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的典范。在推动跳跃等运动中的作用。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，控制着陆需要肌肉消耗能量来减速身体。肌肉在能量消散过程中的作用仍然知之甚少。这项研究将揭示与这种自发活动相关的重要原则。陆栖蟾蜍在着陆时非常出色，它们只用前肢来使身体减速。拟议的工作将使用蟾蜍着陆作为模型系统，以了解肌肉如何控制前肢关节运动（肩，肘和腕）期间和之后的影响。在人类跳跃过程中，腿部肌肉中的预着陆活动被用来调整关节以准备着陆，并被调整到预期的时间和冲击力的大小。最近的研究表明，在半空中跳跃的蟾蜍手肘关节处的肌肉也有类似的先见之明。 拟议的工作将解决这种调谐的一般性，在其他前肢关节着陆前的活动，并将专门测试的假设，其效用在于防止肌肉参与能量耗散伸展到过长的长度在着陆过程中，受伤是最有可能发生的。 我们还将研究视觉和本体感受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方面的重要性。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的共同动作。本科生将是必不可少的执行和这项工作的介绍，并通过涉及学生和教师从当地社区学院，我们将扩大在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.