title: Evaluation of a new algorithm to determine the hip joint center.
abstract: Accurately locating the hip joint center is a challenging and important step in many biomechanical investigations. The purpose of this study was to test the accuracy and robustness of a "pivoting" algorithm used to locate the hip center. We tested the performance of this algorithm with data acquired by manipulating a ball and socket model of the hip through several motion patterns. The smallest mean errors of 2.2+/-0.2 mm occurred with a circumduction motion pattern, while the largest errors of 4.2+/-1.3 mm occurred with single-plane motion (e.g., flexion/extension). Introducing random noise with an amplitude of 30 mm increased the errors by only 1.3+/-0.5 mm with a circumduction motion pattern. The pivoting algorithm performs well in the laboratory, and further work is warranted to evaluate its performance in a clinical setting.
authors.affiliation: Mechanical Engineering Department, Stanford University, Stanford, CA 94305-5450, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Siston
authors.forename: Scott L
authors.initials: SL
authors.lastname: Delp
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D006621:Hip Joint; D006801:Humans; D008954:Models, Biological; D016059:Range of Motion, Articular