title: Kinematics and ground reaction forces in horses with superficial digital flexor tendinitis.
abstract: OBJECTIVE
  To measure and correlate kinematic and ground reaction force (GRF) data in horses with superficial digital flexor tendinitis.
  
  
  METHODS
  6 sound horses.
  
  
  METHODS
  Horses were evaluated before (sound evaluation) and after (lame evaluation) induction of superficial digital flexor tendinitis in 1 forelimb (randomized) by injection of collagenase. As each horse trotted, kinematic data were collected by use of an optoelectronic system, and GRF data were measured by use of a force plate. Three-dimensional kinematic and GRF data were projected onto a 2-dimensional sagittal plane.
  
  
  RESULTS
  Lame limbs had significantly lower peak vertical GRF, less flexion of the distal interphalangeal joint, and less extension of the metacarpophalangeal joint, compared with compensating limbs. Carpal joint kinematics did not change. Compensating limbs had a more protracted orientation throughout the stance phase and higher braking longitudinal force and impulse; however, total range of rotation from ground contact to lift off did not change. Transfer of body weight from lame to compensating limbs was smooth, without elevation of the body mass into a suspension phase. Propulsive components of longitudinal GRF did not differ between limbs.
  
  
  CONCLUSIONS
  In horses with experimentally induced superficial digital flexor tendinitis, changes in vertical GRF were reflected in angular excursions of the distal interphalangeal and metacarpophalangeal joints, whereas changes in longitudinal GRF were associated with alterations in the protraction-retraction angle of the entire limb.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing 48824-1314, USA.
authors.forename: H M
authors.initials: HM
authors.lastname: Clayton
authors.forename: H C
authors.initials: HC
authors.lastname: Schamhardt
authors.forename: M A
authors.initials: MA
authors.lastname: Willemen
authors.forename: J L
authors.initials: JL
authors.lastname: Lanovaz
authors.forename: G R
authors.initials: GR
authors.lastname: Colborne
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses; D007091:Image Processing, Computer-Assisted; D007596:Joints / Q000503:physiopathology; D007794:Lameness, Animal / Q000503:physiopathology*; D009068:Movement; D011187:Posture; D052256:Tendinopathy / Q000503:physiopathology / Q000662:veterinary*; D013710:Tendons / Q000503:physiopathology*