Bryan T. Torres1, DVM, John P. Punke1, DVM, Yang-Chieh Fu2, MS, Judith A. Navik3, BS, Abbie L. Speas1, BS, Andrew Sornborger4, PhD, and Steven C. Budsberg1, DVM, MS, Diplomate ACVS
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA,2Department of Kinesiology, College of Education, University of Georgia, Athens, GA, 3Department of Biological and Agricultural Engineering, College of Agricultural and Environmental Sciences, University of Georgia, Athens, GA and 4Department of Mathematics, Faculty of Engineering, University of Georgia, Athens, GA
Corresponding Author Dr. Budsberg, Department of Small Animal Medicine and Surgery,University of Georgia, Athens, GA 30602 E-mail: firstname.lastname@example.org Submitted May 2009 Accepted September 2009 DOI:10.1111/j.1532-950X.2010.00666.x
Objective: To model the kinematics of the canine stiﬂe in 3 dimensions using the Joint Coordinate System (JCS) and compare the JCS method with linear and segmental models. Study Design: In vivo biomechanical study. Animals: Normal adult mixed breeddogs (n = 6). Methods: Dogs had 10 retroreﬂective markers afﬁxed to the skin on the right pelvic limb. Dogs were walked and trotted 5 times through the calibrated space and the procedure was repeated 5 days later. Sagittal ﬂexion and extension angle waveforms acquired during each trial with all 3 models (JCS, Linear, and Segmental) were produced simultaneously during each gait. The JCS methodprovided additional internal/external and abduction/adduction angles. Comparison of sagittal ﬂexion and extension angle waveforms was performed with generalized indicator function analysis (GIFA) and Fourier analysis. A normalization procedure was performed. Results: Each model provided consistent equivalent sagittal ﬂexion–extension data. The JCS provided consistent additional internal/external andabduction/adduction. Sagittal waveform differences were found between methods and testing days for each dog at a walk and a trot with both GIFA and Fourier analysis. After normalization, differences were less with Fourier analysis and were unaltered with GIFA. Conclusions: Whereas all methods produced similar ﬂexion–extension waveforms, JCS provided additional valuable data. Clinical Relevance: TheJCS model provided sagittal plane ﬂexion/extension data as well as internal/external rotation and abduction/adduction data. relevant 3-D description of joint motion with 6 degrees of freedom. Whereas analysis of kinematic gait data in veterinary medicine has often focused on associated gait waveforms, analysis methodology has varied. Gait waveforms have been analyzed with polynomial equations6,8;Fourier analysis4,5,7,9; and principal component analysis.10 Another methodology that may prove useful in the evaluation of canine gait waveforms is generalized indicator function analysis (GIFA).11 This is a multivariate vector waveform analysis method that maximizes signal power while maintaining a large signal-to-noise ratio, and provides the ability to assess differences at speciﬁc points alongthe waveforms. Our purpose was to model 3-D kinematics of the canine stiﬂe with the JCS,12 and compare the JCS method with more traditional sagittal plane models of the canine stiﬂe. Our hypothesis was that the JCS model would provide sagittal plane ﬂexion/extension femorotibial angles
Clinical kinematic studies have been under used in veterinary medicine.1 Previously, studies have focused onjoint motion with respect to ﬂexion and extension; however, joint movement is complex and incompletely represented in a 2-dimensional (2-D) model.2 Interestingly, recent evidence has indicated that kinematic evaluation may be more sensitive than force platform, or kinetic, evaluation for detection of subclinical orthopedic disease.3 Historically, linear-link models of the canine hindlimb have...