Comparison of anatomical, functional and regression methods for estimating the rotation axes of the forearm

• Published in: Journal of biomechanics Vol. 47; no. 14; pp. 3488 - 3493
• Main Authors: Fraysse, François, Thewlis, Dominic
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 07.11.2014; Elsevier Limited
• Subjects: Adult; Biomechanical Phenomena - physiology; Cross-talk; Elbow; Estimates; Female; Flexion–extension; Forearm; Forearm - anatomy & histology; Forearm - physiology; Humans; Joint kinematics; Male; Methods; Models, Biological; Physical Medicine and Rehabilitation; Pronation - physiology; Pronation–supination; Range of Motion, Articular - physiology; Regression Analysis; Reproducibility of Results; Rotation; Supination - physiology; Upper limb; Forearm; Cross-talk; Pronation–supination; Upper limb; Joint kinematics; Flexion–extension; Elbow
• ISSN: 0021-9290; 1873-2380; 1873-2380
• DOI: 10.1016/j.jbiomech.2014.09.003

Numerous methods exist to estimate the pose of the axes of rotation of the forearm. These include anatomical definitions, such as the conventions proposed by the ISB, and functional methods based on instantaneous helical axes, which are commonly accepted as the modelling gold standard for non-invasive, in-vivo studies. We investigated the validity of a third method, based on regression equations, to estimate the rotation axes of the forearm. We also assessed the accuracy of both ISB methods. Axes obtained from a functional method were considered as the reference. Results indicate a large inter-subject variability in the axes positions, in accordance with previous studies. Both ISB methods gave the same level of accuracy in axes position estimations. Regression equations seem to improve estimation of the flexion–extension axis but not the pronation–supination axis. Overall, given the large inter-subject variability, the use of regression equations cannot be recommended.