Van Alsenoy Ken K, De Schepper Joris, Santos Derek, Vereecke Evie E, D'Août Kristiaan
J Am Podiatr Med Assoc. 2014 May;104(3):238-46. doi: 10.7547/0003-0538-104.3.238.
Locating the position of the subtalar joint axis can be a predictive clinical variable in biomechanical analysis and a valuable tool in the design of functional foot orthoses. Before testing Kirby's palpation technique to locate the subtalar joint axis in cadavers, it was important to develop and test the experimental methods in a mechanical model in which the exact location of the hinge joint can be controlled.
Four testers determined the hinge joint location and moved it through its range of motion, capturing the movement of the joint axis using a kinematic model. The joint axis location was determined and validated by comparing the actual hinge joint location on the mechanical model with the location determined by the palpation technique described by Kirby in 1987 and the location determined by the helical joint axis method using three-dimensional kinematic data.
The overall angles result in mean slopes and intersections of 87° and 92 mm, 86° and 97 mm, 85° and 92 mm, and 88° and 91 mm for testers 1, 2, 3, and 4, respectively. Testers 1 and 3 were able to determine the location to 1° and 1 mm accuracy, tester 2 to 0° and 4 mm, and tester 4 to 2° and 2 mm compared with the kinematic data.
The technique of determining the points of no rotation as described by Kirby could be validated by using a three-dimensional kinematic model to determine the helical axis.
确定距下关节轴的位置在生物力学分析中可能是一个具有预测性的临床变量，并且在功能性足部矫形器的设计中是一种有价值的工具。在测试柯比的触诊技术以在尸体中定位距下关节轴之前，重要的是在一个可以控制铰链接合确切位置的力学模型中开发和测试实验方法。
四名测试者确定铰链接合的位置并使其在其运动范围内移动，使用运动学模型捕捉关节轴的运动。通过将力学模型上实际的铰链接合位置与柯比在1987年描述的触诊技术所确定的位置以及使用三维运动学数据的螺旋关节轴方法所确定的位置进行比较，来确定并验证关节轴的位置。
对于测试者1、2、3和4，总体角度分别导致平均斜率和交点为87°和92毫米、86°和97毫米、85°和92毫米以及88°和91毫米。与运动学数据相比，测试者1和3能够将位置确定到1°和1毫米的精度，测试者2到0°和4毫米，测试者4到2°和2毫米。
通过使用三维运动学模型来确定螺旋轴，可以验证柯比所描述的确定无旋转点的技术。
