Clinical applicability of using spherical fitting to find hip joint centers
Clinical applicability of using spherical fitting to find hip joint centers
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DOI：
10.1016/j.gaitpost.2004.08.004
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发表时间：
2005-10-01
期刊：
影响因子：
2.4
通讯作者：
Richards, JG
中科院分区：
文献类型：
--
作者：
Hicks, JL;Richards, JG
功能或球体拟合方法已被提出作为传统预测方法的替代方案，以根据ASIS间宽度定位髋关节中心。在功能方法中，大腿上的标记的移动被拟合到中心与髋关节中心重合的球体。本研究的第一个目的是确定所需的参数，允许一个球拟合方法的准确应用。本研究中检查的参数包括：（1）屈曲-伸展和外展-内收的运动范围，（2）用于将球体拟合到数据的特定算法，（3）在大腿上放置标记的方法，以及（4）用于生成点的运动类型，步行或站立腿运动（SLM）试验。这一目标是通过计算机模拟和临床数据来解决的。第二个目标是在一组9名人类受试者中比较功能方法与传统预测方法的准确性。将两种方法的髋关节中心位置估计值与超声确定的髋关节中心标准进行比较，并比较线性误差和沿沿着每个轴的误差。计算机模拟的结果表明，需要迭代算法，使用导数的方法产生稍微更准确的结果。临床结果表明，功能方法与站立腿运动试验产生的髋关节中心估计（1.34厘米）与预测方法（2.16厘米）的误差显着较小。此外，功能方法的髋关节误差范围较小。如果需要高关节中心准确度，或者在以肥胖或骨盆不对称为特征的人群中，受试者特异性和与功能方法的解剖标志特征的独立性可能会提供更准确的结果。(c)2004 Elsevier B. V.保留所有权利。
The functional or sphere-fitting method has been proposed as an alternative to the traditional predictive approach to locating hip centers based on inter-ASIS breadth. In the functional approach, the movement of a marker on the thigh is fit to a sphere whose center coincides with the hip joint center. The first objective of this study was to determine the required parameters that allow an accurate application of a sphere-fitting method. The parameters examined in this study included: (1) the range of motion in flexion-extension and abduction-adduction, (2) the specific algorithm used to fit a sphere to the data, (3) the method of placing markers on the thigh, and (4) the type of motion used to generate points, either walking or a standing leg motion (SLM) trial. This objective was addressed with a computer simulation and clinical data. The second objective was to compare the accuracy of the functional method to the traditional predictive approach in a group of nine human subjects. The location of the hip center estimates from both methods were compared to an ultrasound-determined hip center standard, and linear errors and errors along each axis were compared. Results from the computer simulation indicated that an iterative algorithm is needed, with a method using the derivative yielding slightly more accurate results. Clinical results indicated that the functional method with a standing leg motion trial produced significantly smaller errors in hip joint center estimates (1.34 cm) versus the predictive method (2.16 cm). In addition, the range of error across hips was smaller for the functional method. If high joint center accuracy is needed or in populations characterized by obesity or pelvic asymmetries, the subject specificity and independence from anatomical landmarks characteristic of the functional method would likely provide more accurate results. (c) 2004 Elsevier B.V. All rights reserved.