ESTIMATION OF THE JUMP HEIGHT FOR THE VOLLEYBALL SPIKE BY A MOBILE IMU UNIT

The maximal jumping height can be considered as a determining factor of spike as well as overall game performance. The purpose of this study was to develop and validate a mobile device based on inertial sensors as an alternative for in-field diagnostics. 23 female and male volleyball players performed 106 spikes with an IMU fixed at each ankle. An OptojumpNextTM system (OJ) served as reference. Interclass correlation analysis computed a coefficient of r=.995. Bland-Altman-plot showed 95% limits of agreement between 2.9cm and -1,2cm. Hence, the mobile IMU device determines jumping height in real competition conditions with an accuracy of approximately ±2cm. We consider this as acceptable for application in volleyball training, e.g., but further effort is necessary to optimize the detection algorithms to achieve higher accuracy