Exploring the limits to turning performance with size and shape variation in dogs

Abstract

Manoeuvrability, the ability to make rapid changes in direction, is central to animal locomotion. Turning performance may depend on the ability to successfully complete key challenges including; Withstanding additional lateral forces, Maintaining sufficient friction, Lateral leaning during a turn, and Rotating the body to align with the new heading. We filmed high-speed turning in domestic dogs (Canis lupus familiaris) to quantify turning performance and explore how performance varies with body size and shape. Maximal speed decreased with higher angular velocity, greater centripetal acceleration, and smaller turning radii supporting a force limit for wider turns and a friction limit for sharp turns. Variation in turning ability with size was complex, medium sized dogs produced greater centripetal forces, had relatively higher friction coefficients, and generally aligned the body better with the heading compared to smaller and larger bodied dogs. Body shape further had complex pattern, with longer forelimbs but shorter hindlimbs being associated with better turning ability. Further, while more crouched forelimbs were associated with an increased ability to realign the body in the direction of movement, more upright hindlimbs were related to greater centripetal and tangential accelerations. Thus, we demonstrate that these biomechanical challenges to turning can vary not only with changes in speed or turning radius, but also changes in morphology. These results will have significant implications for understanding the link between form and function in locomotory studies, but also in predicting the outcome of predator prey encounters.

The air conditioning in the nose of mammals depends on their mass and on their maximal running speed

“…Maximal running speeds for the cat, horse, rabbit, and adult human come directly from Garland et al 34 . We define the maximal running speed of the dog as the average maximal speed of 7–8 kg dogs in the study of Haagensen et al 37 . To determine the maximal running speed of an 11-years-old girl, we multiply her average running speed 38 by the ratio between the maximal 34 and the average 38 running speeds for male adults.…”

How scaling approaches can reveal fundamental principles in physiology and biomechanics

“…Current scaling analysis in terrestrial animals has focused on the well-studied and most common forms of steady-state locomotion; for example walking, running and hopping. It would be exciting to apply scaling principles to understand locomotor performance during non-steady movements; for example, while navigating uneven terrain (Birn-Jeffery et al, 2014) or during turning manoeuvres (Haagensen et al, 2022). These are perhaps more relevant to the diversity of behaviours that animals perform in their natural environments.…”

Biomechanical modeling of Border Collies (Canis familiaris) for insights of tail and limb use during the aerial phase of jumping

“…Controlling the body’s posture is important in allowing animals to locomote through complex environments (Huang and Ahmed, 2011; Wilshin, Reeve and Spence, 2021; Biewener et al ., 2022). For example, in enabling effective acceleration (Walter and Carrier, 2009; Hayati et al ., 2017), agile maneuvering (Powers and Harrison, 1999; Söhnel et al ., 2020), and turning (Powers and Harrison, 1999; Foreman, Engsberg and Foreman, 2019; Shield et al ., 2021; Söhnel et al ., 2021; Haagensen et al ., 2022). In these studies, animals move in specific ways, and then analytical models are utilized to inform the changes in their body’s locomotive patterns and behavior.…”