Calculating the axes of rotation for the subtalar and talocrural joints using 3D bone reconstructions

W.C.H., Parr; H.J., Chatterjee; C., Soligo

doi:10.1016/j.jbiomech.2012.01.011

« Previous Next »Journal of Biomechanics
Volume 45, Issue 6 , Pages 1103-1107, 5 April 2012

Calculating the axes of rotation for the subtalar and talocrural joints using 3D bone reconstructions

W.C.H. Parr
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Research Department of Genetics, Evolution and Environment, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
- Department of Palaeontology, Natural History Museum, London SW7 5BD, UK
- Corresponding author at: Rm 558, School of Biological, Earth and Environmental Sciences, Biological Sciences building (D26), University of New South Wales(UNSW), Sydney, NSW 2052, Australia. Tel.: +61 405658783.
H.J. Chatterjee
- Research Department of Genetics, Evolution and Environment, Division of Biosciences, University College London, Gower Street, London WC1E 6BT, UK
C. Soligo
- Department of Anthropology, University College London, 14 Taviton Street, London WC1H 0BW, UK

Accepted 10 January 2012. published online 30 January 2012.

Abstract

Orientation of the subtalar joint axis dictates inversion and eversion movements of the foot and has been the focus of evolutionary and clinical studies for a number of years. Previous studies have measured the subtalar joint axis against the axis of the whole foot, the talocrural joint axis and, recently, the principal axes of the talus. The present study introduces a new method for estimating average joint axes from 3D reconstructions of bones and applies the method to the talus to calculate the subtalar and talocrural joint axes. The study also assesses the validity of the principal axes as a reference coordinate system against which to measure the subtalar joint axis. In order to define the angle of the subtalar joint axis relative to that of another axis in the talus, we suggest measuring the subtalar joint axis against the talocrural joint axis. We present corresponding 3D vector angles calculated from a modern human skeletal sample. This method is applicable to virtual 3D models acquired through surface-scanning of disarticulated ‘dry’ osteological samples, as well as to 3D models created from CT or MRI scans.

Keywords: Ankle joint axis, Subtalar joint axis, 3D modelling, Principal axes