Experimental determination of the impact of ambient temperatures on leg coordination, force distribution and body dynamics of fast locomotion in arthropods and 3D numerical modelling of polypedal locomotion.

节肢动物由于其丰富、实用的普遍性以及其形态、行为和生态多样性，是最重要的生态行为者之一。然而，令人惊讶的是，人们对它们的陆地运动知之甚少，特别是在更高的跑步速度上。大多数现有的研究都集中在少数几个实验室物种上，这些物种很难涵盖节肢动物身体结构的巨大多样性。节肢动物的身体有许多不同的参数。关于运动生理学，重要的参数是推进腿的数量、身体大小、姿势和动力学、腿的设计和长度、计时和协调以及腿力产生和转移到地面的方式。力量的产生取决于腿部肌肉功能及其局限性。这些参数中的许多都受到环境温度的限制，也就是说，到目前为止，在移动的背景下，几乎没有人研究过这种限制。在以前的实验中，我能够证明温度对蟑螂所有可能的运动学参数的巨大影响。然而，需要一个关于节肢动物运动的更大的数据库。因此，我计划研究生态适应性不同的节肢动物的运动，比如跑得快和跑得慢的节肢动物，具有不同数量推进腿的节肢动物，如昆虫和蜘蛛类动物，以及不同身体尺寸的节肢动物，如半代谢物种的幼体和成体。3D运动学应分别在三种不同的温度下进行检查。腿传递到地面的力以及这些力之间的相互作用决定了运动的动力学、稳定性和能量学。我计划检查地面反作用力，特别是在高速运行时，以揭示腿部之间的相互作用和许多腿部设计的被动贡献，如弹性和阻尼。为了完成这幅图，将使用组织学方法绘制腿部驱动的属性，即肌肉，以确定肌球蛋白-ATPase活性和肌节长度，这提供了有关收缩速度和最大肌肉应力的信息。对于关键物种，将直接研究具有重要功能的腿部肌肉的收缩特性，如力-长度关系和力-速度关系。节肢动物运动的运动学、动力学和地面反作用力以及肌肉收缩特性的数据将用于开发多通道可伸缩的3D模型。这一多方面的方法结合了对快速节肢动物物种运动动力学的研究，涵盖了一系列运动装置和温度状态，检查了肌肉特性，并开发了改进的数值模型，具有进一步整合形态和功能知识、连接功能和生态的高潜力，并可能导致知识转移到技术实施中。

Owing to their abundance, practical ubiquity as well as their morphological, behavioural and ecological diversity, arthropods are among the most important ecological actors. However, surprisingly little is known about their terrestrial locomotion, particularly on higher running speeds. Most available studies focus on a few laboratory species, which hardly cover the immense diversity of arthropod body plans. The arthropods’ bodies vary in a multitude of parameters. With regard to locomotion physiology, important parameters are the number of propulsive legs, body size, posture and dynamics, leg design and length, timing and coordination as well as the way leg forces are generated and transferred to the ground. Force generation depends on leg muscle function and limitations thereof. Many of these parameters are limited by ambient temperatures, i.e. a constraint that has hardly been examined so far in the context of locomotion. In previous experiments, I was able to demonstrate the enormous influence of temperatures on all possible kinematic parameters for cockroaches. However, a much larger database on arthropod locomotion is needed. Therefore, I plan to investigate the locomotion of ecologically differently adapted arthropods, like faster and slower runners, with different numbers of propulsive legs, like insects and arachnids, and different body sizes, like juveniles and adults of hemimetabolous species. 3D Kinematics shall be examined for three different temperatures each. The forces transmitted by the legs to the ground and the interactions of these forces with each other determine locomotion dynamics, stability and energetics. I plan to examine ground reaction forces particularly at high running speeds in order to reveal interactions between the legs and passive contributions such as elasticity and damping for many legged designs. To complete the picture, the properties of the legs’ drives, i.e. the muscles, will be mapped using histological methods to determine myosin-ATPase activity and sarcomere lengths, which provide information on contraction speed and maximum muscle stress. For key species, the contraction properties, like the force-length relation and the force-velocity relation of functionally important leg muscles will be investigated directly. The data obtained on kinematics, dynamics and ground reaction forces of arthropod locomotion as well as on muscle contraction properties will be used for the development of a multimodal scalable 3D model. This multifaceted approach combining the examination of locomotion dynamics in fast arthropod species covering a range of locomotor apparatuses and temperature regimes, the examination of muscle properties, and the development of improved numerical models has a high potential to further integrate morphological and functional knowledge, connects function and ecology and may lead to knowledge transfer into technical implementations.