title: Validation of a laboratory method for evaluating dynamic properties of reconstructed equine racetrack surfaces.
abstract: BACKGROUND
  Racetrack surface is a risk factor for racehorse injuries and fatalities. Current research indicates that race surface mechanical properties may be influenced by material composition, moisture content, temperature, and maintenance. Race surface mechanical testing in a controlled laboratory setting would allow for objective evaluation of dynamic properties of surface and factors that affect surface behavior.
  
  
  OBJECTIVE
  To develop a method for reconstruction of race surfaces in the laboratory and validate the method by comparison with racetrack measurements of dynamic surface properties.
  
  
  METHODS
  Track-testing device (TTD) impact tests were conducted to simulate equine hoof impact on dirt and synthetic race surfaces; tests were performed both in situ (racetrack) and using laboratory reconstructions of harvested surface materials. Clegg Hammer in situ measurements were used to guide surface reconstruction in the laboratory. Dynamic surface properties were compared between in situ and laboratory settings. Relationships between racetrack TTD and Clegg Hammer measurements were analyzed using stepwise multiple linear regression.
  
  
  RESULTS
  Most dynamic surface property setting differences (racetrack-laboratory) were small relative to surface material type differences (dirt-synthetic). Clegg Hammer measurements were more strongly correlated with TTD measurements on the synthetic surface than the dirt surface. On the dirt surface, Clegg Hammer decelerations were negatively correlated with TTD forces.
  
  
  CONCLUSIONS
  Laboratory reconstruction of racetrack surfaces guided by Clegg Hammer measurements yielded TTD impact measurements similar to in situ values. The negative correlation between TTD and Clegg Hammer measurements confirms the importance of instrument mass when drawing conclusions from testing results. Lighter impact devices may be less appropriate for assessing dynamic surface properties compared to testing equipment designed to simulate hoof impact (TTD).
  
  
  CONCLUSIONS
  Dynamic impact properties of race surfaces can be evaluated in a laboratory setting, allowing for further study of factors affecting surface behavior under controlled conditions.
authors.affiliation: Biomedical Engineering Graduate Group, University of California Davis, Davis, California, United States of America.
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Setterbo
authors.forename: Anh
authors.initials: A
authors.lastname: Chau
authors.forename: Patricia B
authors.initials: PB
authors.lastname: Fyhrie
authors.forename: Mont
authors.initials: M
authors.lastname: Hubbard
authors.forename: Shrini K
authors.initials: SK
authors.lastname: Upadhyaya
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Symons
authors.forename: Susan M
authors.initials: SM
authors.lastname: Stover
mesh_terms: D000818:Animals; D006736:Horses; D012420:Running / Q000293:injuries; D013499:Surface Properties