University of Applied Sciences and Arts of Southern Switzerland, Department of Health Sciences, Manno, Switzerland.
Arthrokinematics Research Group, Faculty of Physical Education and Physiotherapy, Department of Experimental Anatomy, Vrije Universiteit Brussel, Belgium.
J Electromyogr Kinesiol. 2014 Oct;24(5):628-35. doi: 10.1016/j.jelekin.2014.05.004. Epub 2014 May 22.
Although a far more stable approach compared to the six degrees of freedom analysis, the finite helical axis (FHA) struggles with interpretational difficulties among health professionals. The analysis of the 3D-motion axis has been used in clinical studies, but mostly limited to qualitative analysis. The aim of this study is to introduce a novel approach for the quantification of the FHA behavior and to investigate the effect of noise and angle intervals on the estimation of FHA parameters. A simulation of body movement has been performed introducing Gaussian noise on position and orientation of a virtual sensor showing linear relation between the simulated noise and the error in the corresponding parameter. FHA axis behavior was determined by calculating the intersection points of the FHA with a number of planes perpendicular to the FHA using the Convex Hull (CH) technique. The angle between the FHA and each of the IHA was also computed and its distribution was also analyzed. Input noise has an inversely proportional relationship with the angle steps of FHA estimation. The proposed FHA quantification approach can be useful to provide new approaches to researchers and to improve insight for the clinician in order to better understand joint kinematics.
与六自由度分析相比，尽管有限螺旋轴线（FHA）方法更为稳定，但它在健康专业人员之间的解释上存在困难。3D 运动轴的分析已在临床研究中使用，但主要限于定性分析。本研究旨在引入一种新的 FHA 行为量化方法，并研究噪声和角度间隔对 FHA 参数估计的影响。通过在虚拟传感器的位置和方向上引入高斯噪声，模拟身体运动，模拟噪声与相应参数的误差之间存在线性关系。使用凸包（CH）技术，通过计算 FHA 与多个垂直于 FHA 的平面的交点来确定 FHA 轴行为。还计算了 FHA 与每个 IHA 之间的夹角，并对其分布进行了分析。输入噪声与 FHA 估计的角度步长成反比关系。所提出的 FHA 量化方法可用于为研究人员提供新方法，并为临床医生提供更好的关节运动学理解的洞察力。
