comparison of two methods for in vivo estimation of the glenohumeral joint rotation center (gh-jrc) of the patients with shoulder hemiarthroplasty比较两种方法的体内盂肱关节旋转中心的估计(gh-jrc)患者肩膀心脏血管.pdfVIP

Comparison of Two Methods for In Vivo Estimation of the Glenohumeral Joint Rotation Center (GH-JRC) of the Patients with Shoulder Hemiarthroplasty 1 1 2 2 Ali Asadi Nikooyan *, Frans C. T. van der Helm , Peter Westerhoff , Friedmar Graichen , Georg Bergmann2, H. E. J. (Dirkjan) Veeger1,3 ´ ¨ 1 Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands, 2 Julius Wolff Institut, Charite, Universitatsmedizin, Berlin, Germany, 3 Research Institute MOVE, VU Amsterdam, Amsterdam, The Netherlands Abstract Determination of an accurate glenohumeral-joint rotation center (GH-JRC) from marker data is essential for kinematic and dynamic analysis of shoulder motions. Previous studies have focused on the evaluation of the different functional methods for the estimation of the GH-JRC for healthy subjects. The goal of this paper is to compare two widely used functional methods, namely the instantaneous helical axis (IHA) and symmetrical center of rotation (SCoRE) methods, for estimating the GH-JRC in vivo for patients with implanted shoulder hemiarthroplasty. The motion data of five patients were recorded while performing three different dynamic motions (circumduction, abduction, and forward flexion). The GH-JRC was determined using the CT-images of the subjects (geometric GH-JRC) and was also estimated using the two IHA and SCoRE methods. The rotation centers determined using the IHA and SCoRE methods were on average 1.4760.62 cm and 2.0760.55 cm away from geometric GH-JRC, respectively. The two methods di