The head contains the visual and the vestibular receptor organs, both of which are important for the control of locomotion. When animals make a turn, they inevitably lean into the circle, or rotate in roll. The aim of this study was to quantify roll rotation of the head and trunk in agility dogs to test the hypothesis that dogs maintain stability of the head in roll independently from the trunk during high-speed turning. Five agility dogs were required to run on a figure-of-eight course. Inertial measurement units (IMUs) comprising gyroscopes and accelerometers were attached to three locations along the body midline: the head, withers (upper trunk), and tuber sacrale (lower trunk). Roll rotation of body segments was estimated using a Madgwick filter. All the body segments leant more to the right during clockwise turning and more to the left during counterclockwise turning. The roll amplitude of the head was approximately half those of the withers and tuber sacrale. These findings support our hypothesis and suggest that head stabilization in roll leads to better vision and vestibular perception during high-speed turning than if roll orientation of the head is fixed to the trunk.

Published online 13 March, 2024; Print publication 30 April, 2024