title: Changes in kinematic variables observed during pressure-induced forelimb lameness in adult horses trotting on a treadmill.
abstract: OBJECTIVE
  To determine whether kinematic changes induced by heel pressure in horses differ from those induced by toe pressure.
  
  
  METHODS
  10 adult Quarter Horses.
  
  
  METHODS
  A shoe that applied pressure on the cuneus ungulae (frog) or on the toe was used. Kinematic analyses were performed before and after 2 levels of frog pressure and after 1 level of toe pressure. Values for stride displacement and time and joint angles were determined from horses trotting on a treadmill.
  
  
  RESULTS
  The first level of frog pressure caused decreases in metacarpophalangeal (fetlock) joint extension during stance and increases in head vertical movement and asymmetry. The second level of frog pressure caused these changes but also caused decreases in stride duration and carpal joint extension during stance as well as increases in relative stance duration. Toe pressure caused changes in these same variables but also caused maximum extension of the fetlock joint to occur before midstance, maximum hoof height to be closer to midswing, and forelimb protraction to increase.
  
  
  CONCLUSIONS
  Decreased fetlock joint extension during stance and increased head vertical movement and asymmetry are sensitive indicators of forelimb lameness. Decreased stride duration, increased relative stance duration, and decreased carpal joint extension during stance are general but insensitive indicators of forelimb lameness. Increased forelimb protraction, hoof flight pattern with maximum hoof height near midswing, and maximum fetlock joint extension in cranial stance may be specific indicators of lameness in the toe region. Observation of forelimb movement may enable clinicians to differentiate lameness of the heel from lameness of the toe.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
authors.forename: K G
authors.initials: KG
authors.lastname: Keegan
authors.forename: D A
authors.initials: DA
authors.lastname: Wilson
authors.forename: B K
authors.initials: BK
authors.lastname: Smith
authors.forename: D J
authors.initials: DJ
authors.lastname: Wilson
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D005080:Exercise Test / Q000662:veterinary; D005260:Female; D005552:Forelimb / Q000503:physiopathology*; D005684:Gait / Q000502:physiology; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D007091:Image Processing, Computer-Assisted; D007794:Lameness, Animal / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology; D011312:Pressure; D018709:Statistics, Nonparametric; D016474:Weight-Bearing