Metrological Characterization of a Jump Height Measurement Procedure Based on Inertial Sensors

Inertial measurement units (IMUs) have become increasingly valuable tools for monitoring human movements, offering compact and portable solutions for athletic performance analysis. This study aims to metrologically characterize the K-AI wearable device for measuring vertical jump height in professional athletes. The authors developed and validated an algorithm using the K-AI wearable IMU device (K-Sport, Fano, Italy) with data collected on non-athletes and professional basketball players. The jump height measurements obtained from the vertical acceleration of the IMU device were compared to a reference system using video analysis with the Nikon D7200 camera. While the study included primarily non-athletes, it also involved professional basketball players to evaluate the performance of the algorithm in real-world sports environments. The results indicate a mean residual difference of -0.055 m and a standard deviation of 0.068 m, with a strong positive correlation between the two devices (ρ=0.88). However, the Bland-Altman analysis highlights a linear systematic error that increases at greater jump height. This trend suggests that the IMU device estimates lower jump height values than the reference system. This limitation underscores the need for a calibration model to correct systematic deviations to improve the device applicability in the athletic performance assessment.