experience, and 6.77 ± 7 years playing in the first league) were video recorded during two volleyball training sessions. Data were recorded with Realtrack Systems IMU (WIMU PRO™, RealTrack Systems, Almeria, Spain), and extracted data were compared against a video system (Sony HDR-CX240 high-definition camera, Sony Corporation, Tokyo, Japan) using an observational procedure (ICC = 0.99). The results showed that WIMU PRO™ identified 1569 from the total of 1581 jumps performed (i.e. 99.24%). Therefore, this wearable device proved to have excellent jump count accuracy in top-level women’s volleyball players, making its use feasible in this sport context. This finding supports the use of this IMU as a valid method to guide the monitoring of jump training load.