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Updated: Jul 1, 2026
An Inertial Measurement Unit Based Method to Estimate Hip and Knee Joint Kinematics in Team Sport Athletes on the Field
Published on: May 26, 2020
Inertial measurement units are comparable to motion capture for measuring intersegmental spinal angular velocities in
Tena Ursini1, Hilary Clayton2, David Levine3
1Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Equine Performance and Rehabilitation Center, University of Tennessee, Knoxville, TN.
Objective:
To compare inertial measurement unit (IMU)-derived intersegmental spinal motion data with measurements obtained from a marker-based motion-capture system.
Methods:
4 horses were instrumented with custom marker clusters incorporating a 3-D-printed base designed to secure the IMU, ensuring both systems recorded data from the same anatomical location and orientation. A total of 3,737 paired time points across 37 gait cycles were analyzed. Agreement in intersegmental angular velocities across 3 planes of motion was evaluated using Bland-Altman analysis and intraclass correlation coefficients.
Results:
Bland-Altman analysis demonstrated no significant systematic bias between methods. Intraclass correlation coefficients indicated excellent agreement in 7 of 9 comparisons (r = 0.964 to 0.991) and good agreement in the remaining 2 comparisons (r = 0.854 and 0.875).
Conclusions:
IMUs provide a valid alternative to marker-based motion-capture systems for measuring intersegmental angular velocities in horses.
Clinical Relevance:
Strong agreement between IMU and motion-capture data supports the use of IMUs for assessing topline function in nonlaboratory, clinically relevant settings.
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