title: Comparison of two-dimensional and three-dimensional systems for kinematic analysis of the sagittal motion of canine hind limbs during walking.
abstract: OBJECTIVE
  To test the hypotheses that kinematic data of the sagittal motion of canine hind limbs during walking obtained with a 2-dimensional (2-D) system correlate well with those obtained with a 3-dimensional (3-D) system and that the data obtained with the 2-D system are repeatable.
  
  
  METHODS
  6 adult dogs with no evidence of lameness.
  
  
  METHODS
  Hind limb motions of 6 walking dogs were recorded via 2-D video and 3-D optoelectric systems simultaneously. Five valid trials were digitized, and 5 data sets (2-D 60 Hz, 3-D 180 Hz, 3-D sagittal 180 Hz, 3-D 60 Hz, and 3-D sagittal 60 Hz) of a complete gait cycle were created for each dog. In sagittal data sets, 3-D data were reduced to exclude coordinates for mediolateral orientation. Temporospatial parameters; angles of hip, stifle, and tarsal joints; and coefficients of variation of angular measurements of each dog were calculated for each data set. Accuracy of the 2-D analysis was determined by calculating mean absolute differences and estimating agreement between the 2-D and 3-D 180-Hz data sets.
  
  
  RESULTS
  Values of joint angles and angular excursions measured with the 2-D system were repeatable and agreed with respective values obtained with the 3-D system. Reduction of the sampling rate had a greater impact on values of kinematic variables obtained with the 3-D system than did elimination of data on mediolateral orientation.
  
  
  CONCLUSIONS
  Kinematic analysis using a 2-D video system provided accurate and repeatable data of the sagittal angular motion of canine hind limbs during walking.
authors.affiliation: Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Jongmin
authors.initials: J
authors.lastname: Kim
authors.forename: Shirley
authors.initials: S
authors.lastname: Rietdyk
authors.forename: Gert J
authors.initials: GJ
authors.lastname: Breur