School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
J Biomech. 2012 Apr 5;45(6):1103-7. doi: 10.1016/j.jbiomech.2012.01.011. Epub 2012 Jan 28.
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.
跟骨下关节轴的方向决定了足的内翻和外翻运动，多年来一直是进化和临床研究的焦点。先前的研究已经测量了跟骨下关节轴与整个足的轴线、距下关节轴以及最近的距骨主轴线的关系。本研究介绍了一种从骨骼 3D 重建中估计平均关节轴的新方法，并将该方法应用于距骨来计算跟骨下关节轴和距下关节轴。该研究还评估了主轴线作为参考坐标系来测量跟骨下关节轴的有效性。为了定义跟骨下关节轴相对于距骨中另一个轴的角度，我们建议测量跟骨下关节轴与距下关节轴的夹角。我们给出了从现代人类骨骼样本计算出的相应的 3D 向量角度。该方法适用于通过对脱臼“干”骨骼样本进行表面扫描获得的虚拟 3D 模型，以及通过 CT 或 MRI 扫描创建的 3D 模型。
