Reliability and validity of GPS-embedded accelerometers for the measurement of badminton specific player load.

Abstract

Objectives: The aim of this study was twofold, firstly to assess the reliability of the VX Sport Log GPS-based accelerometer, and secondly the validity of the same device compared to a Catapult Optieye S5 (considered a gold standard) recording at 100 Hz. Design & Methods: A total of 15 participants were recruited to take part in two separate trials of a Badminton specific endurance test. Reliability and validity assessments were conducted using coefficients of variation, intra-class correlation coefficient, Bland-Altman plots per axis (Vertical, Antero-posterior and Medio-lateral) and for vector magnitude (player load). Results: Reliability results demonstrate high levels of agreement between devices. Validity results also demonstrate high levels of agreement. However, there were issues with sample rate agreement between manufacturers of 0.25%. Conclusion: This study re-emphasises the need for sports utilising GPS-based accelerometers to conduct reliability and validity studies to ensure the consistency between data collection systems.