RUI Collaborative: Biomechanics and Control of Landing in Toads

青蛙和蟾蜍的后肢肌肉已经成为理解肌肉S在推动跳跃等推进运动中的作用的典范。任何跳跃的东西最终都必须着陆，但与跳跃过程不同的是，在跳跃过程中，肌肉产生能量来加速身体，而受控着陆需要肌肉消耗能量来减速身体。肌肉在能量消耗中的作用仍然知之甚少。这项研究将揭示与这种运动活动相关的重要原理。陆栖蟾蜍在着陆方面非常出色，它们只用前肢来减速身体。这项拟议的工作将使用蟾蜍着陆作为一个模型系统，以了解肌肉如何在撞击过程中和之后控制前肢关节的运动(肩膀、肘部和手腕)。在人类跳跃过程中，腿部肌肉的着陆前活动被用来加强关节，为着陆做准备，并根据预期的时间和撞击的大小进行调整。最近的研究表明，在半空中跳跃的蟾蜍肘关节处的肌肉活动也具有类似的先见之明。这项拟议的工作将解决其他前肢关节这种调节的着陆前活动的共性，并将专门测试这样一种假设，即它的效用在于防止参与能量消耗的肌肉在着陆过程中伸展到过长的长度，而那里最有可能发生受伤。我们还将研究视觉和本体感觉反馈在帮助动物调整肌肉活动以协调在不同高度和距离的跳跃后着陆的重要性。通过整合生物力学、肌肉生理学和感觉生物学，这项工作将突出控制减速的基本原则，这是大多数运动系统共同的动作。本科生将对这项工作的执行和展示至关重要，通过让来自当地社区学院的学生和教职员工参与，我们将扩大对前沿研究的直接参与。

The hindlimb muscles of frogs and toads have served as an exemplary model for understanding muscle?s role in powering propulsive movements like jumping. Anything that jumps must ultimately land, but unlike during jumping, where muscles produce the energy to accelerate the body, controlled landing requires muscles to dissipate energy to decelerate the body. The role of muscles during energy dissipation remains poorly understood. This research will reveal important principles associated with this locomotor activity. Terrestrial toads are outstanding at landing, using their forelimbs exclusively to decelerate their bodies. The proposed work will use toad landing as a model system for understanding how muscles control forelimb joint movements (shoulder, elbow and wrist) during and after impact. During human jumps, pre-landing activity in leg muscles is used to stiffen joints in preparation for landing, and is tuned to the expected time and magnitude of impact. Recent work demonstrates similarly prescient activity in muscles acting at the elbow joints of hopping toads in mid-air. The proposed work will address the generality of such tuned, pre-landing activity at other forelimb joints, and will specifically test the hypothesis that its utility lies in preventing muscles involved in energy dissipation from stretching to overly long lengths during landing, where injuries are most likely to occur. We will also examine the importance of visual and proprioceptive feedback in helping animals tune muscle activity to coordinate landing after hops of variable height and distance. By integrating biomechanics, muscle physiology and sensory biology this work will highlight fundamental principles governing controlled deceleration, an action common to most locomotor systems. Undergraduate students will be essential to the execution and presentation of this work, and by involving students and faculty from local community colleges, we will broaden direct participation in cutting-edge research.