Reilly 9727212 In vertebrate locomotion there is a general paradigm that limb postures in tetrapods have evolved from a sprawling posture, with the limbs held laterally to the body, to an erect posture, with the limbs held directly under the body. Accordingly, a three grade system (sprawling, semi-erect , and erect postures) has been widely used to categorize locomotor anatomies and their presumed functional mechanisms in tetrapods. However, to define and understand this biomechanical transition, we need data on the ground reaction forces generated by the footfalls of a variety of animals using different postural grades to be able to understand how the dynamics of propulsive forces change with limb position during locomotion. The goal of this project is to develop a four-step force plate system to record ground reaction forces from small vertebrate animals. The system will be designed for the size and gait characteristics of a series of vertebrates representing all of the classes. Force plates will be constructed and calibrated and then preliminary studies of representative species will be undertaken to demonstrate the utility of the system and to prepare for larger scaled integrative studies that will simultaneously record ground reaction force , kinematic and electomyographical patterns in species spanning the sprawling to erect transition.
