An examination of jump kinematics in dogs over increasing hurdle heights

Abstract

Research examining kinematic parameters of the canine athlete is markedly behind equivalent human and equine research. With increasing participation and popularity, canine sports science needs to bridge this gap with comparable equine research. The aim of this study was to examine changes to specific kinematic parameters as hurdle height increases. Twenty border collies and border collie crosses were analysed jumping over a single hurdle at increasing heights, starting with a pole on the floor and increasing to a maximum height of 65 cm. Length of trajectory and jump speed were analysed, alongside apparent (without the use of markers) neck, lumbar spine and shoulder angles using Dartfish software. For each dog, the percentage of the hurdle height in relation to their height at the dorsal aspect of the scapula (withers) was used to normalise the dogs evenly. Overall jump speed decreased as percentage height increased (P<0.001), with a strong negative correlation between the two (r=-0.815). Length of trajectory significantly increased with percentage height (P<0.001) with a strong positive correlation between the two (r=0.740). However, length of trajectory decreased when a dog jumped ≥126% of its height to the withers. This is supported by a significantly more flexed apparent neck angle upon landing at this percentage height (P<0.001). Apparent lumbar spine angles showed greater dorsal extension upon landing as percentage height increased (P<0.001). Apparent shoulder angles become significantly more flexed as percentage height increased during the suspension phase of the jump (P<0.001). These results suggest that dogs significantly alter their jump kinematics as hurdle height increases.