The potential of the VIVE Ultimate Tracker in Movement Analysis applications: accuracy of single degree of freedom motions and pelvis motion during gait

Recent advances in wearable motion sensors, particularly inertial measurement units (IMUs), have opened new possibilities for motion analysis, providing a portable and cost-effective alternative to traditional gait analysis systems. While IMUs have by now become well-established orientation trackers, they face significant challenges in estimating position. The VIVE Ultimate Tracker is a wearable IMU-based device embedding an AI-powered dual wide-field-of-view (FOV) camera system providing its 3D position and orientation with respect to an absolute reference system defined by spatial mapping. Although originally designed for gaming purposes, it may represent a promising solution for mobile motion analysis. The study aimed at assessing the accuracy of the VIVE Ultimate Tracker against a camera-based optoelectronic system both in controlled conditions and during gait. Maximum angular and linear displacement errors during planar rotations performed at three different velocities on a 3 DoF hinged plank were 2.13° and 22.2 mm, respectively. When a subject walked at three walking speeds, the maximum pelvis position errors were 44 mm, 21 mm, 11 mm along the antero-posterior, medio-lateral and vertical directions.
Preliminary results suggest the potential of this emerging technology for mobile motion analysis purposes.