Relationships of body weight, body size, subject velocity, and vertical ground reaction forces in trotting dogs.
OBJECTIVE
To evaluate the relationship of body weight (BW) and size, dog velocity, and vertical ground reaction forces (GRF) from a large number of dogs of various sizes.


METHODS
Clinical research.


METHODS
Orthopedically healthy dogs (n=129)


METHODS
BW and dog size, represented as height at the withers (WH), were obtained. Stance times (ST), vertical impulses (VI), and peak vertical forces (PVF) of thoracic and pelvic limbs were measured on a force plate at controlled trotting speed. They were evaluated against BW and WH using linear regression analysis in absolute (nonnormalized) values, and when normalized to BW and/or body size according to the theory of dynamic similarity. Relative velocities were calculated for each dog.


RESULTS
Absolute ST, VI, and PVF showed strong positive correlations with BW and/or body size. When GRFs were normalized to BW, correlations with body size were markedly reduced, but remained positive for VI, and turned negative for PVF. Normalizing the time-dependent variables (ST and VI) also to WH eliminated most size influence. A small dependency of fully normalized GRF on body size remained that was because of differences in relative velocity between dogs of different sizes. Reference values for the fully normalized data are given.


CONCLUSIONS
The inherent relationship between BW, body size, dog velocity, and vertical GRF was demonstrated.


CONCLUSIONS
BW, body size, and relative dog velocity must be accounted for when wanting to obtain GRF variables that are comparable between different dogs.
Voss
Katja
K
Small Animal Clinic, Vetsuisse Faculty University of Zurich, Zurich, Switzerland. katja.voss@sydney.edu.au
Galeandro
Luca
L
Wiestner
Thomas
T
Haessig
Michael
M
Montavon
Pierre M
PM
D000818:Animals; D049628:Body Size / Q000502:physiology*; D001835:Body Weight / Q000502:physiology*; D004285:Dogs / Q000502:physiology*; D005552:Forelimb; D005684:Gait / Q000502:physiology*; D006614:Hindlimb; D009043:Motor Activity; D012420:Running / Q000502:physiology*