Fortbewegung und funktionelle Morphologie des Bewegungsapparates vom Zweifinger-Faultier (Choloepus didactylus)

该研究的总体目标是：1)有助于更好地理解树栖哺乳动物的运动运动学和动力学；2)更详细地了解重力对运动和相关肌肉骨骼适应的影响；3}对二趾和三趾树懒悬吊四足运动的趋同进化有更完整的进化理解。双翼高速x射线摄像使运动过程中近端肢体节段的三维运动可见。将悬吊式四足运动的运动学参数与树栖四足动物（来自我们自己实验室的数据）和臂举动物（文献）进行比较，将使我们能够更全面地理解这种特定的树栖运动模式。运动学数据还将用于逼真地动画ct扫描衍生的骨骼三维重建。在未来的项目中，像这样的动画重建将对推断化石形式的运动至关重要。肢体运动的运动学描述、肢体段质量分布的精确测量和基底反作用力的获得将有助于逆动力学分析（IDA）。IDA能够对树懒悬挂式四足运动时的加载状态和关节扭矩的几个假设进行实验验证。将描述两趾树懒参与运动的肌肉中的纤维类型组成和可能的功能区划，并将其与文献中描述的树栖和陆生哺乳动物肌肉结构的功能关系进行比较。这里概述的综合方法将阐明哺乳动物中树懒形态功能的不同方面，以便对其不寻常的运动行为的进化进行连贯的讨论。

The overarching goals of the proposed research are 1) a contribution to a better understanding of the kinematics and kinetics of locomotion in arboreal mammals in general, 2) a more detailed understanding of the influence of gravity on locomotion and linked musculoskeletal adaptations and 3} a more complete, evolutionary understanding of the convergent evolution of suspensory quadrupedal locomotion in two- and three-toed sloths.Biplane high-speed x-ray videography makes three-dimensional movements of proximal limb segments during locomotion visible. Comparisons of kinematic parameters of suspensory quadrupedal locomotion to both, arboreal quadrupeds (data from our own lab) and brachiators (literature) will enable a fuller comprehension of this specific mode of arboreal locomotion. Kinematic data will additionally be used to realistically animate CT-scan derived 3Dreconstructions of the skeleton. Animated reconstructions like these will be crucial for inferring locomotion in fossil forms in future projects.The kinematic description of limb movements, accurate measurements on mass distribution in the limb segments and substrate reaction forces obtained will facilitate inverse-dynamics analysis (IDA). IDA enables experimental validation of several hypotheses on the loading regime and joint torques during suspensory quadrupedal locomotion of sloths. Fibre-type composition and possible functional regionalisation within the muscles involved in locomotion of two-toed sloths will be described and compared to functional relationships of muscle-architecture described in the literature for arboreal and terrestrial mammals. The synthetic approach outlined here will illuminate different aspects of the morphofunction of sloths within mammals to enable a coherent discussion of the evolution of their unusual locomotor behaviour.