School of Science and Engineering, University of the Sunshine Coast, Sippy Downs, QLD 4558, Australia.
Kristiansand Dyrepark, 4609 Kardemomme by, Norway.
J Exp Biol. 2022 Nov 1;225(21). doi: 10.1242/jeb.244435. Epub 2022 Nov 14.
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 with smaller and larger bodied dogs. Body shape also had a complex pattern, with longer forelimbs but shorter hindlimbs being associated with better turning ability. Further, although 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 with 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.
机动性，即快速改变方向的能力，是动物运动的核心。转弯性能可能取决于成功完成关键挑战的能力，包括：承受额外的侧向力、保持足够的摩擦力、转弯过程中的侧向倾斜以及旋转身体以与新的行进方向对齐。我们拍摄了家养犬（Canis lupus familiaris）的高速转弯，以量化转弯性能并探索性能如何随体型和形状的变化而变化。最大速度随角速度的增加、向心加速度的增加和转弯半径的减小而降低，这支持了较宽转弯的力限制和较急转弯的摩擦限制。转弯能力随尺寸的变化很复杂：中型犬产生更大的向心力，相对较高的摩擦系数，并且通常与较小和较大体型的犬相比，身体与行进方向更好地对齐。身体形状也有复杂的模式，前肢较长，但后肢较短，与更好的转弯能力相关。此外，尽管更蜷缩的前肢与增加身体在运动方向上重新对齐的能力有关，但更直立的后肢与更大的向心加速度和切向加速度有关。因此，我们证明这些转弯的生物力学挑战不仅会随着速度或转弯半径的变化而变化，还会随着形态的变化而变化。这些结果将对理解运动研究中形态与功能之间的联系具有重要意义，但也对预测捕食者-猎物相遇的结果具有重要意义。
