Panagiotopoulou Olga, Pataky Todd C, Hutchinson John R
Monash Biomedicine Discovery Institute, Department of Anatomy and Developmental Biology, Moving Morphology & Functional Mechanics Laboratory, Monash University, Clayton, VIC, Australia.
Department of Human Health Sciences, Kyoto University, Kyoto, Japan.
PeerJ. 2019 May 15;7:e6881. doi: 10.7717/peerj.6881. eCollection 2019.
White rhinoceroses () are odd-toed ungulates that belong to the group Perissodactyla. Being second only to elephants in terms of large body mass amongst extant tetrapods, rhinoceroses make fascinating subjects for the study of how large land animals support and move themselves. Rhinoceroses often are kept in captivity for protection from ivory poachers and for educational/touristic purposes, yet a detrimental side effect of captivity can be foot disease (i.e., enthesopathies and osteoarthritis around the phalanges). Foot diseases in large mammals are multifactorial, but locomotor biomechanics (e.g., pressures routinely experienced by the feet) surely can be a contributing factor. However, due to a lack of in vivo experimental data on rhinoceros foot pressures, our knowledge of locomotor performance and its links to foot disease is limited. The overall aim of this study was to characterize peak pressures and center of pressure trajectories in white rhinoceroses during walking. We asked two major questions. First, are peak locomotor pressures the lowest around the fat pad and its lobes (as in the case of elephants)? Second, are peak locomotor pressures concentrated around the areas with the highest reported incidence of pathologies? Our results show a reduction of pressures around the fat pad and its lobes, which is potentially due to the material properties of the fat pad or a tendency to avoid or limit "heel" contact at impact. We also found an even and gradual concentration of foot pressures across all digits, which may be a by-product of the more horizontal foot roll-off during the stance phase. While our exploratory, descriptive sample precluded hypothesis testing, our study provides important new data on rhinoceros locomotion for future studies to build on, and thus impetus for improved implementation in the care of captive/managed rhinoceroses.
白犀牛属于奇蹄目有蹄类动物。在现存的四足动物中，白犀牛的体重仅次于大象，是研究大型陆地动物如何支撑身体和移动的有趣研究对象。犀牛常被圈养起来，以保护它们免受象牙偷猎者的伤害，并用于教育/旅游目的，但圈养的一个不利副作用可能是足部疾病（即趾骨周围的附着点病和骨关节炎）。大型哺乳动物的足部疾病是多因素的，但运动生物力学（例如，足部经常承受的压力）肯定是一个促成因素。然而，由于缺乏关于犀牛足部压力的体内实验数据，我们对其运动表现及其与足部疾病的联系的了解有限。本研究的总体目标是描述白犀牛行走过程中的峰值压力和压力中心轨迹。我们提出了两个主要问题。第一，运动峰值压力在脂肪垫及其叶周围是否是最低的（就像大象的情况一样）？第二，运动峰值压力是否集中在报告的病理发生率最高的区域周围？我们的结果表明，脂肪垫及其叶周围的压力降低，这可能是由于脂肪垫的材料特性，或者是在撞击时避免或限制“脚跟”接触的倾向。我们还发现，所有趾上的足部压力均匀且逐渐集中，这可能是站立阶段足部更水平滚落的副产品。虽然我们的探索性描述性样本无法进行假设检验，但我们的研究为未来的研究提供了关于犀牛运动的重要新数据，从而为改善圈养/管理犀牛的护理措施提供了动力。
