ABSTRACT
Introduction:
The numerous instruments used to measure jump height use different technologies and calculations that can provide variable results.
Objective:
This study compared the countermovement jump (CMJ) height assessed with a wearable 3D inertial measurement unit (IMU), using flight time and the numerical integration method with a force platform and photocells.
Methods:
Forty CMJs were analysed, starting from an upright standing position with the hands placed on the waist. Twenty healthy volunteers completed 2 CMJs, which were simultaneously assessed using an IMU placed on the subject's sacrum, a force platform (considered the gold standard method) and photocells. The maximum height of each CMJ was measured.
Results:
The results showed a significant overestimation (p<0.001) in jump height for the IMU using the numerical integration method when compared to the force platform (+7 cm). Excellent intraclass correlation coefficients (ICCs) were obtained with the flight time equations for the different types of measurement equipment. Fair to good ICCs were obtained with the IMU using the numerical integration method and force platform.
Conclusion:
In conclusion, the jump height obtained with the IMU using the numerical integration method showed the poorest agreement compared to the force platform. Level of evidence III; Prospective comparative study.
Keywords:
Biomechanics; Instrumentation; Acceleration