SUMMARY
Objective
To determine effect of dog selection and habituation on vertical ground reaction force variables.
Animals
133 Greyhounds of either sex, weighing between 22 and 39 kg.
Procedure
Vertical ground reaction force variables (peak [PFz] and impulse [IFz]) for hind limbs were studied in dogs at 3 levels of habituation. Dogs of group 1 (n = 81) did not have prior experience with the gait analysis routine. Group-2 dogs (n = 52) were selected for having an amiable disposition, and were first evaluated after participating in an intermediate habituation routine (group 2a). These dogs were reevaluated after undergoing the full habituation routine (group 2b).
Results
3 of the ground reaction force variables differed significantly between dogs of groups 1 and 2 (a and b). Dogs that had not been habituated to the gait analysis routine (group 1) had significantly longer stance times than did dogs that had been more carefully selected and habituated. Intradog coefficients of variation for PFz and the IFz were significantly greater in group-1 dogs. The PFz for group-2a dogs was significantly greater than that for group-1 dogs. Differences identified between groups 2a and 2b were more likely to be attributed to habituation only. These included significantly shorter stance time and lower intradog coefficient of variation for IFz in dogs having the highest level of habituation.
Conclusion
Selection and habituation have measurable effects on vertical ground reaction force data obtained from trotting dogs. These include significantly shorter hind limb stance times, lower impulses of vertical force, with smaller coefficients of variation for peaks and impulses of vertical force within dogs.
Clinical Relevance
In controlled studies where critical decision making is based on gait analysis data, careful selection of subjects and habituation will significantly improve precision of the data and has the potential to reduce the subject or repetition sample size. (Am J Vet Res 1997;58:1206–1208)
