The foot is among the most frequently analyzed elements of the primate anatomy, as foot morphology is closely linked to locomotor mechanics and habitat use, and foot remains are common in the fossil record. However, despite the abundant amount of research on the shape (morphology) of the primate foot, little is known about the function of the primate foot in living animals and humans. Yet this is absolutely necessary for the interpretation of fossil foot function and understanding of the evolutionary processes by which animal postcranial design evolved in response to changing environmental conditions. This project, from the outstanding laboratory in this area of research, will apply comparative and experimental methods to the study of foot design and evolution in living apes and humans, which is the necessary first step before infering function and behavior in extinct species, including the earliest fossil human ancestors. In order to understand the development of the highly specialized foot anatomy of humans, comparisons will be made across humans, apes, and a few selected monkey species. The primary focus is on the `functional axis` of the foot, a feature usually defined morphologically by metatarsal or digital formulae or by the distribution of the intrinsic digital abductor muscles. Competing hypotheses that link morphological axes (and other features) to substrate use and specific behaviors will be tested empirically by application of simultaneous video, kinetic, and muscle monitoring electrode methodologies. This study will provide the first comprehensive data on function of the living anthropoid foot. The methods developed here will also open a new avenue for experimental research in primate locomotion that can analyze movement and force distribution within foot elements and at the interface of the foot and its substrate (ground or branches). It will also involve the training of a young professional in an outstanding laboratory.
