Effect of dog breed and body conformation on vertical ground reaction forces, impulses, and stance times

Summary

Objectives: To assess whether fully normalised vertical ground reaction forces and stance times obtained at a trot depend on dog breed or body conformations.

Methods: Peak vertical forces (PVF), vertical impulses (VI), stance times (ST), and ratio of forelimb impulse to total impulse (R_VI) of 54 dogs of seven different breeds were normalised to body weight and body size according to the theory of dynamic similarity, and were tested for differences between breeds. Breeds were Borzoi, Bernese Mountain dog, Great Dane, Labrador Retriever, Landseer, Rhode-sian Ridgeback, and Rottweiler. Body length ratio (BLR) and body mass index (BMI) were also compared between breeds.

Results: Significant differences between breeds were found for the normalised fore-limb PVF, VI and ST, and hindlimb PVF. Looking at individual breeds, it was most evident that Borzois had a lower forelimb VI, and a higher hindlimb PVF than the other breeds. This resulted in Borzois having a lower R_VI compared to other dogs, indicating a more caudally located centre of gravity. Only a few differences in gait parameters were found between other dog breeds. The BMI was significantly lower in Borzois than in other breeds, but was otherwise not associated with gait parameters.

Clinical significance: Force plate data of dogs of different breeds are not necessarily comparable, even after full normalisation to body weight and body size. Group comparisons should only be made when the groups consist of breeds with similar body conformations.

Keywords

Force plate - data normalisation - breed - body conformation - impulse distribution

• References

• 1 Riggs CM, DeCamp CE, Soutas-Little RW. et al. Effects of subject velocity on force plate-measured ground reaction forces in healthy Greyhounds at a trot. Am J Vet Res 1993; 54: 1523-1526.
• 2 McLaughlin RM, Roush JK.. Effects of subject stance time and velocity on ground reaction forces in clinically normal Greyhounds at the trot. Am J Vet Res 1994; 55: 1666-1671.
• 3 Budsberg SC, Rytz U, Johnston SA. Effects of acceleration on ground reaction forces collected in healthy dogs at a trot. Vet Comp Orthop Traumatol 1999; 12: 15-19.
• 4 Rumph PF, Steiss JE, Montgomery RD. Effects of selection and habituation on vertical ground reaction force in Greyhounds. Am J Vet Res 1997; 58: 1206-1208.
• 5 Voss K, Imhof J, Kaestner S. et al. Comparison of clinical lameness scores of dogs with low-grade hindlimb lameness with force plate gait analysis at a walk and trot. Vet Comp Orthop Traumatol 2007; 20: 229-304.
• 6 Voss K, Galeandro L, Wiestner T. et al. Relationships of body weight, body size, subject velocity, and vertical ground reaction forces in trotting dogs. Vet Surg 2010; 39: 863-869.
• 7 Alexander R McN, Jayes AS. Dynamic similarity hypothesis for the gait of quadrupedal mammals. J Zool, London 1983; 201: 135-152.
• 8 Hof AL. Scaling gait data to body size. Gait Posture 1996; 4: 222-223.
• 9 Bertram JEA, Lee DV, Case HN. et al. Comparison of the trotting gaits of Labrador Retrievers and Greyhounds. Am J Vet Res 2000; 61: 832-838.
• 10 Lee DV, Bertram JEA, Todhunter RJ. Acceleration and balance in trotting dogs. J Exp Biol 1999; 202: 3565-3573.
• 11 Lee DV, Stakebake EF, Walter RM. et al. Effects of mass distribution on the mechanics of level trotting in dogs. J Exp Biol 2004; 207: 1715-1728.
• 12 Nunamaker DM, Blauner PD. Normal and abnormal gait. In: Newton CD, Nunamaker DM. editors Textbook of Small Animal Orthopaedics. Ithaca, New York: International Veterinary Information Services; 1985: 1-15.
• 13 Leach D. Locomotion analysis. In: Bojrab MJ. editor Disease Mechanisms in Small Animal Surgery. 2^nd edition. Philadelphia: WB Saunders; 1993: 1112-1118.
• 14 Williams SB, Wilson AM, Rhodes L. et al. Functional anatomy and muscle moment arms of the pelvic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris). J Anat 2008; 213: 361-372.