Does Form Define Function? Relationships Between Body Conformation and Dynamic Locomotor Patterns in Quarter Horses

• Grant number: 25/11472-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry
• Principal Investigator: Renata Farinelli de Siqueira
• Grantee: Lavinia Andressa Brito
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Associated research grant: 24/13083-6 - Objective Analysis of the Locomotion of Hippotherapy Horses: Integration of Morphometric and Sensor Data, AP.R

Abstract

Equine locomotion results from the interaction of morphological characteristics and specific biomechanical demands, particularly in athletic horses. In the Quarter Horse breed, known for disciplines such as reining, cutting, ranch sorting, and barrel racing, it is hypothesized that factors like joint angles, body proportions, and segmental widths directly correlate with athletic performance. However, the literature lacks biomechanical models that objectively integrate morphometric variables with dynamic locomotion parameters, which limits progress in functional selection and injury prevention. This project aims to examine the relationship between body conformation and biomechanical locomotion parameters in Quarter Horses, comparing various sport disciplines with a control group. Seventy-five horses will be evaluated, divided into five groups (n=15) according to discipline: reining, cutting, ranch sorting, barrel racing, and control (young, broke horses without specific athletic training). Morphometric analysis will include linear, proportional, and angular measurements obtained through digital photogrammetry using ImageJ® software. Locomotion assessment will utilize EquiMoves® inertial sensor technology to quantify stride parameters such as protraction, retraction, adduction, abduction, vertical displacement, and locomotor symmetry. Data will be analyzed using multivariate statistical methods, including Principal Component Analysis (PCA) to identify morpho-functional axes and reduce dimensionality. Linear mixed models and discriminant analysis will be employed to investigate the associations between morphological variables and the biomechanical patterns characteristic of each group. This study will provide novel insights into the relationship between form and locomotor function in the Quarter Horse breed, contributing to functional selection, optimization of training protocols, and injury prevention, with a direct impact on the national equine sports industry. (AU)