title: Identifying optimal parameters for quantification of changes in pelvic movement symmetry as a response to diagnostic analgesia in the hindlimbs of horses.
abstract: BACKGROUND
  Subjective evaluation of the response to diagnostic analgesia of hindlimb lameness is influenced by expectation bias. Quantification of pelvic movement with inertial measurement units is possible, but it is unclear which measure of movement symmetry best reflects the changes seen after diagnostic analgesia.
  
  
  OBJECTIVE
  To test our hypothesis that objective measures closely relating to those used for subjective visual lameness scoring (quantifying the difference between sacral upward or downward movement or between movement amplitudes of the left and right tubera coxae) would show the largest and most consistent response.
  
  
  METHODS
  Retrospective analysis of subjective and objective clinical lameness data.
  
  
  METHODS
  Thirteen horses with hindlimb lameness underwent visual lameness scoring and independent gait assessment with inertial measurement units. Established objective measures were calculated and changes before/after diagnostic analgesia regressed against the change in lameness grade. Slopes of regression lines were calculated and confidence intervals assessed.
  
  
  RESULTS
  All objective parameters showed variation between horses and across lameness grades. The following 3 measures documented a consistent increase in symmetry for each grade of change in lameness score: difference between sacral displacement minima; upward movement difference; and range of motion difference between the tubera coxae.
  
  
  CONCLUSIONS
  Several pelvic parameters are suitable for objective quantification of changes after diagnostic analgesia in hindlimb-lame horses. A change of 9-13% per lameness grade can be expected. Upward movement of the tubera coxae is the most sensitive objective measure for quantifying a response to diagnostic analgesia. However, when assessed visually, this measure requires simultaneous focusing on pelvic and limb movements. Other parameters that show a similar response might be more easily perceived, requiring only assessment of tubera coxae range of motion or downward displacement of the sacrum without simultaneous focus on limb movement.
authors: Department of Clinical Science and Services, The Royal Veterinary College, University of London, Hatfield, UK.
authors: T
authors: T
authors: Pfau
authors: C
authors: C
authors: Spicer-Jenkins
authors: R K
authors: RK
authors: Smith
authors: D M
authors: DM
authors: Bolt
authors: A
authors: A
authors: Fiske-Jackson
authors: T H
authors: TH
authors: Witte
mesh_terms: D000698:Analgesia / Q000662:veterinary*; D000818:Animals; D001696:Biomechanical Phenomena; D006614:Hindlimb / Q000473:pathology*; D006734:Horse Diseases / Q000175:diagnosis*; D006736:Horses; D007794:Lameness, Animal / Q000175:diagnosis*; D008124:Locomotion; D018670:Monitoring, Ambulatory / Q000379:methods / Q000662:veterinary; D010388:Pelvis / Q000502:physiology*
keywords: diagnostic analgesia; hindlimb lameness; horse; movement symmetry; objective gait analysis