Doctoral Dissertation Research: The three-dimensional biomechanics of the grasping big toe among higher primates

University Of Missouri-Columbia, Columbia MO

Investigators

Abstract

The shift to bipedal locomotion, walking upright on two feet, a hallmark of human evolution, resulted in the adaptive loss of the grasping big toe (hallux). However, the locomotive precursor of human bipedal locomotion, and the anatomic pathway through which this change occurred, remain poorly understood. To better assess the evolution of bipedal locomotion, changes in foot anatomy and functional capacity must be examined across a broader range of primate species. This doctoral dissertation research project uses 3D imaging methods and computer algorithms to examine foot anatomy across a range of anthropoid primate species. The data generated informs the variability of foot forms in living and extinct monkeys as well as the anatomical pathways of the locomotor transition of our ancestors. Using such methods avoids damaging rare specimens and produces a freely accessible 3D atlas of the primate foot anatomy. The project supports graduate student training and mentoring in STEM and K-12 science education activities. This study documents, describes, quantifies, and compares the size, orientation, and internal architecture of the hallucal muscles across monkey species that have diverse locomotive specializations. The methods combine contrast-enhanced imaging with machine learning algorithms. The information produced allows for the development of accurate and dynamic anatomic foot models in 3D. The novel, non-destructive workflow developed in this study stands to revolutionize the ability to reconstruct musculoskeletal biomechanics in 3D in other complex anatomical systems of any vertebrate animal. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.