title: Changes in frontal plane dynamics and the loading response phase of the gait cycle are characteristic of severe knee osteoarthritis application of a multidimensional analysis technique.
abstract: BACKGROUND
  Osteoarthritis of the knee is related to many correlated mechanical factors that can be measured with gait analysis. Gait analysis results in large data sets. The analysis of these data is difficult due to the correlated, multidimensional nature of the measures.
  
  
  METHODS
  A multidimensional model that uses two multivariate statistical techniques, principal component analysis and discriminant analysis, was used to discriminate between the gait patterns of the normal subject group and the osteoarthritis subject group. Nine time varying gait measures and eight discrete measures were included in the analysis. All interrelationships between and within the measures were retained in the analysis.
  
  
  RESULTS
  The multidimensional analysis technique successfully separated the gait patterns of normal and knee osteoarthritis subjects with a misclassification error rate of <6%. The most discriminatory feature described a static and dynamic alignment factor. The second most discriminatory feature described a gait pattern change during the loading response phase of the gait cycle.
  
  
  CONCLUSIONS
  The interrelationships between gait measures and between the time instants of the gait cycle can provide insight into the mechanical mechanisms of pathologies such as knee osteoarthritis. These results suggest that changes in frontal plane loading and alignment and the loading response phase of the gait cycle are characteristic of severe knee osteoarthritis gait patterns. Subsequent investigations earlier in the disease process may suggest the importance of these factors to the progression of knee osteoarthritis.
authors.affiliation: School of Biomedical Engineering, Dalhousie University, 5981 University Avenue, Halifax, NS, Canada B3H 3J5.
authors.forename: J L
authors.initials: JL
authors.lastname: Astephen
authors.forename: K J
authors.initials: KJ
authors.lastname: Deluzio
mesh_terms: D000222:Adaptation, Physiological; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D016002:Discriminant Analysis; D005260:Female; D005684:Gait; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007866:Leg / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015233:Models, Statistical; D015999:Multivariate Analysis; D017711:Nonlinear Dynamics; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000503:physiopathology*; D016474:Weight-Bearing