May 1st, 2024: New research on the repeatability of gait outcomes in patients with knee osteoarthritis using markerless motion tracking has just been published! The lead author, Jereme Outerleys, conducted this research at the Queen's University Human Mobility Research Lab using Theia3D to measure and analyze gait across multiple subjects. The full publication can be found in the Journal of Biomechanics.
Abstract
Motion analysis has seen minimal adoption for orthopaedic clinical assessments. Markerless motion capture solutions, namely Theia3D, address limitations of previous methods and provide gait outcomes that are robust to clothing choice and repeatable in healthy adults. Repeatability in orthopaedic populations has not been investigated and is important for clinical utility and adoption. The purpose of this study was to evaluate the repeatability of Theia3D for gait analysis in a knee osteoarthritis population. Ten orthopaedic patients with knee osteoarthritis underwent gait analysis on three visits, with an average of 8 days between. Participants were recorded during one-minute overground walking trials at self-selected typical and fast speeds by 8 synchronized video cameras. Video data were processed using Theia3D. Intraclass correlations were used to examine the repeatability of temporal distance metrics as well as segment lengths of the underlying kinematic model. Inter-trial and inter-session variability of lower extremity joint angles were estimated for each point of the gait cycle. Intraclass correlations were greater than 0.98 for all temporal distance metrics for both speeds. Lower body segment lengths had intraclass correlations above 0.90. Participant average joint angle waveforms displayed consistent patterns between visits. The average inter-trial and inter-session variability in joint angles across speeds were 1.17 and 1.45 degrees, respectively. The variability in joint angles between visits was less than typically reported for marker-based methods. Gait outcomes measured with Theia3D were highly repeatable in patients with knee osteoarthritis providing further validation for its use in clinical assessment and longitudinal studies.
The figure above includes representative participant data showing +/- 1 standard deviations of mean joint angles for each visit. This participant had severe medial OA in their right knee with a KL score of 4. Only data from the right leg is shown for the self-selected typical walking speed. In general, mean joint angle waveforms across participants displayed consistent patterns between visits. The average inter-trial and inter-session variability in joint angles across self-selected typical and fast walking speeds were 1.17 and 1.45 degrees, respectively.
If you're interested in more details about this study, check out the full online publication.
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