Publication Date
1-13-2026
Document Type
Article
Organizational Units
Daniel Felix Ritchie School of Engineering and Computer Science, Mechanical and Materials Engineering, Center for Orthopaedic Biomechanics
Keywords
Glenohumeral joint center of rotation, Optical motion capture, Bi-plane fluoroscopy, Predictive methods, Soft tissue artifact
Abstract
Accurate estimation of the glenohumeral joint center of rotation is critical for biomechanical modeling of shoulder motion. This study evaluated the accuracy of three predictive methods for estimating glenohumeral joint center of rotation using optical motion capture, compared against a benchmark derived from synchronous bi-plane fluoroscopy. Five healthy adults performed shoulder abduction, flexion, and external rotation in 90° abducted and adducted positions. Root mean square error and axial errors were calculated across the full range of motion. Results showed that none of the predictive methods met clinically acceptable thresholds, with absolute error exceeding 10 mm and axial errors surpassing ±5 mm. Error increased significantly with humeral elevation beyond 60° but remained stable during rotational movements. The inclusion of technical markers slightly reduced axial error but did not substantially improve overall accuracy, likely due to soft tissue artifact. Directional axial errors revealed consistent biases, with the acromion method tending to produce anterior, medial, and superior errors. These findings suggest that predictive methods may be suitable for low-elevation tasks, such as gait, but are unreliable for high-elevation activities like overhead sports. The study highlights the importance of evaluating center of rotation estimation across full motion ranges and suggests that future work should explore humeral marker placement and functional methods to mitigate soft tissue artifact and improve accuracy. Validating reliable optical motion capture-based methods against bi-plane fluoroscopy will enhance consistency and comparability in shoulder biomechanics research.
Copyright Date
1-22-2026
Copyright Statement / License for Reuse
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Rights Holder
Julia A. Dunn, Ola Alsaadi, Kevin Shelburne, and Michelle B. Sabick
Provenance
Received from Elsevier
File Format
application/pdf
Language
English (eng)
Extent
8 pgs
File Size
4.66 MB
Publication Statement
Copyright is held by the Authors. User is responsible for all copyright compliance. This article was originally published as
Dunn, J. A., Alsaadi, O., Shelburne, K., & Sabick, M. B. (2026). Accuracy of Glenohumeral Joint Center of Rotation Estimates Using Traditional Motion Capture Versus Bi-Plane Fluoroscopy. Journal of Biomechanics, 197. https://doi.org/10.1016/j.jbiomech.2026.113168
Publication Title
Journal of Biomechanics
Volume
197
First Page
113168
ISSN
0021-9290
PubMed ID
41576664
Recommended Citation
Dunn, Julia A.; Alsaadi, Ola; Shelburne, Kevin; and Sabick, Michelle B., "Accuracy of Glenohumeral Joint Center of Rotation Estimates Using Traditional Motion Capture Versus Bi-Plane Fluoroscopy" (2026). Mechanical and Materials Engineering: Faculty Scholarship. 35.
https://digitalcommons.du.edu/mat_mech_eng_faculty/35
https://doi.org/10.1016/j.jbiomech.2026.113168