We have integrated muscle anatomy with bone microstructure, geometry, and applied loads to develop one of the most realistic reconstructions of salamander walking to date in order to assess the emergent properties of limb bones in the context of moving on land. A dynamic 3D musculoskeletal model of the forelimb in an adult tiger salamander (Ambystoma tigrinum) was built to simulate limb mechanics during terrestrial walking. The components of this interactive 3D musculoskeletal model included bones, joints, segment masses, and segment moments of inertia that were obtained from salamander cadavers. These data were then integrated with empirical data on the locomotor motions (kinematics) and forces (kinetics) experienced during walking in A. tigrinum. Simulations of the musculoskeletal model indicated that walking was primarily driven by motions at the shoulder and wrist. In addition, simulated muscles generally followed functions presumed in previous research with the exception that novel stabilizing functions were revealed, demonstrating the powerful insights that can be gleaned from such comprehensive computer models. Data were collected and partially processed for creating and analyzing the hindlimb model.
Information on the research have been disseminated at the 2017 Society for Experimental Biology meeting in Gothenburg, Sweden, and an invited seminar to the Palaeobiology group at the University of Bristol that was made accessible to the public through the Palaeocast podcast series. In addition, aspects related to the biomechanics of the evolutionary invasion of land by tetrapods were communicated to the public at the Royal Veterinary College Open Day event through an interactive outreach display. A journal publication on this work is in development, and ~2 others are planned to follow. The Fellow terminated the post early to accept an Assistant Professor faculty position in the U.S.A. at California State University in Long Beach, but this collaboration will continue.
