Kinematics and kinetics of long-axis rotation in avian bipedal locomotion

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。像人类一样，地面栖息的鸟类（鸵鸟、鸸鹋、鸡、珍珠鸡等）通过两条腿的交替运动来移动。鸟类的两足运动在二维上（从侧面看）得到了很好的描述，但肢体骨骼的三维运动从未被描述过。本研究将使用两套x射线系统，对珍珠鸡站立、以不同速度向前移动和转弯时的后肢骨骼进行高速录像。这些极其精确的运动数据将提供第一个完整的三维髋关节、膝关节和踝关节旋转描述。同时，一个高度灵敏的天平将测量脚对地面的推力。结合精确的运动（运动学）和地面力数据，可以计算骨骼、肌肉和韧带必须产生/抵抗的关节力和扭矩（动力学）。该项目的目标是了解非平面运动和载荷对鸟类两足运动的贡献。这些结果将对当今肢体设计的某些方面有所启发。这一发现有助于增强对化石的功能解释，并有可能从根本上改变科学界对奔跑脊椎动物的看法。了解鸟类三维肢体运动的机制可能会导致人类步态障碍的治疗/修复技术的进步。拟议的研究将对研究生和本科生的培训产生更广泛的影响，通过双平面x射线运动分析增强研究基础设施，并通过将当地高中科学教师纳入暑期实验室经验来扩大参与。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Like humans, ground-dwelling birds (ostriches, emus, chickens, guineafowl, etc.) move by alternate motion of their two legs. Avian bipedal locomotion is well described in two dimensions (from side view), but the movements of the limb bones in three dimensions have never been characterized. This study will use two x-ray systems to record high-speed video of the hind limb skeleton of guineafowl as they stand, move forward at different speeds, and turn. These extremely accurate motion data will provide the first complete description of 3-D hip, knee, and ankle rotations. Simultaneously, a highly sensitive scale will measure the foot's push against the ground. Combining accurate motion (kinematics) and ground force data will allow calculation of the joint forces and torques (kinetics) that bones, muscles, and ligaments must produce/resist. The project's goal is to understand the contribution of non-planar movement and loading to bipedal locomotion in birds. These results will illuminate aspects of limb design among today?s avian diversity, enhance the functional interpretation of fossils, and potentially fundamentally change the scientific community's vision of running vertebrates. Understanding the mechanisms of 3-D limb movements in birds could lead to advances in therapies/prosthetics for human gait disorders. The proposed research will have broader impacts in graduate and undergraduate student training, enhancement of research infrastructure through biplanar x-ray motion analysis, and broadening participation by including local high-school science teachers in summer lab experience.