title: Two-dimensional link-segment model of the forelimb of dogs at a walk.
abstract: OBJECTIVE
  To calculate normative joint angle, intersegmental forces, moment of force, and mechanical power at elbow, antebrachiocarpal, and metacarpophalangeal joints of dogs at a walk.
  
  
  METHODS
  6 clinically normal mixed-breed dogs.
  
  
  METHODS
  Kinetic data were collected via a force platform, and kinematic data were collected from forelimbs by use of 3-dimensional videography. Length, location of the center of mass, total mass, and mass moment of inertia about the center of mass were determined for each of 4 segments of the forelimb. Kinematic data and inertial properties were combined with vertical and craniocaudal ground reaction forces to calculate sagittal plane forces and moments across joints of interest throughout stance phase. Mechanical power was calculated as the product of net joint moment and the angular velocity. Joint angles were calculated directly from kinematic data.
  
  
  RESULTS
  All joint intersegmental forces were similar to ground reaction forces, with a decrease in magnitude the more proximal the location of each joint. Flexor moments were observed at metacarpophalangeal and antebrachiocarpal joints, and extensor moments were observed at elbow and shoulder joints, which provided a net extensor support moment for the forelimb. Typical profiles of work existed for each joint.
  
  
  CONCLUSIONS
  For clinically normal dogs of a similar size at a walk, inverse dynamic calculation of intersegmental forces, moments of force, and mechanical power for forelimb joints yielded values of consistent patterns and magnitudes. These values may be used for comparison in evaluations of gait in other studies and in treatment of dogs with forelimb musculoskeletal disease.
authors.affiliation: J.D. Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: Cheri
authors.initials: C
authors.lastname: Nielsen
authors.forename: Susan M
authors.initials: SM
authors.lastname: Stover
authors.forename: Kurt S
authors.initials: KS
authors.lastname: Schulz
authors.forename: Mont
authors.initials: M
authors.lastname: Hubbard
authors.forename: David A
authors.initials: DA
authors.lastname: Hawkins
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs / Q000502:physiology*; D005260:Female; D005552:Forelimb / Q000033:anatomy & histology* / Q000502:physiology*; D005684:Gait / Q000502:physiology; D007596:Joints / Q000502:physiology; D008297:Male; D005082:Physical Exertion / Q000502:physiology; D012016:Reference Values; D016138:Walking / Q000502:physiology*