Relationship between Ground Reaction Forces and Morpho- Metric Measures in Two Different Canine Phenotypes Using Regression Analysis

SIMPLE SUMMARY: The force plate gait analysis is considered the gold standard for the objective assessment of limb function in dogs. Force plate analysis has been employed in several studies using a cohort of healthy dogs as a control group. However, these studies do not consider the subject variability within the same breed. Moreover, the lack of a rigorous analysis of morphometric variabilities in the same breed makes these evaluations poorly reliable. This prospective study aims to investigate the relationship between the ground reaction forces obtained by the force plate gait analysis and the morphometric measures in two different domestic dogs’ morphotypes. Our results highlighted how the ground reaction forces are influenced by morphometric measures not so much as a single contribution, but through the interaction between them. Indeed, the interaction between body weight, withers height, and velocity significantly influenced ground reaction forces with a greater unit increase for mesomorphs. Statistical models used in the available literature only partially explain the influence of morphometric measures on ground reaction forces, and the comparison between dogs should be made not referring to the breeds but the canine morphotype. ABSTRACT: Force plate analysis assesses gait symmetry and limb loading. However, as previously described, individual and breed variability (body size and conformation) is related to breeding, body conformation, and size. This prospective study aimed to evaluate the influence of morphometric measures on the speed (V), peak of vertical force (PVF), vertical impulse (VI), and stance time (ST) in healthy dolichomorph and mesomorph dogs and their combined effect on and interactions with V, PVF, VI, and ST in the same morphological types. Fifty dogs were enrolled in the current study, and specific morphometric measurements were recorded for each dog. A force platform was used to record the ground reaction forces (GFRs), including PVF and VI. Multiple linear regression models were used for the study purposes. According to our results, GFRs are influenced by morphometric measures (body weight, withers height, and speed) not so much as a single contribution, but by the interaction between them. It is not possible to compare GFRs in dogs that do not belong to the same breed. However, the subjective variabilities make this comparison difficult and poorly reliable. According to the author, the comparison should be made between canine morphological types rather than breeds.