Bruening Dustin A, Crewe Ashlie N, Buczek Frank L
Health, Nutrition, and Exercise Science Department, University of Delaware, Newark, DE, USA.
Clin Biomech (Bristol). 2008 Dec;23(10):1299-302. doi: 10.1016/j.clinbiomech.2008.08.005. Epub 2008 Oct 10.
Conventional motion analysis studies define the ankle joint center as the midpoint between the most medial and lateral aspects of the malleoli, yet research points toward a more distal joint center location. The purpose of this study was to develop and evaluate an anatomically based correction that would move the conventional ankle joint center to a more accurate location.
Lower extremity radiographs from 30 pediatric patients were analyzed retrospectively. An offset between the conventional and more accurate ankle joint centers was measured and correlated to other common anatomical measures based on conventional skin mounted marker positions. The best correlated measure was used to define a simple correction factor, which was subsequently evaluated by its effect on six degree-of-freedom ankle joint translations during normal gait (n=8).
Shank length was found to have the highest bivariate linear correlation (r=0.89) with the offset. Adjusting the ankle joint center using a percentage of shank length (2.7%) was also as accurate as the regression equation in predicting offset (mean error 0.6mm, or 6% offset). Adjusting the ankle joint center using this simple percentage resulted in a 25% reduction in mean ankle joint translations during normal gait.
The accuracy of the ankle joint center can be increased through a simple, anatomically based correction. This correction may prove beneficial in some kinematic and kinetic applications requiring increased anatomical fidelity.
传统的运动分析研究将踝关节中心定义为内外踝最内侧和最外侧之间的中点，但研究表明关节中心位置更靠下。本研究的目的是开发并评估一种基于解剖学的校正方法，将传统的踝关节中心移至更准确的位置。
回顾性分析30例儿科患者的下肢X线片。测量传统踝关节中心与更准确的踝关节中心之间的偏移，并根据传统的皮肤表面标记位置将其与其他常见的解剖学测量值进行关联。使用相关性最强的测量值来定义一个简单的校正因子，随后通过其对正常步态（n = 8）期间六自由度踝关节平移的影响来评估该因子。
发现小腿长度与偏移的双变量线性相关性最高（r = 0.89）。使用小腿长度的百分比（2.7%）调整踝关节中心在预测偏移方面与回归方程一样准确（平均误差0.6mm，即偏移的6%）。使用这个简单的百分比调整踝关节中心可使正常步态期间踝关节平均平移减少25%。
通过一种简单的、基于解剖学的校正方法可以提高踝关节中心的准确性。这种校正可能在一些需要提高解剖学逼真度的运动学和动力学应用中被证明是有益的。
