TY - JOUR
T1 - A new method for estimating joint parameters from motion data
AU - Schwartz, Michael H.
AU - Rozumalski, Adam
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/1
Y1 - 2005/1
N2 - Joint centers and axes of rotation (joint parameters) are central to all branches of movement analysis. In gait analysis, the standard protocol used to determine hip and knee joint parameters is prone to errors arising from palpation, anthropometric regression equations, and misplaced alignment devices. Several alternative methods have been proposed, but to date none have been shown to be accurate and reliable enough for use in the clinical setting. This article describes a new method for joint parameter estimation. The new method can be summarized as follows: (i) the motions of two adjacent segments spanning a single joint are tracked, (ii) the axis of rotation between every pair of observed segment configurations is computed, (iii) the most likely intersection of all axes (effective joint center) and most likely orientation of the axes (effective joint axis) is found. Initial validation of the method was conducted on a hinged mechanical analog and a single healthy adult subject. For the analog, the center was found to be within 3.8mm of the geometric center and 2.0° of the geometric axis (standard deviation). For the adult subject, hip centers varied on the order of 1-3mm, knee centers by 3-9mm, and knee axes by 2.0°. The results suggest that the new method is an objective, precise, and practical alternative to the standard clinical approach.
AB - Joint centers and axes of rotation (joint parameters) are central to all branches of movement analysis. In gait analysis, the standard protocol used to determine hip and knee joint parameters is prone to errors arising from palpation, anthropometric regression equations, and misplaced alignment devices. Several alternative methods have been proposed, but to date none have been shown to be accurate and reliable enough for use in the clinical setting. This article describes a new method for joint parameter estimation. The new method can be summarized as follows: (i) the motions of two adjacent segments spanning a single joint are tracked, (ii) the axis of rotation between every pair of observed segment configurations is computed, (iii) the most likely intersection of all axes (effective joint center) and most likely orientation of the axes (effective joint axis) is found. Initial validation of the method was conducted on a hinged mechanical analog and a single healthy adult subject. For the analog, the center was found to be within 3.8mm of the geometric center and 2.0° of the geometric axis (standard deviation). For the adult subject, hip centers varied on the order of 1-3mm, knee centers by 3-9mm, and knee axes by 2.0°. The results suggest that the new method is an objective, precise, and practical alternative to the standard clinical approach.
KW - Axis of rotation
KW - Center of rotation
KW - Gait analysis
KW - Joint center
KW - Precision
UR - http://www.scopus.com/inward/record.url?scp=7044250698&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=7044250698&partnerID=8YFLogxK
U2 - 10.1016/j.jbiomech.2004.03.009
DO - 10.1016/j.jbiomech.2004.03.009
M3 - Article
C2 - 15519345
AN - SCOPUS:7044250698
SN - 0021-9290
VL - 38
SP - 107
EP - 116
JO - Journal of Biomechanics
JF - Journal of Biomechanics
IS - 1
ER -